ARMY MEDICAL LIBRARY WASHINGTON Founded 1836 WITHdhay;:i r^TEXCHANGB N.L.M. Section. Number Fobm 113c, W. D.. S. G. O. "O 3—10543 (Revised June 13, 1936) / AT* INT r g* TO *■ y//*/.)//>//>////'/?/ A r ///,)/\<^. /wert<?i with additions. /'f/j/./s///;/j By I FuiUy PhiltiWd'Brout/'ort/ii'/tfm/ Jioston. MM % AN INTRODUCTION PHYSIOLOGICAL AND SYSTEMATICAL BOTANY BY \ S JAMES EDWARD SMITHTTO). F.K.S PRESIDENT OF THE LINN-ffiAN SOCIETT; ** CONSIDEH THE HUBS OF THE FIELD, HOW THEY 6B0W." • FIRST AMERICAN, FROM THE SECOND ENGLISH EDITION ; WITH NOTES, By JACOB BIGELOW, M. D. PHILADELPHIA : PUBLISHED BY ANTHONY FINLEY, AND BRADFORD AND READ, BOSTON 1814. DISTRICT OF MASSACHUSETTS, TO WIT : District Clerk's Office. BE It remembered. That on the third day of February, A. D. 1814, and in the thirty- eighth year of the Independence of the United States of America, BRADFORD snd RF.AD, of the said district, have deposited in this office the title of a book, the right whereof they claim as Proprietors, in the words following, to wit: " An INTRODUCTION to Physiological and Systematical BOTANY. By JAMES EDWARD SMITH, M. D. F. R. S &c. 8cc. President of the Ltnnsean Society. " Con- sider the lilies of the field how they grow." First American, from the second English edition; with Notes, by JACOB BIGELOW, M.D." tn conformity to the act of the congress of the United States, entitled, " An act for the encouragement of learning, by securing the copies of maps, charts, and books, to the authors and proprietors of such copies daring the times therein mentioned ;" and also to an act, entitled, " An act supplementary to an act, entitled, an act for the encour- agement of learning, by securing the copies of maps, charts, and books, to the authors and proprietors of such copies, during the times therein mentioned ; and extending the benefits thereof to the arts of designing, engraving, and etching historical, and ether prints." nritTiiM e «u»w t Clerk of the District WU.UAM S. SHAW. } 0f Massachusetts. PRINTED BY MONROE &. FRANCIS, NO. 4, CORVHILL. ADVERTISEMENT TO THE AMERICAN EDITION. A he present edition has been undertaken from the desire of introducing in this country an elementary work, which possesses high reputation, and is now in general use in Great Britain. It very happily unites the requi- sites for an Introduction to Botany, being professedly constructed on an intelligible and popular plan, and pro- ceeding from a man, whose eminent advantages and ex- tensive learning have given authority to his name, and placed him at the head of the science in his own coun- try. In preparing for the press an American edition, some additions have been thought necessary to adapt the WITH-DSAV.:N- -F^S-EXCHANGr i* ADVERTISEMENT work to its present time and place of publication. These have been attended to, as far as the short time of preparation would admit. It will be observed, that the author, for his examples and illustrations, has principally cited English and foreign plants, contained in the English, and Exotic Botany, and the Botanical Magazine. To the greater portion of students in this country a majority of these plants, as well as their figures, are inaccessible. In order to obviate the inconvenience arising from this source, care has been taken to dis- tinguish most of those, which are native in this coun- try, and, as far as possible, to facilitate a reference to them by the insertion of their common names. Other examples taken from American plants have, also been subjoined, where additional illustrations seemed advisable. A number of physiological improvements and speculations, principally of later date than the Lon- don edition, will be found briefly detailed in the notes accompanying this. Where occasional deficiencies have been found in the definitions, the vacancy has been filled up ; as will be seen under the words calyx, petiole, &c. A table of contents has been added, and, for the benefit of those who do not possess a glossary of botan- ical terms, the general index has been increased to twice its original size. Under these circumstances, it is ADVERTISEMENT. V trusted, the present edition will not be unacceptable to the public, particularly to students attending the bo- tanical lectures in this place, for whose use it was originally undertaken. As the additions have been made in a compendious manner, and are chiefly of the mechanical kind, the editor flatters himself, they will be ascribed to a desire of rendering the work more conve- nient and useful; and not to any motives of vanity, of which he is wholly unconscious, at seeing his name on the title page. BOSTON, FEBRUARY, 1814. The Notes added to this edition are included in brackets [ ]. TO THE RIGHT HONOURABLE AND RIGHT REVEREND SHUTE, LORD BISHOP OF DURHAM. MY LORD, THE circumstances which induce me to solicit your Lordship's protection for the following pages are such, that I trust they will ensure pardon for myself, and more indulgence for my performance than, I might ex- pect, even from your Lordship's usual goodness to- wards me. The contents of these pages were, in a very unfinish- ed state, honoured with the approbation and encourage- ment of an excellent and lamented lady, to whom they were destined to be offered in their present less unwor- thy condition. I should have been proud to have shel- tered them under her patronage, because I have always found the most intelligent critics the most indulgent. Their general tendency at least, as calculated to render \n interesting and useful science accessible, and in eve- vni DEDICATION. ry point eligible, to the more accomplished and refined of her own sex, could not fail to have been approved by her^ who knew and exemplified so well the value and importance of such pursuits, and their inestimable effects upon the mind. These hopes, which my late honoured friend and patroness had, with her usual benignity, en- couraged, are now most unhappily defeated, and I have no resource but in your Lordship, who is no stranger to my pretensions, nor to my sentiments, and in whom I have not now for the first time to seek an able and en- lightened patron. I remain, with the profoundest respect, my Lord, your Lordship's most obliged and obedient servant, J. E. SMITH. Norwich, Nov. 15, 1807. CONTENTS. Page Advertisement to the American edition . . 3 Author's dedication ........ 7 Preface............ 9 Chapter I. Distinction between Animals, Vegetables, and Fossils—On the vital prin- ciple essential to the two former .... 21 Chapter II. Definition ofJ\Tatural History, and particularly Botany—Of the general texture of Plants........ 27 Chapter III. Of the Cuticle or Epider- mis .............31 Chapter IV. Of the Cellular Integument 36 * CONTENTS. Pagfe Chapter V. Of the Bud...... 38 Chapter VI. Of the Wood . . . . . 41 Chapter VII. Of the Medulla or Pith . 46 Chapter VIII. Of the Sap-Vessels, and course of the Sap ; with Mr. Knight's theory of vegetation........49 Chapter IX, Of the Sap, and Insensible Perspiration........... 63 Chapter X. Of the Secreted Fluids of Plants. Grafting. Heat of the vegetable body.............68 Chapter XI. The process of vegetation. Use of the Cotyledons ....... 87 Chapter XII. Of the Root, and its various kinds............ 94 Chapter XII. Different kinds of Stems and Stalks of Plants ........ 105 Chapter XIV. Of Buds......119 Chapter XV. Of Leaves, their situations, insertions, surfaces, and various forms . 124 Chapter XVL Of the functions of Leaves 153 CONTENTS. xi Page Chapter XVII. Of the several kinds of Fulcra, or Appendages to a Plant . . . 178 Chapter XVIII. Of the Inflorescence, or Mode of Flowering, and its various forms 187 Chapter XIX. Of the Flower and Fruit 194 Chapter XX. Of the peculiar functions of the Stamens and Pistils, with the experi- ments and observations of Linnmus and others on that subject.......246 Chapter XXI. Of the Diseases of Plants particularly as illustrative of their Vital Principle...........265 Chapter XXII. Of the Systematical Ar- rangement of Plants. Natural and Arti- ficial Methods. Genera, Species, and va- rieties. Nomenclature......273 Chapter XXIII. Explanation of the Lin- ncean and Artificial System .... 302 Chapter XXIV. Illustrations of the Lin- ncean Classes and Orders.....316 Explanation of the Plates......389 Index of Remarkable Plants^ or those of xii CONTENTS Page which any particular mention, or any change in their classification is made.....297 Index of the Explanations and Illustrations of Technical Terms, §c......402 PREFACE. After the many elementary works on Botany which have appeared in various languages, any new attempt of the same kind may, at first sight, seem unnecessary. But when we consider the rapid progress of the science within a few years, in the acquisition and determination of new plants, and especially the discoveries and im- provements in vegetable physiology : when we reflect on the views with which those fundamental works of Linnaeus, the basis of all following ones, were composed, and to whom they were addressed, we must be aware of their unfitness for purposes of general and popular* utility, and that something else is wanting. If we ex- amine the mass of introductory books on botany in this light, we shall find them in some cases too elaborate and intricate, in others too obscure and imperfect: they are also deficient in that very pleasing and instructive part of botany the anatomy and physiology of plants. There are indeed works, such as Rose's Elements of Botany, and Darwin's Phytologia, with which no such faults can be found. The former is a compendium of Lin- naean learning, the latter a store of ingenious philosophy -, R !• PREFACE. but they were designed for philosophers, and are not calculated for every reader. Linnaeus and his scholars have generally written in Latin. They address them- selves to physicians, to anatomists, to philosophers, little thinking that their science would ever be the amusing pursuit of the young, the elegant and the refined, or they would have treated the subject differently. It appears to me, therefore, that an introductory publica- tion is still desirable in this country, on an original plan, easy, comprehensive, and fit for general use, and such were the reasons which first prompted me to the under- taking. When, however, I had proceeded a considerable way in its execution, I found that such a work might not only serve to teach the first outlines of the science, but that'it might prove a vehicle for many, observations, criticisms, and communications, scarcely to be brought together on any other plan ; nor did it appear any objec- tion to the general use of the book, that, besides its primary intention, it might be capable of leading into the depths of botanical philosophy, whether physiolo- gical, systematical, or critical, any student who should be desirous of proceeding so far. A volume of this size can indeed be but elementary on subjects so exten- sive ; but if it be clear and intelligible as far as it goes, serving to indicate the scope of the science of botany. PREFACE. J) and how any of its branches may be cultivated further} my purpose is answered. The subject has naturally led me to a particular criticism of the Linnsean system of arrangements, which the public, it seems, has expect- ed from me. Without wasting any words on those speculative and fanciful changes, which the most ignor- ant may easily make, in an artificial system ; and with* out entering into controversy with the very few compe- tent writers who have proposed any alterations ; I have simply stated the result of my own practical observations, wishing by the light of experience to correct and to confirm what has been found useful, rather than rashly to overthrow what perhaps cannot on the whole be im- proved. As the discriminating characters of the Linnaean sys- tem are founded in nature and fact, and depend upon parts essential to every species of plant when in perfec- tion ; and as the application of them to practice iSj above all other systems, easy and intelligible ; I conceive noth- ing more useful can be done than to perfect, upon its own principles, any parts of this system that experience may show to have been originally defective. This is all I presume to do. Speculative alterations in an arti- ficial system are endless, and scarcely answer any more useful purpose than changing the order of letters in an alphabet. The philosophy of botanical arrangement, or 12 PREFACE. the study of the natural affinities of plants, is quite an- other matter. But it would be as idle, while we pursue this last-mentioned subject, so deep and so intricate that its most able cultivators are only learners, to lay aside the continual use of the Linnaean system, as it would be for philologists and logicians to slight the convenience, and indeed necessity, of the alphabet, and to substitute the Chinese character in its stead. If the following pages be found to elucidate and to confirm this compar- ison, I wish the student to keep it ever in view. The illustration of the Linnaean system of classifica- tion, though essential to my purpose, is however but a small part of my aim. To explain and apply to practice those beautiful principles of method, arrangement and discrimination, which render botany not merely an amusement, a motive for taking air and exercise, or an assistance to many other arts and sciences ; but a school for the mental powers, an alluring incitement for the young mind to try its growing strength, and a confirma- tion of the most enlightened understanding in some of its sublimest most important truths. That every path tending to ends so desirable may be accessible, I have not confined myst If to systematical subjects, wide and various as they are, but I have introduced the anatomy and physiology of plants to the botanical student, wish- ing to combine all these several objects ; so far at least PREFACE. lj. that those who do not cultivate them all, may be sensible of the value of each in itself, and that no disgraceful ri- valship or contempt, the offspring of ignorance, may be felt by the pursuers of any to the prejudice of the rest. I have treated of physiological and anatomical subjects in the first place, because a true knowledge of the struc- ture and parts of plants seems necessary to the right understanding of botanical arrangement; and I trust the most superficial reader will here find enough for that purpose, even though he should not be led to pur- sue these subjects further by himself. I have every where aimed at familiar illustrations and examples, refer- ring, as much as possible, to plants of easy acquisition. In the explanation of botanical terms and characters, I have, besides furnishing a new set of plates with referen- ces to the body of the work, always cited a plant for my purpose by its scientific name, with a reference to some good and sufficient figure. For this end I have generally used either my own works English and Exotic Botany, all the plates of which, as well as of the present volume, are the performance of the same excellent botanist as well as artist ; or Curtis's Magazine, much of which also was drawn by Mr. Sowerby. I have chosen these as the most comprehensive and popular books, quoting others only when these failed me, or when I had some particular end in view. If this treatise should be adopted 14 PREFACE. for general use in schools or families, the teacher at least will probably be furnished with those works, and will accommodate their contents to the use of the pupils. I am aware of the want of a systematical English descrip- tion of British plants, on the principles of this Introduc- tion ; but that deficiency I hope as soon as possible to supply. In the mean while Dr. Withering's work may serve the desired purpose, attention being paid only to his original descriptions, or to those quoted from Eng- lish writers. His index will atone for the changes I o cannot approve in his system. Wherever my book may be found deficient in the explanation of his or any other terms, as I profess to retain only what are necessary, or in some shape useful, the Language of Botany, by Pro- fessor Martyn, will prove extremely serviceable. Having thus explained the use and intention of the present work, perhaps a few remarks on the recommen- dations of the study of Botany, besides what have already been suggested, may not here be misplaced. I shall not labour to prove how delightful and instruc- tive it is to " Look through Nature up to Nature's God." Neither, surely, need I demonstrate, that if any judi- cious or improved use is to be made of the natural bodies around us, it must be expected from those who discrim- inate their kinds and study their properties. Of the t PR'FACE. 15 benefits of natural science in the improvement of many arts, no one doubts. Our foodvour physic, our luxuries are improved by it. By the inquiries of the curious new acquisitions are made in remote countries, and our re- sources of various kinds are augmented. The skill of Linnaeus by the most simple observation, founded how- ever on scientific principles, taught his countrymen to destroy an insect, the Cantharis navalis, which had cost the Swedish government many thousand pounds a year by its ravages on the timber of one dockyard only. After its metamorphoses, and the season when the fly laid its eggs, were known, all its ravages were stopped by immersing the timber in water during that period. The same, great observer, by his botanical knowledge, detected the cause of a dreadful disease among the horn- ed cattle of the north of ^Lapland, which had previously been thought equally unaccountable and irremediable, and of which he has given an exquisite account in his Lapland tour, as well as under Cicuta virosa, Enjl. Bot. t. 479, in his Flora Lapponica. O-ie man in our days, by his scientific skill alone, had given the bread-fruit to the West-Indies, and his country justly honours his character and pursuits. All this is acknowledged. We are no longer in the infancy of science, in which its utility, not having been proved, might be doubted, nor is it for this that I contend. I would recommend bota- 16 PREFACE. ny for its own sake. I have often alluded to its benefits as a mental exercise, nor can any study exceed it in raising curiosity, gratifying a taste for beauty and inge- nuity of contrivance, or sharpening the powers of dis- crimination. What then can be better adapted for young persons ? The chief use of a great part of our education is no other than what I have just mentioned. The languages and the mathematics, however valuable in themselves when acquired, are even more so as they train the youthful mind to thought and observation. In Sweden, Natural History is the study of the schools, by which men rise to preferment; and there are no people with more acute or better regulated minds than the Swedes. To those whose minds and understandings are already formed, this study may be recommended, indepen- dently of all other considerations, as a rich source of innocent pleasure. Some people are ever inquiring " what is the use" of any particular plant, by which they mean " what food or physic, or what materials for the painter or dyer does it afford ?" They look on a beautiful flowery meadow with admiration, only in pro. portion as it affords nauseous drugs or salves. Others consider a botanist with respect only as he may be able to teach them some profitable improvement in tanning, or dyeing, by which they may quickly grow rich, and PREFACE. 17 be then perhaps no longer of any use to mankind or to themselves. They would permit their children to study botany, only because it might possibly lead to profes- sorships, or other lucrative preferment. These views are not blameable, but they are not the sole end of human existence. Is it not desirable to call the soul from the feverish agitation of worldly pursuits, to the contemplation of Divine Wisdom in the beautiful ceconomy of Nature ? Is it not a privilege to walk with God in the garden of creation, and hold converse with his providence ? If such elevated feelings do not lead to the study of Nature, it cannot far be pursued without rewarding the student by exciting them. Rousseau, a great judge of the human heart and ob- server of human manners, has remarked, that " when science is transplanted from the mountains and woods into cities and worldly society, it loses its genuine charms, and becomes a source of envy," jealousy and rivalship," This is still more true if it be cultivated as a mere source of emolument. But the man who loves botany for its own sake knows no such feelings, nor is he dependent for happiness on situations or scenes that favour their growth. He would find himself nei- ther solitary nor desolate, had he no other companion than a " mountain daisy," that "modestcrimson-tipped IS PREFACE. flower," so sweetly sung by one of Nature's own poets. The humblest weed or moss will ever afford him some- thing to examine or to illustrate, and a great deal to ad- mire. Introduce him to the magnificence of a tropical forest, the enamelled meadows of the Alps, or the won- ders of New Holland, and his thoughts will not dwell much upon riches or literary honours, things that « Play round the head, but come not near the heart." One idea is indeed worthy to mix in the pure con- templation of Nature, the anticipation of the pleasure we may have to bestow on kindred minds with our own, in sharing with them our discoveries and our acquisi- tions. This is truly an object worthy of a good man, the pleasure of communicating virtuous disinterested pleasure to those who have the same tastes with our- selves ; or of guiding young ingenuous minds to wor- thy pursuits, and facilitating their acquisition of what we have already obtained. If honours and respectful consideration reward such motives, they flow from a pure source. The giver and the receiver are alike in- vulnerable, as well as inaccessible, to " envy, jealousy or rivalship," and may pardon their attacks without an effort. The natural history of animals, in many respects even more interesting than botany to man as an animated being, and more striking in some of the phenomena PREFACE. 19 which it displays, is in other points less pleasing to a tender and delicate mind. In botany all is elegance and delight. No painful, disgusting, unhealthy experi- ments or inquiries are to be made. Its pleasures spring up under our feet, and, as we pursue them, reward us with health and serene satisfaction. None but the most foolish or depraved could derive any thing from it but what is beautiful, or pollute its lovely scenery with una- miable or unhallowed images. Those who do so, either from corrupt taste or malicious design, can be compared only to the fiend entering into the garden of Eden, Let us turn from this odious picture to the contem- plation of Nature, ever new, ever abundant in inex- haustible variety. Whether we scrutinize the damp recesses of woods in the wintry months, when the numerous tribes of mosses are displaying their minute, but highly interesting structure ; whether we walk forth in the early spring, when the ruby tips of the haw- thorn-bush give the first sign of its approaching vegeta- tion, or a little after, when the violet welcomes us with its scent, and the primrose with its beauty ; whether we contemplate in succession all the profuse flowery treasures of the summer, or the more hidden secrets of Nature at the season when fruits and seeds are forming; the most familiar objects, like old friends, will always afford us something'to study and to admire in their 20 PREFACE. characters, while new discoveries will awaken a train of new ideas. The yellow blossoms of the morning, that fold up their delicate leaves as the day advances ; others that court and sustain the full blaze of noon ; and the pale night-scented tribe, which expand, and diffuse their very sweet fragrance, towards evening, will all please in their turn. Though spring is the season of hope and novelty, to a naturalist more especially, yet the wise provisions and abundant resources of Nature, in the close of the year, will yield an observing mind no less pleasure, than the rich variety of her autumnal tints affords to the admirers of her external charms. The more we study the works of the Creator, the more wis- dom, beauty and harmony become manifest, even to our limited apprehensions ; and while we admire, it is im- possible not to adore. " Soft roll your incense, herbs, and fruits, and flowers, In mingled clouds, to Him, whose sun exalts, Whose breath perfumes you, and whose pencil paints !" INTRODUCTION TO PHYSIOLOGICAL AND SYSTEMATICAL BOTANY- CHAPTER I. DISTINCTIONS BETWEEN ANIMALS, VEGETABLES, AND FOS- SILS.—ON THE VITAL PRINCIPLE ESSENTIAL TO THE TWO FORMER. X hose who with a philosophical eye have contempla- ted the productions of Nature, have all, by common consent, divided them into three great classes, called the Animal, the Vegetable, and the Mineral or Fossil King- doms. These* terms are still in general use, and the most superficial observer must be struck with their propriety. The application of them seems at first sight perfectly easy, and in general it is so. Difficulties occur to those only who look very deeply into the subject. Animals have an organized structure which regularly unfolds itself, and is nourished and supported by air and food ; they consequently possess life, and are sub- ject to death ; they are moreover endowed with sensa- tion, and with spontaneous, as well as voluntary, motion. 22 DISTINCTIONS BETWEEN ANIMALS Vegetables are organized, supported by air and food, endowed with life and subject to death as well as ani- mals. They have in some instances spontaneous, though we know not that they have voluntary, motion. They are sensible to the action of nourishment, air, and light, and either thrive or languish according to the wholesome or hurtful application of these stimulants. This is evident to all who have ever seen a plant growing in a climate, soil, or situation, not suitable to it. Those who have ever gathered a rose, know but too well how soon it withers ; and the familiar application of its fate to that of human life and beauty is not more striking to the imagination than philosophically and literally true. The sensitive plant is a more astonishing example of the capability of vegetables to be acted upon as living bodies. Other instances of the same kind we shall hereafter have occasion to mention. The spontaneous movements of plants are almost as readily to be observed as their living principle. The general direction of their branches, and especially of the upper surface of their leaves, though repeatedly disturb- ed, to the light ; the unfolding and closing of their flowers at stated times, or according to favourable or unfavourable circumstances, with some still more curi- ous particulars to be explained in the sequel of this work, are actions undoubtedly depending on their vital principle, and are performed with the greater facility in proportion as that principle is in its greatest vigour. Hence arises a question whether Vegetables are endowed with sensation. As they possess life, irritability and motion, spontaneously directing their organs to what is AND VEGETABLES. 23 natural and beneficial to them, and flourishing according to their success in satisfying their wants, may not the exercise of their vital functions be attended with some degree of sensation, however low, and some consequent share of happiness ? Such a supposition accords with all the best ideas we can form of the Divine Creator ; nor could the consequent uneasiness which plants must suf- fer, no doubt in a very low degree likewise, from the depredations of animals, bear any comparison with their enjoyment on the whole. However this may be, the want of sensation is most certainly not to be proved with regard to Vegetables, and therefore of no use as a practical means of distinguishing them, in doubtful eases, from Animals. Some Philosophers* have made a locomotive power peculiarly characteristic of Animals, not being aware of the true nature of those half-animated beings called Corals and Corallines, which are fixed, as immoveably as any plants, to the bottom of the sea, while indeed many living vegetables swim around them, unattached to the soil, and nourished by the water in which they float, f Some have characterized Animals as nourished by their internal, and Vegetables by their external sur- face, the latter having no such thing as an internal stomach. This is ingenious and tolerably correct; but the proofs of it must fail with respect to those minute and simply-constructed animals the Polypes, and the lower tribes of Worms, whose feelers, put forth into the water, seem scarcely different from roots seeking * Jungius, Boerhaave, Ludwig and many others. t Dr. Alston, formerly professor of botany at Edinburgh. 24 MINERAL KINGDOM. their food in the earth, and some of which may be turned inside out, like a glove, without any disturbance of their ordinary functions. The most satisfactory re- mark I have for a long time met with on this difficult subject is that of M. Mirbel, in his Traite d'Anatomie et de Physiologie Vegetales* a work I shall often have occasion to quote. He observes, vol. I. p. 19, " that plants alone have a power of deriving nourishment, though not indeed exclusively, from inorganic matter, mere earths, salts or airs, substances certainly incapable of serving as food for any animals, the latter only feeding on what is or has been organized matter, either of a vegetable or animal nature. So that it should seem to be the office of vegetable life alone to transform dead matter into organized living bodies." This idea ap- pears to me so just, that I have in vain sought for any exception to it. Let us however descend from these philosophical speculations to purposes of practical utility. It is suffi- cient for the young student of Natural History to know, that in every case in which he can be in doubt whether he has found a plant or one of the lower orders of ani- mals, the simple experiment of burning will decide the question. The smell of a burnt bone, coralline, or other animal substance, is so peculiar that it can never be mistaken, nor does any known vegetable give out the same odour.(l) * Published at Paris two or three years since, in 2 vols. 8vo. (1) [It has been remarked that some vegetable products, such as the gluten of wheat, caoutchonc, and the juice of the papaw tree ; give out in burning nearly the same peculiar odour which is afforded by animal matter.! ON THE VITAL PRINCIPLE. 25 The Mineral Kingdom can never be confounded with the other two. Fossils are masses of mere dead unor- ganized matter, subject to the laws of chemistry alone j growing indeed, or increasing by the mechanical addi- tion of extraneous substances, or by the laws of chem- ical attraction, but not fed by nourishment taken into an organized structure. Their curious crystallization bears some resemblance to organization, but performs none of its functions, nor is any thing like a vital principle to be found in this department of Nature. If it be asked what is this vital principle, so essential to animals and vegetables, but of which fossils are desti- tute, we must own our complete ignorance. We know it, as we know its Omnipotent Author, by its effects. Perhaps in the fossil kingdom heat may be equivalent to a vital principle ; but heat is not the vital principle of organized bodies, though probably a consequence of that principle. Living bodies of animals and plants produce heat ; and this phenomenon has not, I think, been entirely explained on any chemical principles, though in fossils the production of heat is in most cases tolerably well accounted for. In animals it seems to have the closest possible connexion with the vital energy. But the ef- fects of this vital energy are still more stupendous in the operations constantly going on in every organized body, from our own elaborate frame to the humblest moss or fungus. Those different fluids, so fine and transparent separated from each other by membranes as fine, which compose the eve, all retain their proper situations D *6 ON THE VITAL PRINCIPLE. (though each fluid individually is perpetually removed and renewed) for sixty, eighty, or a hundred years, or more, while life remains. So do the infinitely small vessels of an almost invisible insect, the fine and pellu- cid tubes of a plant, all hold their destined fluids, con- veying or changing them according to fixed laws, but never permitting them to run into confusion, so long as the vital principle animates their various forms. But no sooner does death happen, than, without any alteration of structure, any apparent change in their material con- figuration, all is reversed. The eye loses its form and brightness ; its membranes let go their contents, which mix in confusion, and thenceforth yield to the laws of chemistry alone. Just so it happens, sooner or later, to the other parts of the animal as well as vegetable frame. Chemical changes, putrefaction and destruction, imme- diately follow the total privation of life, the importance of which becomes instantly evident when it is no more. I humbly conceive therefore, that if the human under- standing can in any case flatter itself with obtaining, in the natural world, a glimpse of the immediate agency of the Deity, it is in the contemplation of this vital principle, which seems independent of material organization, and. an impulse of his own divine energy. C sr ] CHAPTER II. DEFINITION OF NATURAL HISTORY, AND PARTICULAR! \ BOTANY—OF THE GENERAL TEXTURE OF PLANTS. Natural History properly signifies that study by which we learn to distinguish from one another the natural bodies, whether Animal, Vegetable or Mineral, around us ; to discover as much as possible their nature and properties, and especially their natural dependence on each other in the general scale of beings. In a more extensive sense it may be said to teach their secondary properties, or the various uses to which they have been, or may be, converted, in the service of mankind or of other animals ; inasmuch as an acquaintance with their natural qualities is our only sure guide to a knowledge of their artificial uses. But as this definition would in- clude many arts and sciences, each of them sufficient to occupy any common mind, as Agriculture, Dietetics, Medicine, and many others, it is sufficient for a philo- sophical naturalist to be acquainted with the general principles upon which such arts and sciences are founded. That part of Natural History which concerns plants is called Botany, from Berisunce nece&sar), and hf* 48 OF THE MEDULLA OR PITH. has actually traced a direct communication by vessels between it and the leaf. " Plants," says that ingenious writer, " seem to require some such reservoir ; for their young leaves are excessively tender, and they perspire much, and cannot, like animals, fly to the shade and the brook." This idea of Mr. Knight's may derive considerable support from the consideration of bulbous-rooted grass- es. The Common Catstail, Phleum pratense, Engl. Bot. t. 1076, when growing in pastures that are uni- formly moist, has a fibrous root, but in dry situations, or such as are only occasionally wet, it acquires a bul- bous one, whose inner substance is moist and fleshy, like the pith of young branches of trees. This is evi- dently a provision of Nature to guard the plant against too sudden a privation of moisture from the soil. But, on the other hand, all the moisture in the me- dulla of a whole branch is, in some cases, too little to supply one hour's perspiration of a single leaf. Neither can I find that the moisture of the medulla varies, let the leaves be ever so flaccid. I cannot but incline therefore to the opinion that the medulla is rather a re- servoir of vital energy, even in these bulbous grasses. Mr. Knight has shown that the part in question may be removed without any great injury to a branch, or at least without immediate injury, but I have had no op- portunity of making any experiments on this particular subject. [ 49 j CHAPTER VIIT. OF THE SAP-VESSELS, AND COURSE OF THE SAP ; WITH ME KNIGHT'S THEORY OF VEGETATION. Much contrariety of opinion has existed among phys- iologists concerning the vascular system of plants, and the nature of the propulsion of the sap through their stems and branches. Indeed it is a subject upon which, till lately, very erroneous ideas have prevailed. That the whole vegetable body is an assemblage of tubes and vessels is evident to the most careless observ- er ; and those who are conversant with the microscope, and books relating to it, have frequent opportunities of observing how curiously these vessels are arranged, and how different species of plants, especially trees, differ from each other in the structure and disposition of them. Such observations, however, if pursued no further, lead but a little way towards a knowledge of the wonderful physiology of vegetables. In our 2d chapter, mention is made of the general cellular and vascular texture of plants ; we must now be a little more particular in our inquiries. That plants contain various substances, as sugar, gum, acids, odoriferous fluids and others, to which their various flavours and qualities are owing, is familiar to every one ; and a little reflection will satisfy us that such substances must each be lodged in proper cells and ves- sels to be kept distinct from each other. They are ex- tracted, or secreted, from the common juice of the plant, and called its peculiar or secreted fluids. Various ex- r; « 50 OF THE SAP-VESSELS. periments and observations, to be hereafter enlarged up- on, prove also that air exists in the vegetable body, and must likewise be contained in appropriate vessels. Be- sides these, we know that plants are nourislied and invi- gorated by water, which they readily absorb, and which is quickly conveyed through their stalks and leaves, no doubt by tubes or vessels on purpose. Finally, it is ob- servable that all plants, as far as any experiment has been made, contain a common fluid, which at certain seasons of the year is to be obtained in great quantity, as from vine branches by wounding them in the spring before the leaves appear, and this is properly called the sap. It is really the blood of the plant, by which its whole body is nourished, and from which the peculiar secretions are made. The great difficulty has been to ascertain the vessels in which the sap runs. Two of the most distinguished inquirers into the subject, Malpighi and Grew, believed the woody fibres, which make so large a part of trie vegetable body, and give it consistence and strength, to be the sap-vessels, analogous to the blood-vessels of animals, and their opinion was adopted by Du Hamel. In support of this theory it was justly observed that these fibres are very numerous and strong, running longitudi- nally, often situated with great uniformity (an argument for their great importance,) and found in all parts of a plant, although in some they are so delicate as to be scarcely discernible. But philosophers sought in vain for anv perforation, any thing like a tubular structure, in the woody fibres to countenance this hypothesis, for they are divisible almost without end, like the muscular OF THE SAP-VESSELS. 51 fibre. This difficulty was overlooked, because of the necessity of believing the existence of sap-vessels some- where ; for it is evident that the nutrimental fluids of a plant must be carried with force towards certain parts and in certain directions, and that this can be accom- plished by regular vessels-bnly, not, as Tournefort sup- posed, by capillary attraction through a simple spongy or cottony substance. I received the first hint of what I now believe to be the true sap-vessels from the 2d section 6f Dr. Darwin's Phytologia, where it is suggested that what have been taken for air-vessels are really absorbents destined to nourish the plant, or, in other words, sap-vessels. The same idea has been adopted, confirmed by experiments, and carried to much greater perfection by Mr. Knight, whose papers in the Philosophical Transactions for 1801, 1804 and 1805 throw the most brilliant light upon it, and, I think, established no less than an entirely new theory of vegetation, by which the real use and func- tions of the principal organs of plants are now for the first time satisfactorily explained. In a young branch of a tree or shrub, or in the stem of an herbaceous plant, are found, ranged round the centre or pith, a number of longitudinal tubes or vessels, of a much more firm texture than the adjacent parts, and when examined minutely, these vessels often appear to be constructed.with a spiral coat. This may be seen in the young twigs and leaf stalks of Elder, Syringa, and many other shrubs, as well as in numerous herba- ceous plants, as the Peony, and more especially many of the Lily tribe. If a branch or stalk of any of these $2 OF THE SAP-VKSSKLS. plants be partly cut through or gently broken, and its divided portions slowly drawn asunder, the spiral coats of their vessels will unroll, exhibiting a curious specta- cle even to the naked eye. In other cases, though the spiral structure exists, its convolutions are scarcely se- parable at all, or so indeterminate as to be only marked by an interrupted line of perforations or slits, as shown by M. Mirbel. Indeed the very same branches which exhibit these spiral vessels when young, show no signs of them at a more ^advanced period of growth, when their parts are become more woody, firm, and rigid. No such spiral-coated vessels have been detected in the bark at any period of its growth. Malpighi asserts that these vessels are always found to contain air only, no other fluid ; while Grew reports that he sometimes met with a quantity of moisture in them. Both judged them to be air-vessels, or, as it were, the lungs of plants, communicating, as these phi- losophers presumed, with certain vessels of the leaves and flowers, of an oval or globular form, but destitute of a spiral coat. These latter do really contain air, but it rather appears from experiment that they have no di- rect communication with the former. Thus the tubes in question have always been called air-vessels, till Dar- win suggested their real nature and use.* He is per- haps too decisive when he asserts that none of them are air-vessels because they exist in the coot, which is not exposed to the atmosphere. We know that air acts upon the plant under ground, because seeds will not * Du Hamel, indeed, once suspected that they contained ;< highly rarefied sap," but did not pursue the idea. DR DARWIN'S EXPERIMENTS. 5* vegetate in earth under the exhausted receiver of an air- pump. Phil. Trans. No. 23. I do not however mean to contend that any of these spiral vessels are air-vessels, nor do I see reason to believe that plants have any sys- tem of longitudinal air-vessels at all, though they must be presumed to abound in such as are transverse or hor- izontal. Dr. Darwin and Mr. Knight have, by the most sim- ple and satisfactory experiment, proved these spiral vessels to be the channel through which the sap is con- veyed. The former placed leafy twigs of a common Fig-tree about an inch deep'in a decoction of madder, and others in one of logwood. After some hours, on cutting the branches across, the coloured liquors were found to have ascended into each branch by these vessels, which exhibited a circle of red dots round the pith, sur- rounded by an external circle of vessels containing the white milky juice, or secreted fluid, so remarkable in the fig-tree. Mr. Knight, in a similar manner, inserted the lower ends of some cuttings of the Apple-tree and Horse-chesnut into an infusion of the skins of a very black grape in water, an excellent liquor for the pur- pose. The result was similar. But Mr. Knight pur- sued his observations much further than Dr. Darwin had done ; for he traced the coloured liquid even into the leaves, " but it had neither coloured the bark nor the sap between it and the wood ; and the medulla was not affected, or at most was very slightly tinged at its edges." Phil. Trans, for 1801, p. 335. The result of all Mr. Knight's experiments and re- marks seems to be, that the fluids destined to nourish a 54 MR. KNIGHT'S EXPERIMENTS. plant, being absorbed by the root and become sap, are carried up into the leaves by these vessels, called by him central vessels, from their situation near the pith. A particular set of them, appropriated to each leaf, branches off, a few inches below the leaf to which they belong, from the main channels that pass along the alburnum, and extend from the fibres of the root to the extremity of each annual shoot of the plant. As they approach the leaf to which they are destined, the central vessels be- come more numerous, or subdivided. " To these ves- sels," says Mr. Knight, " the spiral tubes are every where appendages." p. 336. By this expression, and by a passage in the following page,* 337, this writer might- seem to consider the spiral line, which forms the coats of these vessels, as itself a pervious tube, or else that he was speaking of other tubes with a spiral coat, companions of the sap-vessels ; but the plate which ac- companies his dissertation, and the perspicuous mode in which he treats the subject throughout, prevent our mistaking him on the last point. In order to conceive how the sap can be so powerfully conveyed as it is through the vessels in which it flows, from the root of a tall tree to its highest branches, we must take into con- sideration the action of heat. We all know that this is necessary to the growth and health of plants ; and that it requires to be nicely adjusted in degree, in order to suit * " The whole of the fluid, which passes from the wood to the leaf, seems to me evidently to be conveyed through a single kind of vessel ; for the spiral tubes will neither carry coloured infusions, nor in the smallest degree retard the withering of the, leaf, when the central vessels are divided." Knight, PROPULSION OF THE SAP. 5-5 the constitutions of different tribes of plants destined for different parts of the globe. It cannot but act as a stim- ulus to the living principle, and is one of the most pow- erful agents of Nature upon the vegetable as well as animal constitution. Besides this, however, various mechanical causes may be supposed to have their effect; as the frequently spiral or screw-like form of the vessels, in some of which, when separated from the plant, Mal- pighi tells us he once saw a very beautiful undulating motion that appeared spontaneous. This indeed has not been seen by any other person, nor can it be sup- posed that parts so delicate can, in general, be removed from their natural situation, without the destruction of that fine irritability on which such a motion must de- pend. We may also take into consideration the agitation of the vegetable body by winds, which is known by experience to be so wholesome to it,* and must serve powerfully to propel the fluids of lofty trees ; the pas- sage, and evolution perhaps, of air in other parts or ves- sels surrounding and compressing these ; and lastly the action, so ingeniously supposed by Mr. Knight, of those thin shining plates called the silver grain, visible in oak wood, which passing upon the sap-vessels, and being apparently susceptible of quick changes from variations in heat or other causes, may have a powerful effect. " Their restless temper," says Mr. Knight, " after the tree has ceased to live, inclines me to believe that they are not made to be idle whilst it continues alive." Phil. * See Mr. Knight's experiments in confirmation of this in the Phil. Trans, for 1803, fi. 208. 56 ACTION 01- THE SUA KR CHAIN. Trans, for 1801,/>. 344. These plates are presumed by the author just quoted to be peculiarly useful in as- sisting the ascent of the sap through the alburnum of the trunk or chief branches, where indeed the spiral coats of the vessels are either wanting, or less elastic than in the leaf-stalks and summits of the more tender shoots. However its conveyance may be accomplished, it is certain that the sap does reach the parts above mention- ed, and there can surely be now as little doubt of the vessel* in which it runs. That these vessels have been thought to contain air only, is well accounted for by Dr. Darwin, on the principle of their not collapsing when emptied of their sap ; which is owing to their rigidity, and the elastic nature of their coats. When a portion of a stem or branch is cut off, the sap soon exhales from it, or rather is pushed out by the action of the vessels themselves : hence they are found empty ; and for the same reason the arteries of animals were formerly thought to contain air only. When the sap-vessels have parted with their natural contents, air and even quicksilver will readily pass through them, as is shown by various experiments. Arguments in support of any theory must be very cautiously deduced from such ex- periments, or from any other observations not made on vegetables in their most natural state and condition ; and, above all, that great agent the vital principle must always be kept in view, in preference to mere mechanical con- siderations. These to which I give the common name of sap- vessels, comprehending the common tubes of the albur- COURSE OF THE SAP. 57 num, and the central vessels, of Mr. Knight, may be considered as analogous to the arteries of animals ; or rather they are the stomach, lacteals and arteries all in one, for I conceive it to be a great error in Dr. Darwin to call by this name the vessels which contain the pecu- liar secretions of the plant.* These sap-vessels, no doubt, absorb the nutritious fluids afforded by the soil, in which possibly, as they pass through the root, some change analogous to digestion may take place ; for there is evidently a great difference, in many cases, between the fluids of the root, at least the secreted ones, and those of the rest of the plant ; and this leads us to pre- sume that some considerable alteration may be wrought in the sap in its course through that important organ. The stem, which it next enters, is by no means an es- sential part, for we see many plants whose leaves and flowers grow directly from the root. Part of the sap is conveyed into the flowers and fruit, where various fine and essential secretions are made from it, of which we shall speak hereafter. By far the greater portion of the sap is carried into the leaves, of the great importance and utility of which to the plant itself Mr. Knight's theory is the only one that gives us any adequate or satisfactory notion. In those organs the sap is exposed to the action of light, air and mois- ture, three powerful agents, by which it is enabled to form various secretions, at the same time that much su- perfluous matter passes off by perspiration. These secretions not only give peculiar flavours and qualities u * Phytologia, sect. 2. ss COURSE OF THE SAP. to the leaf itself, but are returned by another set of ves* sels, as Mr. Knight has demonstrated, into the new layer of bark, which they nourish and bring to perfection, and which they enable in its turn to secrete matter for a new layer of alburnum the ensuing year. It is presum- ed that one set of the returning vessels of trees may probably be more particularly destined to this latter office, and another to the secretion of peculiar fluids in the bark. See Phil. Trans, for 1801, p. 337. In the bark principally, if I mistake not, the peculiar secretions of the plant are perfected, as gum, resin, &c. each un- doubtedly in an appropriate set of vessels. From what has just been said of the office of leaves, we readily per- ceive why all the part of a branch above a leaf or leaf- bud dies when cut, as each portion receives nourish- ment, and the means of increase, from the leaf above it. By the above view of the vegetable ceconomy, it ap- pears that the vascular system of plants is strictly annual. This, of course, is admitted in herbaceous plants, the existence of whose stems, and often of the whole indi- vidual, is limited to one season ; but it is no less true with regard totrees.(4) The layer of alburnum on the (4) [The effect of girdling trees, as practised in new settle- ments in the United States, is readily explained on the theory of Mr. Knight. In this operation a circle of bark and also of the alburnum or outer wood is removed from around the trunk. A check is thus put both to the ascent and descent of the sap, and the tree dies in consequence sooner or later. Sometimes how- ever the sap ascends through a trunk which has been girdled, and the tree puts out leaves in the ensuing summer. This fact is not explained by the p.i.iciples here laid down, but agrees with a subsequent paper of Mr. xvnight {Phil. Trans. 1808) in which COURSE OF THE SAP. 59 «ne hand is added to the wood, and the liber, or inner layer of the bark, is on the other annexed to the layers he concludes that the ceUular substance gives passage to the sap. Though the conclusions of this paper can hardly be ad- mitted in their full extent, it is nevertheless probable that the cellular substance of the trunk may exert a vicarious office and afford a temporary passage to the sap when its proper vessels are interrupted. If a ring of bark only is removed, the sap may continue to as- cend with freedom, but is obstructed in its descent. This ope- ration may be performed with perfect safety to the tree, provid- ed the ring taken out is sufficiently narrow, so that the space may be filled up with new bark from above, during the same season. In trees which form new bar,, readily upon the surface »f the alburnum, as in the instance page 45, the whole trunk may be stripped with impunity, and sometimes with advantage to the future health and productiveness of the tree. It is how- ever often necessary that the trunk should be artificially covered during the reproduction of the bark. Du Hamel mentions trees in perfect health 15 or 18 years after having been thus depriv- ed ot their bark. Some improvements in the cultivation of fruits have been founded upon the intersection of the bark. BufFon removed a girdle of bark, 3 inches in width, from the trunks of some fruit trees, and found that they produced blossoms and fruit 3 weeks sooner than the other trees in their neighbourhood. Mr Wil- liams in the Transactions of the Horticultural Society, states that grapes came to maturity much earlier, were larger, and better flavoured, when a small circle of bark, one or two eighths of an inch in width, was removed from around the alburnum of the fruitful branches, while the fruit was in its young state. This method is annually practised in the vicinity of Boston by differ- ent individuals with the best success. The explanation depends on the theory of Mr. Knight, the sap being interrupted in its de« scent, and confined to the branches above the incision, so that 3. greater quantity of it goes to nourish the fruit.^ 60 GROWTH OF MONOCOTYLEDONE5. formed in the preceding seasons, and neither have any share in the process of vegetation for the year ensuing. Still, as they continue for a long time to be living bodies, and help to perfect, if not to form, secretions, they must receive some portion of nourishment from those more active parts which have taken up their late functions. There is a tribe of plants called monocotyledones, having only one lobe to the seed,* whose growth re- quires particular mention. To these belongs the natu- ral order of Palms, which being the most lofty, and, in some instances, the most long-lived of plants, have justly acquired the name of trees. Yet, paradoxical as it may seem, they are rather perennial herbaceous plants, hav- ing nothing in common with the growth of trees in general. Their nature has been learnedly explained by M. Desfontaines, a celebrated French botanist, and by * M. Mirbel in his Traite d'Anatomie et de Physiology Vegetales, vol. 1. p 209, and Linnaeus has long ago made remarks to the same purpose. The Palms are formed of successive circular crowns of leaves, which spring directly from the root. These leaves and their footstalks are furnished with bundles of large sap- vessels and returning vessels, like the leaves of our trees. When one circle of them has performed its office, an- other is formed within it, which being confined below, necessarily rises a little above the former. Thus suc- cessive circles grow one above the other, by which the vertical increase of the plant is almost without end. Each circle of leaves is independent of its predecessor, and has its own clusters of vessels, so that there can be * Or rather no true cotyledon at all. OF REVERSED PLANTS. 61 no aggregation of woody circles ; and yet in some of this tribe the spurious kind of stem, formed in the man- ner just described, when cut across shows something of a circular arrangement of fibres, arising from the origi- nal disposition of the leaves. The common orange lily, Lilium bulbiferum, Curt. Mag. t. 36, and white lily, L. candidum, t. 278, which belong to the same natural family called monocotyledones, serve to elucidate this subject. Their stems, though of only annual duration, are formed nearly on the same principle as that of a Palm, and are really congeries of leaves rising one above an- other, and united by their bases into an apparent stem. In these the spiral coats of the sap-vessels are very easily discernible. To conclude this subject of the propulsion of the sap, it is necessary to say a few words on the power which the vessels of plants are reported to possess of convey- ing their appropriate fluids equally well in either direc- tion ; or, in other words, that it is indifferent whether a cutting of any kind be planted with its upper or lower end in the ground. On this subject also Mr. Knight has afforded us new information, by observing that, in cuttings so treated, the returning vessels retain so much of their original nature as to deposit new wood above the leaf-buds ; that is, in the part of the cutting which, if planted in its natural position, would have been below them. \t appears, however, that the sap-vessels must absorb and transmit their sap in a direction contrary to what is natural; and it is highly probable, that, after some revolving seasons, new returning vessels would be formed in that part of the stem which is now below the $2 OF REVERSED PLANTS. buds. I presume there can be no doubt that success. sive new branches would deposit their wood in the usual position. It is nevertheless by no means common for such inverted cuttings to succeed at all. An ex- periment to a similar purpose is recorded by Dr. Hales, Vegetable Staticks, p. 132, t. 11, of engrafting together three trees standing in a row, and then cutting off the communication between the central one and the earth, so that it became suspended in the air, and was nourished merely through its lateral branches. The same e xper- iraent was successfully practised by the late Dr. Hope at Edinburgh upon three Willows, and in the years 1781, 2, and 3, I repeatedly witnessed their health and vigour. It was observed that the central trte was sev- eral days later in coming into leaf than its supporters, but I know not that any other difference was to be per- ceived between them. The tree which wanted the sup- port of the ground was, some years after, blown down, so that we have now no opportunity of examining the course of its vessels, or the mode in which successive layers of wood were deposited in its branches ; but the experiment is easily repeated. In the weeping variety of the Common Ash, now so frequent in gardens, the branches are completely inver- ted as to position, yet the returning fluids appear to run exactly in their natural direction, depositing new wood, as they are situated above the buds or leaves ; and if the end of any branch be cut, all beyond (oi below) the next bud dies ; so that in this case gravitation, to which Mr. Knight attributes considerable power over the returning fluids, Phil. Trans, for 1804, does not counteract the ordinary course of nature. [ 63 ] l* CHAPTER IX. OF THE SAP, AND INSENSIBLE PERSPIRATION1-. The sap of trees, as has been mentioned in .the last chapter, may be obtained by wounding a stem or branch in spring, just before the buds open, or in the end of au- tumn, though less copiously, after a slight frost ; yet not during the frost. In the Palm-trees of hot coun- tries, it is said to flow from a wound at any time of the year. It has always been observed to flow from the young wood or alburnum of our trees, not from the bark ; which agrees with Mr. Knight's theory. A common branch of the Vine cut through will yield about a pint of this fluid in the course of twenty-four hours. The Birch, Betula alba, affords plenty of sap ; some other trees yield but a small quantity. It flows equally upward and downward from a wound, at least proportionably to the quantity of stem or branch in eith- er direction to supply it. Some authors have asserted that in the heat of the day it flows most from the lower part of a wound, and in the cool of the evening from the upper; hence they concluded it was ascending during the first period, and descending in the latter. If the fact be true some other solution must be sought ; nor would it be difficult to invent a theory upon this subject: but we rather prefer the investigation of truth on more solid foundations. This great motion, called the flowing, of the sap, which is to be detected principally in the spring, and slightly in the autumn, is therefore totally distinct from 64 OF THE SAP, that constant propulsion of it going on in every growing plant, about which so much has been said in the pre- ceding chapter, and which is proved by taking an entire herb of any kind that has been gathered and suffered to begin to fade, and immersing its root in water. By absorption through the sap-vessels it presently revives, for those vessels require a constant supply from the root. This flowing of the sap has been thought to demon- strate a circulation, because, there being no leaves to car- ry it off by perspiration, it is evident that, if it were at these periods running up the sap-vessels with such ve- locity, it must run down again by other channels. As soon as the leaves expand, its motion is no longer to be detected. The effusion of sap from plants, when cut or wounded, is, during the greater part of the year, compar- atively very small. Their secreted fluids run much more abundantly. I conceive therefore that this flowing is nothing more than a facility in the sap to run, owing to the peculiar irritability of the vegetable body at the times above men- tioned ; and that it runs only when a wound is made, being naturally at rest till the leaves open, and admit of its proper and regular conveyance. Accordingly, lig- atures made at this period, which show so plainly the course of the blood in an animal body, have never been found to throw any light upon the vegetable circulation. This great facility in the sap to run is the first step to- wards the revival of vegetation from the torpor of win- ter ; and its exciting cause is heat, most unquestionably by the action of the latter on the vital principle, and AND INSENSIBLE PERSPIRATION. 65 scarcely by any mechanical operation, or expansive pow- er upon the fluids. The effect of heat is in proportion to the degree of cold to which the plant has been accus- tomed. In forced plants the irritability, or, to use the words of a late ingenious author*, who has applied this principle very happily to the elucidation of the animal (Economy, excitability, is exhausted, as Mr. Knight well remarks, and they require a stronger stimulus to grow with vigour. Seep. 91. Hence vegetation goes on better in the increasing heat of spring than in the de- creasing heat of autumn. And here I cannot but offer, by way of illustration, a remark on the theory advanced by La Cepede, the able continuator of Buffon, relative to serpents. That ingenious writer mentions, very tru- ly, that these reptiles awake from their torpid state in the spring, while a much less degree of heat exists in the atmosphere than is perceptible in the autumn, when, seemingly from the increasing cold, they become be- numbed ; and he explains it by supposing a greater de- gree of electricity in the air at the former season. Dr. Brown's hypothesis, of their irritability being as it were accumulated during winter, offers a much better solution, either with respect to the animal or vegetable constitu- tion. For the same reason, it is necessary to apply warmth very slowly and carefully to persons frozen, or even chilled only, by a more than usual degree of cold, which renders them more susceptible of heat, and a tem- perate diet and very moderate stimulants are most safe * Dr. John Brown, formerly of Edinburgh. See the 14th Section of Dr. Darwin's Phytologia on this subject. I 66 OF THE SAP, and useful to the unexhausted constitutions of children. The same principle accounts for the occasional flowing of the sap in autumn after a slight frost. Such a piema- ture cold increases the sensibility of the plant to any warmth that may follow, and produces, in a degree, the same state of its constitution as exists after the longer and severer cold of winter. Let me be allowed a fur- ther illustration from the animal kingdom. Every body conversant with labouring cattle must have observed how much sooner they are exhausted by the warm days of autumn, when the nights are cold, than in much hot- ter weather in summer, and this is surely from the same cause as the autumnal flowing of the vegetable sap.(5) The sap, or lymph, of most plants when collected in the spring as above mentioned, appears to the sight and taste little else than water, but it soon undergoes fermen- tation and putrefaction. Even that of the Vine is scarcely acid, though it can hardly be obtained without (5) [In addition to the above explanation of the flowing of the sap, we may subjoin one which has been suggested, but not enlarged on, by Mr. Knight. In the spring of the year the sap begins to ascend from the root sometime before the expan- sion of the buds. As at this time there are no leaves, flowers, Sec. on which the sap may be expended, the trunk becomes overcharged with it, and will readily bleed if wounded. After the leaves are developed, and the growth of the new layer of wood has commenced, all the sap from the trunk is required to afford the material for the new growth, and to supply the pro- digious expenditure by perspiration from the leaves At this period no sap flows from incisions in the trunk. In autumn after a frost has taken place, the functions of the leaves are suddenly checked, the sap is again restricted to the trunk, the vessels .ire again overcharged with fluid, and will bleed again if divided.] AND INSENSIBLE PERSPIRATION. 67 some of the secreted juices, which in that plant are ex- tremely acid and astringent. The sap of the Sugar Maple, Acer saccharinum, has no taste, though according to Du Hamel every 2001b. of it will afford 101b. of sugar. Probably, as he remarks, it is not collected without an admixture of secreted fluids. As soon as the leaves expand, insensible perspiratioa takes place very copiously, chiefly from those organs, but also in some degree from the bark of the young stem or branches. The liquor perspired becomes sensible to us by being collected from a branch introduced into any sufficiently capacious glass vessel, and proves, for the most part, a clear watery liquor like the sap, and subject to similar chemical changes. It is observed to be uniform in all plants, or nearly so, as well as the sap, except where odorous secretions transude along with it. Still there must be a very essential difference between the original sap of any plant and its perspiration, the lat- ter no longer retaining the rudiments of those fine secre- tions which are elaborated from the former ; but that difference eludes our senses as well as our chemistry. The perspiration of some plants is prodigiously great. Tl)e large Annual Sunflower, Helianthus annuus, Ger- arde Emac. 751. f. I, according to Dr. Hales, perspires about 17 times as fast as the ordinary insensible perspi- ration of the human skin. But of all plants upon record I think the Cornelian Cherry, Cornus mascula, is most excessive in this respect. The quantity of fluid which evaporates from its leaves in the course of 24 hours, is said to be nearly equal to twice the weight of the whole shrub. Du Hamel Phys. des Arbres, v. 1. 145, [ 68 ] CHAPTER X. QF THE SECRETED FLUIDS OF PLANTS. GRAFTING. HEAT OF THE VEGETABLE BODY. The sap in its passage through the leaves and bark becomes quite a new fluid, possessing the peculiar fla- vour and qualities of the plant, and not only yielding woody matter for the increase of the vegetable body, but furnishing various secreted substances, more or less nu- merous and different among themselves. These ac- cordingly are chiefly found in the bark ; and the vessels containing them often prove upon dissection very large and conspicuous, as the turpentine-cells of the Fir tribe. In herbaceous plants, whose stems are only of annual duration, the perennial roots frequently contain these fluids in the most perfect state, nor are they, in such, confined to the bark, but deposited throughout the sub- stance or wood of the root, as in Rhubarb, Rheum pal- amatum, Linn. fil. Fasc. t. 4, and Gentian, Gentian lutea and purpurea, Ger. emac. 482, f. 1, 2. In the wood of the Fir indeed copious depositions of turpen- tine are made, and in that of every tree more or less of a gummy, resinous, or saccharine matter is found. Such must be formed by branches of those returning vessels that deposit the new alburnum. These juices appear to be matured, or brought to greater perfection, in layers of wood or bark that have no longer any principal share in the circulation of the sap, The most distinct secretions of vegetables require to Jje enumerated under several different heads. SECRETED FLUIDS. 63 Gum or mucilage, a viscid substance of little flavour or smell, soluble in water, is very general. When su- iperabundant it exudes from many trees in the form of large drops or lumps, as in Plum, Cherry, and Peach- trees, and different species of Mimosa or Sensitive plants, one of which yields the Gum Arabic, others the Gum Senegal, &c.(6) Resin is a substance soluble in spirits, and much more various in different plants than the preceding, as the Turpentine of the Fir and Juniper, the Red Gum of New South Wales, produced by one or more species oi Eucalyptus, Bot. of N. Holl. t. 13, and the fragrant Yellow Gum of the same country, see White's Voyage, 235, which exudes spontaneously from the Xanthorrhcea Hastile. Most vegetable exudations partake of a nature between these two, being partly soluble in water, partly in spirits, and are therefore called Gum-resins. The milky juice of the Fig, Spurge, &c, which Dr. Darwin has shown, and which every body may see, to be quite distinct from the sap, is, like animal milk, an emulsion, or combination of a watery fluid with oil or resin. Ac- cordingly, when suffered to evaporate in the air, such fluids become resins or gum-resins, as the Gum Eu- phorbium. In the Celandine, Chelidonium majus, Engl. (6) [Mucilage is found in great quantities in the root of Al- thea officinalis, or Marsh Mallow, in the inner bark of Slippery Elm (Ulmusfulva), in the pith of Sassafras, in the leaves of different Mallows, Violets, &c. on the seeds of Quinces and Flax.] 70 RESINOUS SECRETIONS. Bot. t. 1581, and some plants allied to it, the emulsion is orange-coloured.(7) The more refined and volatile secretions of a resinous nature are called Essential Oils, and are often highly aromatic and odoriferous. One of the most exquisite of these is afforded by the Cinnamon bark. They exist in the highest perfection in the perfumed effluvia of flowers, some of which, capable of combination, with spirituous fluids, are obtainable by distillation, as that of the Lavender and Rose ; while the essential oil of the Jasmine is best procured by immersing the flowers in expressed oil which imbibes and retains their fra- grance. Such Expressed or Gross Oils, as they are called, to distinguish them from essential oils obtained by distillation, are chiefly found in the seeds of plants. In the pulp of the Olive indeed they occur in the form of an emulsion, mixed with watery and bitter fluids, from which the oil easily separates by its superior lightness. These expressed oils are not soluble in spirits or water, (7) [The resinous juice, known in the northern states by the name of Fir balsam, is a spontaneous exudation from the Pinus Balsamea, retained in little sacs or vesicles upon the bark. Turpentine is obtained in great quantities from the North American Pines, particularly Pinus Palustris, by incisions or excavations in the trunk. When Turpentine is distilled, the Oil of Turpentine comes over, and Resin remains behind. Tar is obtained from the resinous treea by a slow combustion of their wood. Wax is a vegetable product. It exists on the surface of leaves, and probably in the pollen of flowers. It is obtained in large quantities from the berries of Myrica Ccrifcra, Bayberry bush, or Wax Myrtle ; by boiling the berries in water until the wax melts and floats upon the surface.] BITTER SECRETION. ti though by certain intermediate substances they may be rendered capable of uniting with both. The Bitter secretion of many plants does not seem exactly to accord with any of the foregoing. Some facts would seem to prove it of a resinous nature, but it is often perfectly soluble in water. Remarkable instan- ces of this secretion are in the Cinchona officinalis or Peruvian bark, Lambert Cinchona, t. 1, and every spe- cies, more or less, of Gentian.(8) Acid secretions are well known to be very general in plants. Formerly one uniform vegetable or acetous acid was supposed common to all plants ; but the refine- ments of modern chemistry have detected in some a peculiar kind, as the Oxalic acid, obtained from Oxalis or Wood Sorrel, and several others. The astringent principle should seem to be a sort of acid, of which there are many different forms or kinds, and among them the tanning principle of the Oak, Willow, &c.(9) (8) [The Gentiana safionaria and Gentiana Crinita are two •f our most beautiful autumnal plants. The root of the first is decidedly bitter. The roots of Goldthread (Helleborus trifolius), of Hydras- tis Canadensis, and Zanthorhiza Afiiifolia contain the bitter prin- ciple in great abundance. See Professor Barton's Materia Medica of the United States.^ (?) [Among the North-American Oaks, most esteemed for tanning, are the Quercus alba, or White Oak, the Quercus vir- ens, or Live Oak of the southern states, Quercus tinctoria, or Black Oak, Quercus falcata, or Spanish Oak, and Quercus firi- mus monticola, or Rock Chesnut Oak, For the investigation of this important genus, as well as for their other laoours, we are 72 ACID AND ALKALIXE SECRETIONS. On the other haud, two kinds of Alkali are furnished by vegetables, of which the most general is the Vegeta- ble Alkali, properly so called, known by the name of Salt of Tartar, or Salt of Wormwood, or more correctly by the Arabic term Kali. The Fossil Alkali, or Soda,. is most remarkable in certain succulent plants that grow near the sea, belonging to the genera Chenopodium, Sal- sola, Etc. When these plants are cultivated in a com- mon soil, they secrete Soda as copiously, provided their health be good, as in their natural maritime places of growth. Sugar, more or less pure, is very generally found in plants. It is not only the seasoning of most eatable fruits, but abounds in various roots, as the Carrot, Beet and Parsnip, and in many plants of the grass or cane kind besides the famous Sugar Cane Saccharum offici- narum. There is great reason to suppose Sugar not so properly an original secretion, as the result of a chemical change in secretions already formed, either of an acid or mucilaginous nature, or possibly a mixture of both. In ripening fruits this change is most striking, and takes place very speedily, seeming to be greatly promoted by heat and light. By the action of frost, as Dr. Darwin observes, a different change is wrought in the mucilage of the vegetable body, and it becomes starch. A fine red 'liquor is afforded by some plants, as the Bloody Dock or Rumex sanguineus, Engl. Bot. t. 1533, the Red Cabbage and Red Beet, which appears only to deeply indebted to those two distinguished botanists, the elder and younger Michaux.] VARIETIES OF SECRETIONS. mark a variety in all these plants, and not to constitute a specific difference. It is however perpetuated by seed. It is curious to observe, not only the various secre- tions of different plants, or families of plants, by which they differ from each other in taste, smell, qualities and medical virtues, but also their great number, and strik- ing difference, frequently in the same plant. Of this the Peach-tree offers a familiar example. The gum of this tree is mild and mucilaginous. The bark, leaves, and flowers abound with a bitter secretion of a purgative and rather dangerous quality, than frhich nothing can be more distinct from the gum. The fruit is replete, not only with acid, mucilage and sugar, but with its own peculiar aromatic and highly volatile secretion, elabor rated within itself, on which its fine flavour depends. How far are we still from understanding the whole anat- omy of the vegetable body, which can create and keep separate such distinct and discordant substances ! Nothing is more astonishing than the secretion of flinty earth by plants, which, though never suspected till within a few years, appears to me well ascertained. A substance is found in the hollow stem of the Bamboo, (Arundo Bambos of Linnaeus, Nastos of Theophrastos,) called Tabaxir or Tabasheer, which is supposed in the East Indies (probably because it is rare and difficult of acquisition, like the imaginary stone in the head of a toad) to be endowed with extraordinary virtues. Some of it, brought to England, underwent a chemical exam, inalion, and proved, as nearly as possible, pure flint. See Dr. Russell's and Mr, Macie's papers on the sub. K- 74 FLINTY SECRETION. ject in the Phil. Trans, for 1790 and 1791. It is even found occasionally in the Bamboo cultivated in our hot- houses. But we need not search exotic plants for flinty earth. I have already, in speaking of the Cuticle, chap. ter 3d, alluded to the discoveries of Mr. Davy, Professor of Chemistry at the Royal Institution, on this subject. That able chemist has detected pure flint in the cuticle of various plants of the family of Grasses, in the Cane (a kind of P >lm) and in the Rough Horsetail, Equisetum hyemale, Engl. Bot. t. 915. (10) In the latter it is very copious, and so disp6sed as to.make a natural file, which renders this plant useful in various manufactures, for even brass cannot resist its action: Common Wheat straw, when burnt, is found to contain a portion of flinty earth in the form of a most exquisite powder, and this accounts for the utility of burnt straw in giving the last polish to marble. How great is the contrast between this production, if it be a secretion, of the tender vege- table frame, and those exhalations which constitute the perfume of flowers ! One is among the most permanent substances in Nature, an ingredient in the primeval mountains of the globe ; the other the invisible untan- gible breath of a moment ! The odour of plants is unquestionably of a resinous nature, a volatile essential oil and several phzenomena attending it well deserve our attentive consideration, Its general nature is evinced by its ready union with spirits or oil, not with water ; yet the moisture of the atmosphere seems, in many instances, Dowerfully to fa- (10) [Used in this country under the name pf Scouring Rush."] ODOUR OF PLANTS. 75 vour its diffusion. This I apprehend to arise more from the favourable action of such moisture upon the health and vigour of the plant itself, thus occasionally promot- ing its odorous secretions, than from the fitness of the atmosphere, so circumstanced, to convey them. Both causes however may operate. A number of flowers which have no scent in the course of the day, smell pow- erfully in an evening, whether the air be moist or dry, or whether they happen to be exposed to it or not. This is the property of some which Linnaeus has elegantly called flores tristes, melancholy flowers, belonging to various tribes as discordant as possible, agreeing only in their nocturnal fragrance, which is peculiar, very sim- ilar and exquisitely delicious in all of them, and in the pale yellowish, greenish, or brownish tint of their flow- ers. Among these are Mesembryanthemum noctiflorum, Dill. Elth. t. 206, Pelargonium triste, Cornut. Canad. 110, and several species akin to it, Hesperis tristis, Curt. Mag. t. 730, Cheiranthus tristis, t. 729, Daphne pontica, Andrews's Repos. t. 73, Crassula odoratissima, t. 26, and many others*. A few more, greatly resembling these in the green hue of their blos- soms, exhale, in the evening chiefly, a most powerful * These flowers afford the Poet a new image, which is in- troduced into the following imitation of Martial, and offered here ^lely for its novelty : Go mingle Arabia's gums With the spices all India yields. Go crop each young flower as it blooms. Go ransack the gardens and fields. Let ;\0 SMELL OF NEW HAY lemon-like scent, as Epidendrum ensifolium, Sm. Spicit. t. 24, and Chloranthus inconspicuus, Phil. Trans, for 1787, t. 14, great favourites of the Chinese, who seem peculiarly fond of this scent. There are other instances of odorous and aromatic secretions, similar among them- selves, produced by very different plants, as Camphor. The sweet smell of new hay is found not only in An* thoxanthum odoratum, Engl. Bot. t. 647, and some other grasses, but in Woodruff or Asperula odorata, t. 755, Melilot or Trifolium officinale, t. 1340, and all the varieties, by some deemed species,. of Orchis m litaris, t. 16 and t. 1873, plants widely different from each other in botanical characters, as well as in colour and every particular except smell. Their odour has one peculiarity, that it is not at all perceptible while the plants are growing, nor till they begin to dry. It pro- ceeds from their whole herbage, and should seem to es- cape from the orifices of its containing cells, only when Let Paestum's all-flowery groves Their roses profusely bestow. Go catch the light zephyr that roves Where the wild thyme and marjoram grow.- Let every pale night-scented flower, Sad emblem of passion forlorn, Resign its appropriate hour, To enhance the rich breath of the morn. All that art or that nature can find, Not half so delightful would prove, Nor their sweets all together combined, Half so sweet as the breath of my love. BITTER-ALMOND FLAVOUR. /f" the surrounding vessels, by growing less" turgid, with- draw their pressure from such orifices. When this scent of new hay is vehement, it becomes the flavour of bitter almonds. The taste of syrup of capillaire, given by an infusion of Orange flowers, is found in the her- bage of Gaultheria procun.bensy(l\) Andr. Repos. 1.116, and Spircea Ulmaria, Engl. Bot. t. 960, two very differ- ent plants. Some of the above examples show an evident analogy between the smell and colours of flowers, nor are they all that might be pointed out.' A variety of the Chrysan- themum indicum with orange-coloured flowers has been lately procured from China by Lady Amelia Hume. These faintly agree in scent, as they do in colour, with the Wall-flower, Cherianthus Cheiri ; whereas the com- mon purple variety of the same Chrysanthemum has a totally different and much stronger odour. There is, of course, still more analogy between the smell of plants in general and their impression on the palate, insomuch that we are frequently unable to dis- criminate between the two. The taste is commonly more permanent than the smell, but now and then less so. The root of the Arum maculatum, Engl; Bot. t. 1298, for instance, has, when fresh, a most acrid taste and irritating quality, totally lost by drying, when the root becomes simply farinaceous,tasteless and inert;(12) so that well might learned physicians contrive the (11) [Partridge berry of the United States.] (12) [The same properties occur in the Arum trifihyllum, o* Indian Turnip, common throughout the United States.] 78 COLOURS OF FLAM'S. •' Compound Powder of Arum," to excuse the continu- ance of its use in medicine, unless they had always pre- scribed the recent plant.—Many curious remarks are to be found in Grew relative to the tastes of plants, and their different modes of affecting our organs. Anatomy of Plants, p. 279—292. To all the foregoing secretions of vegetables may be added those on which their various colours depend. We can but imperfectly account for the green so uni- versal in their herbage, but we may gratefully ack- nowledge the beneficence of the Creator in clothing the earth with a colour the most pleasing and the least fa- tiguing to our eyes. We may be dazzled with the brilliancy of a flower-garden, but we repose at leisure on the verdure of a grove or meadow. Of all greens the most delicate and beautiful perhaps is displayed by several umbelliferous plants under our hedges in the spring. Some of Nature's richest tints and most elegant com- binations of colour are reserved for the petals of flowers, the most transient of created beings ; and even during the short existence of the parts they decorate, the co- lours themselves are often undergoing remarkable varia- tions. In the pretty little weed called Scorpion-grass, Myosotis scorpioides, Engl. Bot. t. 480, and several of its natural order, the flower-buds are of the most deli- cate rose-colour, which turns to a bright blue as they open. Many yellow flowers under the influence of light become white. Numbers of red, purple or blue ones are liable, from some unknown cause in the plant to which they belong, to vary to white. Such varieties COLOURS OF PLANTS. are sometimes propagated by seed, and are almost inva- riably permanent if the plants be propagated by roots, cuttings or grafting. Plants of an acid or astringent nature often become very red in their foliage by the ac- tion of light, as in Rumex, Polygonum, Epilobium and Berberis ; and it is remarkable that American plants in general, as well as such European ones as are par- ticularly related to them, are distinguished for assuming various rich tints in their foliage of red, yellow, white or even blue, at the decline of the year, witness the Guelder-rose, the Cornel, the Vine, the Sumach, the Azalea pontica, Curt. Mag. t. 433, and others. Fruits for the most part incline to a red colour, apparently from the acid they contain. I have been assured by a first-rate chemist that the colouring principle of the Raspberry is a fine blue, turned red by the acid in the fruit. The juices of some Fungi, as Boletus bovinus and Agaricus deliciosus, Sowerb. Fungi, t, 202, change almost instantaneously on exposure to the air, from yel- low to dark blue or green. These are a few hints only on a subject which opens a wide field of inquiry, and which, in professedly chem- ical works, is carried to a greater length than I have thought necessary in a physiological one. See Thom- son's Chemistry, v. 4, and Wildenow's Principles of Botany, 229. We must ever keep in mind, as we ex- plore it, that our anatomical instruments are not more inadequate to dissect the organs of a scarcely distin- guishable insect, than our experiments are to investigate the fine chemistry of Nature, over which the living prin- ciple presides. 80 Uses of the Before we take leave of the secreted fluids oi vegeta. bles, a few more remarks upon their direct utility to the plants themselves may not be superfluous. Malpighi first suggested that these secretions might nourish the plant, and our latest inquiries confirm the suggestion. Du Hamel compares them to the blood of animals, and so does Darwin. But the analogy seems more plain between the sap, as being nearly uniform in all plants, and the animal blood, as in that particular they accord, while the secreted fluids are so very various. Mr. Knight's theory confirms this analogy, at the same time that it establishes the opinion of Malpighi. The sap returning from the leaf, where it has been acted upon by the air and light, forming new wood, is clearly the cause of the increase of the vegetable body. But it is not so clear how the resinous, gummy or other secretions, laid aside, as it were, in vessels, out of the great line of cir- culation, can directly minister to the growth of the tree. I conceive they may be in this respect analogous to ani- mal fat, a reservoir of nourishment whenever its ordina- ry supplies are interrupted, as in the winter, or in seasons of great drought, or of unusual cold. In such circum- stances the mucilaginous or saccharine secretions espe- cially, perhaps the most general of all, may be absorbed into the vegetable constitution ; just as fat is into the animal one, during the existence of any disease that in- terrupts the ordinary supplies of food, or interferes with its due appropriation. It is well known that such ani* mals as sheep through the winter, grow fat in the autumn and awake very lean in the spring. Perhaps the more recent layers of wood in a Plum- or Cherry-tree, if they SECRETED FLUIDS. 81 could be accurately examined, might be found to con- tain a greater proportion of mucilage at the end of au- tumn than in the early spring. If these substances do not nourish the plant, they seem to be of no use to it, whatever secondary purposes they may answer in the schemes of Providence. The direct end, with respect to the plant, of the finer secreted fluids of its fruit can very well be perceived, as tempting the appetite of an- imals, and occasioning, through their means, the disper- sion of the seeds ; and the perfume of flowers may at- tract insects, and so promote the fertilization of the seed, as will be explained hereafter. After what has been said, we need not waste much time in considering the hypothesis, advanced by some philosophers, that the sap-vessels are veins and the re- turning vessels arteries. This is so far correct, that, as the chyle prepared by the digestive organs, poured into the veins and mixed with the blood, is, through the me- dium of the heart, sent into the lungs to be acted upon by the air ; so the nutrimental juices of plants, taken up from the earth, which has been called their stomach, are carried by the sap-vessels into the leaves, for similar purposes already mentioned. The improved sap, like the vivid arterial blood, then proceeds to nourish and invigorate the whole frame. I very much doubt, how- ever, if those who suggested the above hypothesis could have given so satisfactory an explanation of it. That the secretions of plants are wonderfully constant appears from the operation of grafting. This consists in uniting the branches of two or more separate trees, as r. 82 GRAFTING Dr. Hope's Willows, see p. 62, and a whole row of Lime-trees in the garden of New College, Oxford, whose branches thus make a network. This is called grafting by approach. A more common practice, called budding, or inoculating, is to insert a bud of one tree, accompanied by a portion of its bark, into the bark of another, and the tree which is thus engrafted upon is ealied the stock. By this mode different kinds of fruits, as apples, pears, plums, &c, each of which is only a variety accidentally raised from seed, but no further perpetuated in the same manner, are multiplied, buds of the kind wanted to be propagated being engrafted on so many stocks of a wild nature. The mechanical part of this practice is detailed in Du Hamel, Miller, and most gardening books. It is of primary importance that the liber, or young bark, of the bud, and that of the stock, should be accurately united by their edges. The air and wet must of course be excluded. It is requisite for the success of this operation that the plants should be nearly akin. Thus the Chionan- thus virginica, Fringe-tree, succeeds well on the Com- mon Ash, Fraxinus excelsior, by which means it is propagated in our gardens. Varieties of the same spe- cies succeed best of all ; but Apples and Pears, two dif- ferent species of the same genus, may be grafted on one stock. The story of a Black Rose being produced by grafting a common rose, it is not worth inquiring which, on a black currant stock, is, as far as I can learn, with- out any foundation, and is indeed at the first sight absurd. I have known the experiment tried to no purpose. The rose vulgarly reported to be so produced is merely a HEAT OF VEGETABLES. S3 dark Double Velvet Rose, a variety, as we presume of Rosa centifolia. Another report of the same kind has been raised concerning the Maltese Oranges, whose red juice has been attributed to their being budded on a Pomegranate stock, of which I have never been able to obtain the smallest confirmation. Heat can scarcely be denominated a secretion, and yet is undoubtedly a production, of the vegetable as well as animal body, though in a much lower degree in the former than the latter. The heat of plants is evinced by the more speedy melting of snow when in contact with their leaves or stems, compared with what is lodg- ed upon dead substances, provided the preceding frost has been sufficiently permanent to cool those substances thoroughly. Mr. Hunter appears to have detected this heat by a thermometer applied in frosty weather to the internal parts of vegetables newly opened. It is evident that a certain appropriate portion of heat is a necessary stimulus to the constitution of every plant, without which its living principle is destroyed. (13) l Most tropical plants are as effectually killed by a freezing de- gree of cold, as by a boiling heat, and have nearly the (13) [The tendency of plants is to preserve an uniform tem- perature, and to resist both, heat and cold. Fruits and leaves, situated in the sun, preserve themselves cool, while surrounding objects are heated. Sonnerat discovered in the island of Lucon a rivulet, the water of which was so hot, that a thermometer im- mersed in it rose to 175° Fahr. Swallows when flying seven feet high over it dropped down motionless. Notwithstanding the heat, lie observed on its banks two species of Asfialathus, and the Vitex agnus castus, which with their roots swept the water. In the island of Tanna, Messrs. Forsters found the 81 FORCING OF PL\NTS- same appearance ; which is exemplified every autumn in the Garden Nasturtium, Tropaolum majus. The vegetables of cold climates, on the contrary, support a much greater degree of cold without injury, at least while in a torpid state ; for when their buds begin to expand they become vastly more sensible, as is but too frequently experienced in the fickle spring of our climate. Nor is this owing, as vulgarly supposed, merely to the greater power of the cold to penetrate through their opening buds. It must penetrate equally through them in the course of long and severe winter frosts, which are never known to injure them. The extremely pernicious effects therefore of cold on open- ing buds can only be attributed to the increased suscep- tibility of the vital principle, after it has been revived by the warmth of spring. The vegetation of most plants may be accelerated by artificial heat, which is called forcing them, and others may, by the same means, be kept in tolerable health, ground near a volcano as hot as 210°, and at the same time cov- ered with flowers. See Willdenow's Principles of Botany. In a similar manner the plants of high latitudes are capable of withstanding intense and long continued cold. Acerbi, in his travels in Sweden and Lapland, found Pines, Firs, and Birches from Tornea almost to the North Cape. Mackenzie, in latitude about 69,near the Frozen ocean, found the ground in July cover- ed with short grass and flowers, though the earth was not thaw- ed above four inches from the surface, beneath which was a solid body of ice. In the island of Spitzbergcn, there grow not less than thirty species of plants. In these climates, vegetation is exceedingly rapid during the few months which permit it.] HEAT OF THE ARUM. 85 under a colder sky than is natural to them. But many alpine plants, naturally buried for months under a deep snow, are not only extremely impatient of sharp frosts, but will not bear the least portion of artificial heat. The pretty Primula marginata, Curt. Mag. t. 191, if brought into a room with a fire when beginning to blos- som, never opens another bud ; while the American Cowslip, Dodecatheon Meadia, t. 12, one of the most hardy of plants with respect to cold, bears forcing ad- mirably well. Mr. Knight very satisfactorily shows, Phil. Trans. for 1801, 343, that plants acquire habits with regard to heat which prove their vitality, and that a forced Peach- tree will in the following season expand its buds pre- maturely in the open air, so as to expose them to inev- itable destruction. See p. 65. A thousand parallel instances may be observed, by the sagacious gardener, of plants retaining the habits of their native climates, which very often proves one of the greatest impediments to their successful cultivation. The most remarkable account that has fallen in my way concerning the production of heat in plants, is that given by Lamarck in his Flore Franchise, v. 3. 538, of the common Arum maculatum, Engl. Bot. t. 1298, (the white-veined variety,) the flower of which, at a cer- tain period of its growth, he asserts to be, for a few hours, " so hot as to seem burning." The learned M. Sene- bier of Geneva, examining into this fact, discovered that the heat began when the sheath was about to open, and the cylindrical body within just peeping forth : and that it was perceptible from about three or four o'clock 86 HEAT OF THE ARUM. in the afternoon till eleven or twelve at night. Its great- est degree was seven of Reaumur's scale above the heat of the air, which at the time of his observation was about fourteen or fifteen of that thermometer. Such is the ac- count with which I have been favoured by Dr. Bostock of Liverpool, from a letter of M. Senebier*, dated Nov. 28, 1796, to M. De la Rive. I have not hitherto been successful in observing the phcenomenon in question, which however is well worthy of attention, and may probably not be confined to this species of Arum. * It is now published in his Physiologie Vegetale, v. 3. 314, where nevertheless this ingenious philosopher has declared his opinion to be rather against the existence of a spontaneous heat in vegetables, and he explains even the above striking phaenom- enon upon chemical principles, which seem to me very inadequate. I 87 ] CHAPTER XI. THE PROCESS OF VEGETATION. USE OF THE COTYLEDONS When a seed is committed to the ground, it swells by the moisture which its vessels soon absorb, and which, in conjunction with some degree of heat, stimulates its vital principle. Atmospherical air is also necessary to incipient vegetation, for seeds in general will not grow under water, except those of aquatic plants, nor under an exhausted receiver; and modern chemists have de- termined oxygen gas, which is always an ingredient in our atmosphere, to be absorbed by seeds in vegetation. An experiment is recorded in the Philosophical Trans- actions, No. 23, of sowing Lettuce-seed in two separ- ate pots, one of which was placed in the common air, the other in the vacuum of an air-pump. In the form- er the young plants rose to the height of two inches, or more, in a week's time ; in the other none appeared, till after the pot had been removed for a similar period into the air again. Seeds buried in the ground to a greater depth than is natural to them do not vegetate, but they often retain thei> power of vegetation for an unlimited period. Earth taken from a considerable depth will, when exposed to the air, be soon covered with young plants, especially of Thistles, or of the Cress or Mustard kind, though no seeds have been allowed to have access to it. If the ground in old established botanic gardens be dug much deeper than ordinary, it frequently happens that species which have been long 8S ( PROCESS OF VEGETABLES. lost are recovered, from their seeds being latent in the soil, as I have been assured by Mr. Fairbairn of Chelsea garden, and others.( 14) The integuments of the seed, having, fulfilled their destined office of protection, burst and decay. „The young root is the first part of the infant plant that comes forth, and by an unerring law of Nature, it is sent down- wards, to seek out nourishment as well as to fix the plant to the ground. In sea-weeds, Fuci, Ulv) t. 313, the French Bean, Phaseolus vulgaris, Ger. em. 1212, fig. 1, &c.-^-Figures of plants being sometimes re- versed by the engraver, in that case give a wrong rep- resentation of the circumstance in question, witness Lonicera Periclymenum in Curtis's Flora Londinen- sis, fasc. 1. t. 15, and many instances might be pointed out of its not being attended to at all. Flagellformis, long and pliant, like the Common Jas- mine, Jasminum officinale, Curt. Mag. t. 31, or. Blue Box-thorn, Lycium barbarum. (23) [Native.] (24) [Native. 108 OF THE DIFFERENT Sarmentosus, trailing. A creeping stem, barren of flowers, thrown out from the root for the purpose of increase, is called sarmentum orflagellum, a runner, f. 22, as in the Strawberry, Fragaria vesca, Engl. Bot. t. 1524. When leafy it is generally denomin- ated stolo, a sucker or scyon, as in Bugle, Ajuga rep- tans, t. 489, and Viola odorata, the Sweet Violet, t. 619. When the stolo has taken root, it sometimes flowers the first year, see Curt. Lond. fasc. 1. t. 63, but generally not till the following season. Rectus, straight, as in Lilium, the different species of garden Lily. Strictus, expreses only a more absolute degree of straightness. Laxus or Diffiusus, loosely spreading, has a contrary meaning, as in Bunias Cakile, Sea Rocket, Engl. Bot. t. 231, and Sedum acre, Biting Stone-crop, t. 839. Flexuosus, zigzag, forming angles alternately from right to left and from left to right, as in Smilax aspera, Ger. em. 859, and many of that genus, also Staticc reticulata, Matted Sea Lavender, Engl. Bot. t. 328. In a less degree it is not unfrequent. See Atriplex pedunculata, t. 232. Alterne ramosus, alternately branched, as Polygonum minus, t. 1043, Dianthus deltoides, t. 61, &c. Distichus, two-ranked, when the branches spread in two horizontal directions, as in the Silver Fir, Pinuspicea, Duhamel, Arb. v. 1. t. 1. (25) (25) [Also in the Hemlock tree, Pinus Canadensis.'] KINDS OF STEMS. 109 Brachiatus, brachiate, or four-ranked, when they spread in four directions, crossing each other alternately in pairs ; a very common mode of growth in shrubs hat have opposite leaves, as the Common Lilac, Syringa vulgaris. Ramosissimus, much branched, is applied to a stem re- peatedly subdivided into a great many branches with- out order, as that of an Apple- or Pear-tree, or Goose- berrybush. Prolfer, proliferous, shooting out new branches from the summits of the formw ones*, as in the Scotch Fir, Pinus sylvestris, Lambert's Pinus, t. 1. and Ly- copodium annotinum, Engl. Bot. t. 1727. This is obsolete, and seldom used. Determinate ramosus, f 23, abruptly branched, when each branch, after terminating in flowers; produces a number of fresh shoots in a circular order from just below the origin of those flowers. This term occurs frequently in the later publications of Linnaeus, par- ticularly the second Mantissa, but I know not that he has any where explained its meaning. It is exempli- fied in Azalea nudifiora, (26) Curt. Mag. 1.180, Erica Tetralix, Engl. Bot. t. 1014, many Cape Heaths, and other shrubs of the same Natural Order. (27) * Linn. Phil. Bot. sect. 82. 28. (26) [Native.] (27) \Verticillatus, a verticillate stem gives off its branches at regular intervals in whorls, like rays from a centre, as in the White Pine, Pinus strobus. Divaricatus, a divaricate stem, sends its branches obliquely downward, so as to form an obtuse angle with the stem above, and an acute angle,below.] no OF THE DllFERFM Articulatus, jointed, as in Samphire, Salicomia annua, Engl. Bot. t. 415, and more remarkably in the In- dian Figs, Cactus Tuna, &c. In shape the stem is Teres, f 32, round, as in Trollius europceus, Engl. Bot. t. 28, and Hydrangea Hortensis, Sm. Ic. Pict. t. 12. Anceps, two-edged, as Sisyrinchium striatum, Sm. Ic. Pict. t. 9. S. gramineum, (28) Curt. Mag. t. 464, and some of the genus Lathyrus, Trigonus, or Triangularis, triangular or three-edged, as Cactus triangularis, Plukenet, t. 29. f. 3. Triqueter, three-sided, is applied to a stem with 3 flat sides. Tetragonus, or Quadrangularis, square, as Lamium al- bum, White Dead-nettle, Engl. Bot. t, 768, and a multitnde of other plants. Ppntagonus, or Quinquangularis, fivesided, as Aspara- gus horridus, Cavanilles Ic. t. 136, where however the character is not well expressed. When the number of angles is either variable, or more than five, it is usual merely to describe the stem as angulosus, angular, except where the precise num- ber makes a specific difference, as in the genus Cac- tus. Alatus, f 36, winged, when the angles are extended into flat leafy borders, as Passifiora alata, Curt. Mag. t. 66, Lathyrus latifolius, Engl. Bot. (. 1108, and many others of the Pea kind, besides several Thistles, i- (28) [Native.] KINDS OE STEMS. ill as Carduus acanthoides, t. 073, palustris, t. 974, and Centaurea solstitialis, t. 243.(29) The Surface of the Stem is Glaber, smooth, opposed to all kinds of hairiness or pubescence, as in Petty Spurge, Euphorbia Peplus, Engl. Bot. t. 959, and numerous plants besides. Lcevis, smooth and even, opposed to all roughness and inequality whatever, as in the last example, and also Euonymus europaus, t. 362. Nitidus, polished, smooth and shining, as Charophyllum sylvestre, t. 752. Viscidus, viscid, covered with a clammy juice, as Lych- nis Viscaria, t. 788. Verrucosus, warty, like Euonymus verrucosus, Jacq. Fl. Austriaca, t. 49, and Malpighia volubilis, Curt. Mag. t. 809. Papillosus, papillose, covered with soft tubercles, as the Ice plant, Mesembryanthemum crystallinum. Dill. Elth. t. 180. Scaler, rough to the touch from any little rigid inequal- ities, opposed to lavis, as Caucalis Anthriscus, Engl. Bot. t. 987, Centaurea nigra, t. 278, and Stellaria holostea, £.511. Hispidus, bristly, as Borage, Borago officinalis, t. 36, and Char a hispida, t. 463. Hirtus, or Pilosus, hairy, as Salviapratensis, t. 153, and Cerastium.vlpinum, t. 472. (29) [Also the Spear Thistle, Carduus ovCnicus lanceolatus, and Cotton Thistle, Onoftord«n Acanthium.~] 112 OF THE SURFACE OF THE STEM. Tomentosus, downy, as Geranium rotundifolium, t. 157, very soft to the touch. Villosus, shaggy, as Cineraria integrifolia, t. 152. Lariatus, woolly, as Verbascum pulverulentum, t. 487, V. Thapsus, (30) t. 549, and Santolina maritima, t. 141. Incanus, hoary, as Wormwood, Artemisia Absinthium, t. 1230, and Atrip lex portulacoides, t. 261, in the for- mer case from close silky nairs, in the latter from a kind of scaly mealiness. Glaucus, clothed with fine sea-green mealiness which easily rubs off, as Chlora perforata, t. 60, and Pul monaria maritima, t. 368.(31) Striatus, striated, marked with fine parallel lines, as Oenanthe fistulosa, t. 363. Sulcatus, furrowed, with deeper lines, as Smyrnium Olusatrum, t. 230. Maculatus, spotted, as Hemlock, Conium maculatum, t. 1191. (32) The spines and prickles of the stem will be explained hereafter. Internally the stem is either solidus, solid, as that of Inula crithmoides, t. 68, and numerous others ; or ca- vus, hollow, as in Cineraria palustris, t. 151, as well as Hemlock, and many umbelliferous plants besides. (33) (30) [Common Mullein.] (31) [Likewise Rubus occidentalis, the common Black Raspberry.] (32) [Native.] (33) [Some botanists use the terms solidus, solid; inanis,pithy, andjistulosus, fistulous or hollow.] OF STEMS 115 Plants destitute of a stem are called acaules, stemless, as Neottia acaulis, Exot. Bot. t. 105, and Carduus acaulis, Engl. Bot. t. 161. Such plants, when they be- long to a genus or family generally furnished with stems, as in these instances and Carlina acaulis, Camer. Epit. 428, are liable from occasional luxuriance to ac- quire some degree of stem, but seldom otherwise. Pin- guicula, Engl. Bot. t. 7fi and 145, is a genus invariably stemless, while Primula, t. 4, 5, 6 and 513, is much less truly so. The term acaulis however must never be too rigidly understood, for logical precision is rarely appli- A cable to natural productions. Caulis fasciculatus, a clustered stem, is a disease or accident, in which several branches or stems are united longitudinally into a flat broad figure,, crowded with leaves or flowers at the extremity. It occurs in the Ash, several species of Daphne, Ranunculus, Antirrhinum, &c. In a kind ofPisum, called the Top-knot Pea, it is a permanent variety propagated by seed. 2. Culmus. A Straw or Culm, is the peculiar Stem of the Grasses, Rushes, and plants nearly allied to them. It bears both leaves and flowers, and its na- ture is more easily understood than defined. Many botanists have thought this term superfluous. The Culm is occasionally Enodis, without joints, as in our common Rushes, Juncus conglomeratus, Engl. Bot. t. 835, and effu- sus, t. 836 ; (34) (34) [Bulrush in the New England states. This name is al- so applied to Scirftus lacustris, a much larger plant.] P 114 OF THE STALK. Articulatus, jointed, as in Agrostis alba, t. 1189, Aira canescens, t. 1190, Avena strigosa, t. 1266, and most other grasses ; Geniculatus, bent like the knee, as Alopecurus genicu* latus, t. 1250. It is eitherp solid t or hollow,m round t or triangular, rough or smooth, sometimes hairy or downy, scarcely woolly. I know of no instance of sueh a scaly culm as Linnasus has figured in his Philosophia Botanica, t. 4.f. Ill, nor can I conceive what he had in view. 3. Scapus. A Stalk, springs from the Root, and bears the flowers and fruit, but not the leaves. Pri- mula vulgaris, the Primrose, Engl. Bot. t. 4, and P. veris, the Cowslip, t. 5, are examples of it. In the former the stalk is simple and single-flowered; in the latter subdivided and many-flowered. It is either naked, as in Narcissus, Engl. Bot. t. 17, or scaly, as in Tussilago Farfara, t. 429. In others of this last genus, t. 430 and 431, the scales become leafy, and render the Scapus a proper Caulis.{35) The Stalk is spiral in Cyclamen, Engl. Bot. t. 548' and Valisneria spiralis, a wonderful plant, whose history will be detailed hereafter. Linnaeus believed* that a plant could not be increased by its Scapusy which in general is correct, but we have (35) [Plants furnished with the stalk, or, as it is more fre- quently rendered, scafie ; come under the head of Acaules, or stemless plants, p. 112. Thus the Daffodil, Dandelion, and many of the Violets are stemless plants.] * MSS. in Phil. Bot. 40. OF THE FLOWER-STALK. 116 already recorded an exception, p. 101, in Lachenalia tri- color. The same great author has observed* that " a Scapus is only a species of Pedunculus." The term might therefore be spared, were it not found very com- modious in constructing neat specific definitions of plants. If abolished, Pedunculus radicalis, a radical flower-stalk, should be substituted in its room. 4. Pendunculus, the Flower-stalk, springs from the stem, and bears the flowers and fruit, not the leaves. Pedicellus, a partial flower-stalk, is the ultimate subdi- vision of a general one, as in the Cowslip, and Sax- ifraga umbrosa, Engl. Bot. t. 663. The Flower-stalk is t Caulinus, cauline, when it grows immediately out of the main stem, especially of a tree, as in Averrhoa Billimbi, Rumph Amboin, v. 1. t. 36, the Indian substitute for our green gooseberries. Rameus, growing out of a main branch, as in Averr- hoa Carambola, ibid. t. 35, and Eugenia malaccen- sis, Exot. Bot. t. 61. Axillaris, axillary, growing either from the bosom of a leaf, that is, between it and the stem, as Anchusa sempervirens, Engl. Bot. t. 45, and Campanula Trachelium, t. 12 ,• or between a branch and the stem, as Ruppia maritima, t. 136.(36) Oppositifolius, opposite to a leaf, as Geranium pyreniac- um, t. 405, G. molle, t. 778, and Sium angustifolium, t. 139. * MSS. in Phil. Bat. 40. (56) [Native.] 116 OF THE FLOWER-STALK. Internodis, proceeding from the intermediate part of a branch between two leaves, as in Ehretia internodis, DHeritier Stirp. t. 24, Solanum carolinense, Dill. Hort. Elth. t. 259, and indicum, t. 260 ; but this mode of insertion is rare. Gemmaceus, growing out of a leaf-bud, as the Barber- ry, Berberis vulgaris, Engl. Bot. t. 49.(37) Terminalis, terminal, when it terminates a stem or branch, as Tulipa sylvestris, t 63, and Centaurea Sea- biosa, t, 56. Lateralis, lateral, when situated on the side of a stem or branch, as Erica vagans, t. 3. Solitarius, solitary, either single on a plant, as in Rubus Chamaemorus, t. 716, or only one in the same place, as in Antirrhinum spurium, t. 691, and many com- mon plants. Aggregati Pedunculi, clustered flower-stalks, when sev- eral grow together, as in Verbascum nigrum, t. 59. Sparsi, scattered, dispersed irregularly over the plant or branches, as Linum perenne, t. 40, and Ranuncu- lus sceleratus, t. 681,(38) Unifiori, bifiori, trifiori, &c. bearing one, two, three, or more flowers, of which examples are needless. Multifiori, many-flowered, as Daphne Laureola, t. 119. When there is no Flower-stalk, the flowers are said to be Sessiles, sessile, as in Centaurea Calcitrapa, t. 125, and the Dodders, t. 55 and 378. The subject of inflorescence, or particular modes of flowering, will be explained in a future chapter. (37) [Native.] (38) [Native.] OF THE FLOWER-STALK. 117 5. Petiolus. The Footstalk, or Leafstalk. This term is applied exclusively to the stalk of a leaf, which is either simple, as in Ranunculus parvifiorus, Engl. Bot. t. 120, Sium angustifolium, t. 139, and all sim- ple leaves ; or compound, as Coriandrum sativum, t. 67, and Fumaria claviculata, t. 103. In the latter the footstalks end in tendrils, and are called Petioli cirriferi.{39) This part is commonly channelled on the upper side. Sometimes it is greatly dilated and concave at the base, as in Angelica sylvestris, t. 1128. The Footstalk bears the Flower-stalk in Turnera ulmifolia, Linn. Hort. Cliff, t. 10. Menyanthes indica, Curt. Mag. t. 658, and perhaps Epimedium alpinum, Engl. Bot. t. 438. 6. Frons. A frond. In this the stem, leaf and fructification are united, or, in other words, the flow- ers and fruit are produced from the leaf itself, as in the Fern tribe, Scolopendrium vulgare, Engl. Bot. t. 1150, Polypodium vulgare, t. 1149, Aspidium, t. (39) [The Petiole or leaf stalk may be Teres, round, as in the common Hollyhock. Semiteres, half round, as in the yellow Water Lily, Nym- fihaa advena. Comfiressus, flattened, as in the Lombardy Poplar, Poftulus dilatata, also P. grandidentata, and others. , Alatus, winged, or furnished on each side with a leafy appen- dage, as in the Orange tree, also in Rhus Coftallinum, called Copal, Dwarf, or White Sumach. Cirrhifer, bearing tendrils, as in the Fumaria above, and the common Pea. Scandens, climbing, performing the office of a tendril, as in the C'/- ■?>) a tin Virginiana.l 118 OF 1HE FROND. 1458—1461, Osmunda regalis, t. 209, &c.(40) It is also applied to the Lichin tribe, and others, in which the whole plant is either a crustaceous or a leafy sub- stance, from which the fructification immediately pro- ceeds. Linnaeus considered Palm-trees as fronds, so far correctly as that they have not the proper stem of a tree, see p. 59; but they are rather perhaps herbs whose stalks bear the fructification. It must however be observed that the deposition of wood in ferns, takes place exactly as in palms. The term frond is now used in the class Crypto- gamia only. 7. Stipes, Stipe*, is the stem of a frond, which in ferns is commonly scaly. See the plates cited in the last section. The term is likewise applied to the stalk of a Fungus, as the Common Mushroom, Aga- ricus campestris, Sowerby's Fungi> t. 305. (40) [Many Ferns, of the three last mentioned genera, are found in the United States.] * Martyn, Language of Botany. t H9 ] CHAPTER XIV. OF BUDS. Gemma, a Bud, contains the rudiments of a plant, or of part of a plant, for a while in a latent state, till the time of the year and other circumstances favour their evolu- tion. In the hud therefore the vital principle is dor- mant, and its excitability is accumulated. The closest analogy exists between buds and bulbs ; and indeed the Dentaria bulbifera, Engl. Bot. t. 309, Lilium bulbifer- um, Jacq. Fl. Austr. t. 226, and Gerarde emac. 193, with other similar plants, as mentioned p. 100, almost prove their identity. Buds of trees or shrubs, destined for cold countries, are formed in the course of the summer in the bosoms of their leaves, and are generally solitary; but in the Blue-berried Honeysuckle, Lonicera cterulea, Jacq. Fl. Austr. append, t. 17, they grow one under another for three successive seasons,/^ 24. The buds of the Plane- tree, Platanus, Du Hamel Arb. v. 2. 171, are concealed in the footstalk, which must be removed before they can be seen, and which they force off by their increase; so that no plant can have more truly and necessarily de- ciduous leaves than the Plane. Shrubs in general have no buds, neither have the trees of hot climates. Lin- naeus once thought the presence of buds might distin- guish a tree from a shrub, but he was soon convinced of there being no real limits between them. UO OF THE BID The situation of buds is necessarily like that of the leaves, alternate, opposite, &c. Trees with opposite leaves have three buds, those with alternate ones a sol- itary bud, at the top of each branch. Du Hamel. Buds are various in their forms, but very uniform in the same species or even genus. They consist of scales closely enveloping each other, and enfolding the embryo plant or branch. Externally they have often an addi- tional guard, of gum, resin or woolliness, against wet and cold. The Horse Cnesnut, JEsculus Hippocastanum, now so.common with us, though, as I have learnt from Mr. Hawkins*, a native of Mount Pindus in Arcadia, is a fine example of large and wellformed buds,yi 25 ; and some of the American Walnuts are still more re- markable. It has been ahead)7 remarked, p. 84, that buds resist cold only till they begin to grow : hence, according to the nature and earliness of their buds, plants differ in their powers of bearing a severe or variable climate. Grew is elaborate on the forms of buds, and the ar- rangement of the spots apparent within them when cut transversely, which indicate the number and situation of their vessels. It was the character of this excellent man to observe every thing, without reference to any theory, and his book is a storehouse of facts relating to vegetation. Loefling, a favourite pupil of Linnaeus, wrote, under the eye of his great-teacher, an essay on this subject, published in the Amanitates Academics, v. * See a note on this subject, which Mr. R. P. Knight has honoured with a pla&e in the second edition of his poem on Landscape. OF BUDS. tfl % in which the various forms of buds, and the different disposition of the leaves within them, are illustrated by numerous examples. The Abbe de Ramatuelle had taken up this subject with great zeal at Paris, about twenty years ago, but the result of his inquiries has not reached me. Dr. Darwin, Phytologia, sect. 9, has many acute ob- servations on the physiology of buds, but he appears to draw the analogy too closely between them and the em- bryo of a seed, or the chick in the egg. By buds indeed, as we well know, plants are propagated, and in that sense each bud is a separate being, or a young plant in itself; but such propagation is only the extension of an individual, and not a reproduction of the species as by seed. Accordingly, all plants increased by buds, euttings, layers or roots, retain precisely the peculiar qualities of the individual to which they owe their origin. If those qualities differ from what are common to the species, sufficiently to constitute what is called a varie- ty, that variety is perpetuated through all the progeny thus obtained. This fact is exemplified in a thousand instances, none more notorious than the different kinds of Apples, all which are varieties of the common Crab,, Pyrus Malus, Engl. Bot. t. 179 ; and I cannot but as- sent to Mr. Knight's opinion, that each individual thus propagated has only a determinate existence, in some cases longer, in others shorter ; from which cause many valuable varieties of apples and pears, known in former times, are now worn out, and others are dwindling away before our eyes. New varieties of Cape Geraniums, iafc OF BL'DS. raised from seed in our greenhouses, are of still shorter duration, and can be preserved by cuttings for a few successive seasons only ; yet several of these stand in our boranic works, with all the importance of real spe- cies. Gardeners know how many of the most hardy perennial herbs require to be frequently renewed from seed to exist in full vigour ; and though others appear, to our confined experience, unlimited in that respect, we have many reasons to believe they are not so. Pro- pagation by seeds is therefore the only true reproduc- tion of plants, by which each species remains distinct, and all variations are effaced ; for though new varieties may arise among a great number of seedling plants, it does not appear that such varieties owe their peculiari- ties to any that may have existed in the parent plants. How propagation by seed is accomplished will be ex- plained in a future chapter, as well as the causes of some varieties produced by that means. Mr. Knight, in the Philosophical Transactions for 1805, has shown that buds originate from the alburnum, as might indeed be expected. The trunks and branch- es of trees, and the knobs of genuine tuberous roots, like the potatoe, are studded with them ; in which respect, as Professor Willdenow judiciously observes, Princi- ples of Botany, p. 15, such roots essentially differ from bulbous ones, which last are themselves simple buds, and produce their shoots, as well as their offsets, either from the centre or from the base. The contents of buds are different, even in different species of the same genus, as Willows. The buds of some produce leaves only, others flowers; while in oth- ©F BUDS. 123 er species the same bud bears both leaves and flowers. Different causes, depending on the soil or situation, seem in one case to generate leaf-buds, in another flower- buds. Thus the Solandra grand-flora, Tr. of Linn. Soc. v. 6. 99. t. 6, a Jamaica shrub, was for a number of years cultivated in the English stoves, and propaga- ted extensively by cuttings, each plant growing many feet in length every season, from abundance of moisture and nourishment, without showing any signs of fructifi- cation. At length a pot of the Solandra was accidentally left without water in the dry stove at Kew ; and in con- sequence of this unintentional neglect, the luxuriant growth of its branches was greatly checked, and a flower came forth at the extremity of each. By a similar mode of treatment the same effect has since frequently been produced. Several plants, especially with bulbous roots, which blossom abundantly in their native soils, have hitherto defied all the art of our gardeners to produce this desirable effect; yet future experience may possibly place it within our reach by some very simple means. In general, whatever checks the luxuriant production of leaf-buds, favours the formation of flowers and seeds. That variety, or perhaps species, of the Orange Lily, Lilium bulbiferum, which is most prolific in buds, sel- dom forms seeds, or even those organs of the flower necessary to their perfection. So likewise the seeds of Mints, a tribe of plants which increase excessively by roots, have hardly been detected by any botanist ; and it is asserted by Doody in Ray's Synopsis, that when the elegant little Ornithopus perpusillus, Engl. Bot. t. 369, does not produce pods, it propagates itself by the grains or tubercles of its root, though in general the root is annual. t 124 ] CHAPTER XV. OF LEAVES, THEIR SITUATIONS, INSERTIONS, SURFACES, AND VARIOUS FORMS. Folium, the Leaf, is a very general, but not universal, organ of vegetables, of an expanded form, presenting a much greater surface to the atmosphere than all the other parts of the plant together. Its colour is almost universally green, its internal substance pulpy and vas- cular, sometimes very succulent, and its upper and un- der surfaces commonly differ in hue, as well as in kind or degree of roughness. Leaves are eminently ornamental to plants from their pleasing colour, and the infinite variety as well as ele- gance of their forms. Their many ceconomical uses to mankind, and the importance they hold in the scale of nature as furnishing food to the brute creation, are sub- jects foreign to our present purpose, and need not here be insisted upon. Their essential importance to the plant which bears them, and the curious functions by which they contribute to its health and increase, will presently be detailed at length. We shall first explain their different situations, insertions, forms, and surfaces, which are of the greatest possible use in systematical botany. The leaves are wanting in many plants, called for that reason plant a aphylla, as Salicornia, (41) Engl Bot. t. 415, and 1691, Stapelia variegata, Curt. Mag, (41) [Samphire or Glasswort.] SITUATION AND POSITION OF LEAVES. 125 t. 26, glandulflora, Exot. Bot. t. 71, and all the species of that genus. In such cases the surface of the stem must perform all their necessary functions. 1. With respect to Situation and Position, Folia radicalia, radical leaves, are such as spring from the root, like those of the Cowslip, Engl. Bot. t. 5, and Anemone Pulsatilla, t. 51. Caulina, stem-leaves, grow on the stem as in Paris quadrifolia, t. 7, Polemonium aeruleum, t. 14, &c. Ramea, branch-leaves, sometimes differ from those of the main stem, and then require to be distinguished from them, as Melampyrum arvense, t. 53. Alterna, f. 21, alternate leaves, stand solitarily on the stem or branches, spreading in different directions, as those of Borage, t. 36, and innumerable other plants. Sparsa,f. 19, scattered irregularly, as in Genista tincto- ria, t. 44, Lil.um chalcedonicum, Curt. Mag. t. 30, and bulbiferum, t. 36. Opposita, opposite to each other, as Saxifraga opposite folia, Engl. Bot. t. 9, Ballota nigra, t. 46, &c. Conferta, clustered, or crowded together, as those of Trientalis europcea, t. 15.(42) Bina, only two upon a plant or stem, as in the Snow- drop, Galanthus nivalis, t. 19, Scilla bifolia, t. 24, and Convallaria majalis, t. 1035.(43) Terna, three together, as Verbena triphylla. Curt. Mag. (42) [Chickweed wintergreen.l (43) [Lily of the valley.] m 1-6 SITUATION" AND POSITION OF LEAVES. t. 367. The plants of Chili and Peru seem particu- larly disposed to this arrangement of their leaves. Quaterna, quina, &c. when 4, 5, or more are so situat- ed, as in various species of Heath, Erica. Verticillata, whorled, is used to express several leaves growing in a circle round the stem, without a refer- ence to their precise number, as in Asperula cynan- chica, Engl: Bot. t. 33, and odorata, t. 755, which with the genus Galium, and some others, are for this reason called stella/ar, star-leaved plants. Whorled leaves are also found in Hippuris vulgaris, t. 763, and many besides.(44) Fasciculata,f 26, tufted, as in the Larch, Pinus, Larix, Lamb, Pin. t. 35, the Cedar, and some others of that genus. Imbricata,fi 27, imbricated, like tiles upon a house, as in the common Ling, Erica vulgaris, Eiigl. Bot. t. 1013, and Euphorbia par alia, t. 195. Decussata,f.28, decussated, in pairs alternately crossing each other, as Veronica decussata, Curt. Mag. t. 242, and Melaleuca thymifolia, Exot. Bot. t. 36. Disticha,f. 29, two-ranked, spreading in two directions, and yet not regularly opposite at their insertion, as Pinus canadensis, Lamb.Pin. t. 32, and the Ye\v,Tax- us baccata, Engl. Bot. t. 746. Secunda, f. 30, unilateral, or leaning all towards one side, as Convallaria multifiora, t. 279.(45) (44) [Examples of whorled leaves are found in the Lilies, Lilium Canadense and Philadelfthicum.~\ (45) [Many flowered Solomon's seal.] SITUATION AND POSITION OF LEAVES. 12? Adpressa, close-pressed to the stem, as Xeranthemum sesamoides, Curt. Mag. t. 425. Verticalia, perpendicular, both sides at right angles with the horizon, as Lactuca Scariola, Engl. Bot. r.268. Erecta, upright, forming a very acute angle with the stem, as Juncus articulatus, t. 238. Patentia, spreading, forming a moderately acute an- gle with the stem or branch, as Atriplex portulaco- ides, t. 261. Horizontalia, horizontal, or patentissima, spreading in the greatest possible degree, as Gentiana campestris, t. 237. Reclinata, inclining downward, as Leonurus Cardiaca, t. 286.(46) Recurva, or refiexa, curved backward, as Erica retor- ta, Curt. Mag. t. 362. Incurva, or infiexa, curved inward, as Erica empetri- folia, t. 447. Obliqua, twisted, so that one part of each leaf is verti- cal, the other horizontal, as Fritillaria obliqua, t. 857, and some of the large Protece. Resupinata, reversed, when the upper surface is turn- ed downward, as Pharus latifolius, Browne's Jamai- ca, t. 38. Linn. Mss.t and Alstrameria pelegrina, Curt. Mag. t. 139. Depressa, radical leaves pressed close to the ground, as Plantago media, EngL Bot. t. 1559, and P. Coronopus, t. 892. The same term applied t© (46) [Common Motherwort] 123 INSERTION OF LEAVES. stem-leaves, expresses their shape only, as being vertically flattened, in opposition to compressa. Natantia, floating, on the surface of the water, as Nymphcea lutea, t. 159, and alba, t. 160, (47) and Potamogeton natans, (48) and many water plants. Demersa, immersa, or submersa, plunged under wa- ter, as Potamogeton perfoliatum, t. 168, Hottonia palustris, (49) t. 364, Lobelia Dortmanna, t. 140, and the lower leaves of Ranunculus aquatilis, t. 101, while its upper are folia natantia. Emersa, raised above the water, as the upper leaves, accompanying the flowers, of Myriophyllum verti- cilatum, t. 218, (50) while its lower ones are de- mersa. 2. By Insertion is meant the mode in which one part of a plant is connected with another. Folia petiolata, leaves on footstalks, are such as are furnished with that organ, whether long or short, simple or compound, as Verbascum nigrum, Engl. Bot. t. 59, Thalictrum minus, t. 11, alpinum, t. 262, &c. Peltata, f 31, peltate, when the footstalk is inserted into the middle of the leaf, like the arm of a man holding a shield, as in the Common Nasturtium, Tropceolum majus, Curt. Mag. t. 23, Drosera pel- (47) [So the American Water Lilies, Nymfihaa advena and od- 9rata.~\ (48) [Pondweed.] (49) [Water Feather, or Water Violet. Native, as also the next.] (50) [Whorled Water Milfoil.] INSERTION OF LEAVES. 159 tata, Exot. Bot. t. 41, Cotyledon Umbilicus, Engl. Bot. t. 325, Hydrocotyle vulgaris, (51) t. 751, and the noble Cyamus Nelumbo, Exot. Bot. t. 31, 32. Sessilia, sessile, a re such as spring immediately from the stem, branch or root, without any footstalk, as in Anchusa sempervirens, Engl. Bot. t. 45, and Pingui- cula vulgaris, t. 70. (52) Amplexicaulia, f 32, clasping the stem with their base, as the upper leaves of Glaucium luteum, t. 8, Gentia- na campestris, t. 237, and Humea elegans, Exot. Bot. t. 1. (53) Connata,f. 17, connate, united at their base, as Chlora perfoliata, Engl. Bot. t. 60, whose leaves are conna- to-perfoliata. Perfoliata, f. 33, perfoliate, when the stem runs through the leaf, as Bupleurum rotundifolium, t. 99, and the . Uvularia, Exot. Bot. t. 49, 50, 51.(54) Vaginantia, f 34, sheathing the stem or each other, as in most grasses ; see Phleum Alpinum, Engl. Bot. t. (51) [Penny wort.] (52) [Sessile leaves are very common, as in many of the ge- nus Solidago, Golden Rod ; &c] ( 53) [Clasping leaves are exemplified in many of the Star- worts or Asters, as in Aster JVbvte Anglia and amftlexicaulis."] (54) [The veins or nerves of a leaf will generally determine whether it be a single, perfoliate leaf, as in Uvularia fierfoliata ; or double and connate, as oscurs in different degrees in the up- per leaves of the Trumpet Honeysuckle, Lonicera semftervivens, in Fever Wort, Triosteum fterfoliatum, and in Rudbeckia Amftlex- ifolia, where the connexion is slight.! U 130 FORMS OF LEAVES. 519, and Arundo arenaria, t. 520. The same char- acter is found in many of the Qrchis tribe, as Satyri- um albidum, t, 505. Equitantia, f 35, equitant, disposed in two opposite rows and clasping each other by their compressed base, as in Narthecium ossifragum, t. 535, and the genus Iris ; also Witsenia corymbosa, Exot. Bot. t* 68, and Dilatris corymbosa, t. 16. Decurrentia, f. 36, decurrent, running down the stem or branch in a leafy border or wing, as Onopordum Acan- thium, (55) Engl. Bot. t. 977, Carduus tenuifiorus, t. 412, and many other Thistles, also the Great Mullein, Verbascum Thapsus, t. 549, and Comfrey, Symphy- tum officinale, t. 817. Florifera, f. 37, flower-bearing, when flowers grow out of the disk or margin of any leaf, as in Ruscus aculea- tus, I. 560, Xylophylla latifolia, and X.falcata, Andr. Repos. t. 331. This is equivalent to a frond in the class Cryptogamia ; see p. 117. 3. With regard to form, Leaves are either simplicia, simple, like those of Grasses, Orchises, Lilies, and many other plants, as Ballota nigra, Engl. Bot. t. 46, and Berberis vulgaris, t. 49 ; or composita, com- pound, as in most Umbelliferous plants, Parsley, Hemlock, &c. ; also Roses, Engl. Bot. t. 990—992. In compound leaves, the footstalk is either simple, as in the instances last quoted, and Sium angustifolium, t. 139 ; or compound, as those of Selinum palustre, t. 229, and Thalictrum majus, t. 611.—In simple (55) [Cotton Thistle.] I 0RMS OF LEAVES. 131 leaves the footstalk, if present, must of course be simple, while in compound ones it must always be present, though not always subdivided. Simple Leaves are either Integra, undivided, as those of Grasses and Orchises ; or lobata, lobed, like the Vine, the Thistle, most kinds of Cranesbill, as Gera- nium pratense, Engl. Bot. t. 404, &c. Leaves are frequently undivided and lobed on the same plant, as the Hop, Engl. Bot. t. 427.(55.) 4. The following are the most remarkable forms of Simple Leaves, considering their outline only. Orbiculatum, f. 38, a circular or orbicular leaf, whose length and breadth are equal, and the circumference an even circular line. Precise examples of this are scarcely to be found. Some species of Piper ap- proach it, and the leaf of Hedysarum styracifolium is perfectly orbicular, except a notch at the base. Subrotundum,f. 39, roundish, as Pyrola, (56) Engl. Bot. t. 146, 158 and 213, and many other plants. Ovatum,f 40, ovate, of the shape of an egg cut length- wise, the base being rounded and broader than the extremity, a very common form of leaves, as Urtica pilulfera, t, 148, and Vinca major, t. 514. Obovatum, f 41, obovate, of the same figure with the broader end uppermost, as those of the Primrose, t. 4, and the Daisy, t. 424.(57) Linnaeus at first used the words obverse ovatum. (55) [This is the case in the Sassafras tree, Laurus sassafras.~\ (56) [The Pyrola rotundifolia, or Winter green, is very cam •:!'.m in the United States.] 57) [And the leaves of Clethra Alnisolia.^ 132 FORMS OF LEAVES. Ellipticum, f. 42, or ovale, elliptical or oval, of a similar form to the foregoing, but of equal breadth at each end, as in the Lily of the Valley, and other Convalla- rice, t. 1035, 279 and 280. * Oblongum, oblong, three or four times longer than broad. This term is used with great latitude, and serves chiefly in a specific character to contrast a leaf which has a variable, or not very decided, form, with others that are precisely round, ovate, linear, &c. Spatulatum,f. 43, spatulate, of a roundish figure taper- ing into an oblong base, as in Silene Otites, Fl. Brit, Engl. Bot. t. 85. Cuneiforme, f 44, wedge-shaped, broad and abrupt at the summit, and tapering down to the base, as in Saxifraga cuneifolia.(58) Lanceolatum,f. 45, lanceolate, of a narrow oblong form, tapering towards each end, very comon, as Tulipa sylvestris, Engl. Bot. t. 63, Lithospermum purpuro- caruleum, t. 117, Plantago lanccolata, (59) t. 507, many Willows, &c. Lineare,f 46, linear, narrow with parallel sides, as those of most Grasses ; also Gentiana Pneumonanthe, t, 20, and Narcissus Pseudo-jiarcissus, t. 17. Acerosum, f. 47, needle-shaped, linear and evergreen, generally acute and rigid, as in the Fir, Pinus, Juni- per, Juniperus communis, t. 1100, and Yew, Taxus baccata, t. 746. Linnaeus observes, Phil. Bot. 219, that this kind of leaf has, for the most part, a joint at its union with the branch. (58) [Also in Purslane, Portulacca okracea.l (59^ [Ribwort, or Field Plantain.] FORMS OF LEAVES. 133 Triangulare,fi 48, triangular, having three prominent angles, without any reference to their measurement or direction, as in the genus Chenopodium, (60) Cochlearia danica, t. 696, and some leaves of the Ivy. Quadrangularef. 49, with four angles, as the Tulip-tree, Liriodendrum tulipifera, (61) Sm. Ihs. of Georgia, t. 102. Curt. Mag. t. 275. Quinquangulare, f 19, with five angles, as some Ivy leaves, &c. Deltoides,f 50, trowel-shaped or deltoid, having three angles, of which the terminal one is much further from the base than the lateral ones, as Chenopodium Bonus-Henricus, Engl. Bot. t. 1033, and some leaves of Cochlearia danica. A wrong figure is quoted for this in Philosophia Botanica, which has caused much confusion. Rhombeum, f 51, rhomboid, or diamond-shaped, ap-* proaching to a square, as Chenopodium olidum, t. 1034, Trapa natans, Camer. Epit. 715, and Trillium erectum, Curt. Mag. t. 470.(62) Remforme,f. 52, kidney-shaped, a short, broad, round- ish leaf, whose base is hollowed out, as Asarum euro- pium, Engl. Bot. t. 1083, and Sibthorpia europxa, t. 649.(63) Cordatum, f 53, heart-shaped, according to the vulgar idea of a heart ; that is, ovate hollowed out at the base, as Tamuscommunis, t. 91.(64) f60) [Goosefoot or Hogweed.] t (61) [One of the most elegant of North American trees.] (62) [Native.] 63) [Likewise Glecoma hederacea, Ground Ivy.] (64) [Also, the common annual Sunflower, many Violets, As- t/."\s. &c] Hi FORMS OF LEAVES. Lunulatum, f 54, crescent-shaped, like a half-moon, whether the points are directed towards the stalk, or from it, as Passifiora, lunata, Sm. Ic. Pict. t. 1. Sagittatum, f 55, arrow-shaped, triangular, hollowed out very much at the base, as Sagittaria sagittifolia, (64) Engl. Bot. t. 84, and Rumex Acetosa, t. 127. Sometimes the posterior angles are cut off, as in Con- volvulus sepium, t. 313.(65) Hastatum, f 56, halberd-shaped, triangular, hollowed out at the base and sides, but with spreading lobes, as Rumex Acetosella,(66) t. 1674, Antirrhinum Ela- tine, t. 692, and the upper leaves of Solanum Dulca- mara, (67) t. 565. Panduriforme,f 57, fiddle-shaped, oblong, broad at the two extremities and contracted in the middle, as the Fiddle Dock, Rumex pulcher, t. 1576. Runcinatum, f 58, runcinate, or lion-toothed, cut into several transverse,acute segments,pQintingbackwards, as the Dandelion, Leontodon Taraxacum, t. 510. Lyratum,f 59, lyrate, of lyre-shaped, cut into several transverse segments, gradually larger towards the ex- tremity of the leaf, which is rounded, as Erysimum Barbarea, t. 443. F'issum^. 60, cloven, when the margins of the fissures and segments are straight, as in the Gingko-tree, Salisburia adiantifolia. Bifidum, trifidum, multifidum, &c. express the number of the segments. Lobatum, f. 61, lobed, when the margins of the seg- (64) [Arrow head.] (65) [Bindweed.] (66) [Sheep sorel.] (67) [Bitter sweet.] FORMS OF LEAVES. 135 ments are -rounded, as in Anemone Hepatica, Curt. Mag. t. 10. (68) Bilobum, trilobum, &c, according to the number of the lobes. Sinuatum,f. 62, sinuated, cut into rounded or wide Openings, as Statice sinuata, t. 71, and Virgilia heli- oides, Exot. Bot. t. 37. ., Partitum, f 63, deeply divided, nearly to the base, as Hetleborus viridis, Engl. Bot. t. 200. Bipartitum, tripartitum, multipartitum, according to the number of the divisions. Laciniatum, f 64, laciniated, cut into numerous irreg- ular portions, as Ranunculus parvifiorus. t. 120, and Geranium columbinum, t. 259. Incisum, and Dissectum, cut, are nearly synonymous with the last. It is remarked by Linnaeus that aquatic plants have their lower, and mountainous ones their upper, leaves most divided, by which they better resist the action of the stream in one case, and of wind in the other. Probably these actions are in some measure the caus- es of such configurations. Palmatum,f 65, palmate, cut into several oblong, near- ly equal segments, about half way, or rather more, towards the base, leaving an entire space like the palm of the hand, as Passiftora ceerulea, Curt. Mag. t. 28. Pinnatifidum,f 66, pinnatifid, cut transversely into sev- eral oblong parallel segments, as in Ipomopsis, Exot. (68) [Early Anemone or Liverwort. Native.] 186 TERMINATIONS OF LEA\£^. Bot. t. 13, 14, Bunias Cakile. Engl. Bot. t. 231, Le- pidium didymum, t. 248, petraum, t. Ill, and Myri- ophyllum verticillatum, t. 218. Bipinnatifldum, f 67, doubly pinnatifid, as Papaver Argemone, t. 64^»and Eriocalia major, Exot. Bot t. 78. (69) Pectinatum,f 68, pectinate, is a pinnatifid leaf, whose segments are remarkably narrow and parallel, like the teeth of a comb, as the lower leaves of Myriophyllum verticillatum, and those of Hottonia palustris, Engl. Bot. t. 364. Innequale, f 69, unequal, sometimes called oblique, when the two halves of the leaf are unequal in dimen- sions, and their bases not parallel, as in Eucalyptus resinifera, Exot. Bot. t. 84, and most of that genus, as well as of Begonia. 5. The Terminations of leaves are various. Folium truncatum,f. 49, an abrupt leaf, has the extrem- ity cut off, as it were, by a transverse line, as Lirio- dendrum tulipifera, Curt. Mag. t. 275. Prcemorsum, f 70, jagged-pointed, very blunt, with various irregular notches, as in Dr. Swartz's genus. Aerides, comprehended under the Epidendrum of Lin- naeus. See E. tessellatum, Roxb. PI. of Coromandel, t. 42, and pramorsum, t.4>3. Retusum,f 71, retuse, ending in a broad shallow notch, as Rumex digynus, Engl. Bot. t. 910. i (69) Leaves singly and doubly pinnatifid, are found in the weeds called Roman Wormwood or Hogweed, Ambrosia, elatior, /taniculata, &C TERMINATIONS OF LEAVES. 137 Emarginatum,f 72, emarginate, or nicked, having a small acute notch at the summit, as the Bladder Sen- na, Colutea arborescens, Curt. Mag. £.81. Ohtusum,f. 39, blunt, terminating in a segment of a circle, as the Primrose, Engl. Bot. t. 4, Snowdrop, t. 19, Hypericum quadrangulum, t. 370, and Linum catharticum, t. 382. Acutum,f. 51, sharp, ending in an acute angle, which is common to a great variety of plants, as Ladies' Slipper, t. 1, Campanula Trachelium t. 12, and Lin- um angustifolium, t. 381. Acuminatum, f. 73, pointed, having a taper or awlshap- ed point, as Arundo Phragmites, t. *01, and Scirpus maritimus, L 542.(70) Obtusum cum acumine,f 74, blunt with a small point, as Statice Limonium, t. 102.(71) Mucronatum or Cuspidatum,f 75, sharppointed, tipped with a rigid spine, as in the Thistles, t. 107, t. 386, - Sec, Ruscus aculeatus, t. 560, and Melaleuca nodosa, Exot. Bot. t. 35. Cirrosum., f. 76, cirrose, tipped with a tendril, as in Gloriosa superba, Andr. Repos. t. 129. 6. The different Margins of Leaves, are characterized as follows. Folium integerrimum,f 39, an entire leaf, as in the Or- chis and Lily tribe, as well as Polygala vulgaris, Engl. Bot. t. 76, Daphne Laureola, t. 119, &c. (70) [Common Reed, and Sea Club Rush ; both natives.] [71] Marsh Rosemary. S *3$ MARGINS OF LEAVES. This term is opposed to all kinds of teeth, notches, or incisions. It regards solely the margin of a leaf; whereas integrum, p. 131, respects its whole shape, and has nothing to do with the margin. English writers who translate the one entire, and the other very entire, are therefore incorrect. ISpinosum,f. 77, spinous, beset with prickles, as Car- duus lanceolatus, t. 107, and Eryngium campestre, t. 57. The veins are spinous in Solanum Pyracantha, Exot. Bot. t. 64, &c, Xnerme.f. 71, unarmed, is opposed to spinous. Ciliatum, f 78, fringed, bordered with soft parallel hairs, as Galium cruciatum, Engl. Bot. t. 143. Cartilagineum, cartilaginous, hard and horny, as Saxi- fraga callosa, Dicks. Dr. PL n. 63. Dentatum,f. 79, toothed, beset with projecting, hori- zontal, rather distant teeth of its own substance, as A triplex laciniata, Engl. Bot. t. 165, Hypocharh maculata, t. 225, and the lower leaves of. Centaurea Cyanus, t. 277 / also Nymphcea Lotus, Curt. Mag. t, 797,(71) f$erratum,f. 80, serrated, when the teeth are sharp, and resemble those of a saw, pointing towards the extrem- ity of the leaf. Examples of this are frequent, as Urtica, (72) t.1'8 and 1236, Rosa, t. 992, &c, Coma- rum palustre,(7 3) t.172, and Seneciopaludosus, t.650; also Dillenia indica, Exot. Bot. t. 2. Some leaves are doubly serrated, duplicato-serrata, having a se- ries of smaller serratures intermixed with the larger, (71) [And Arrow wood, Viburnum dentatum."] (72) [Nettle.] (73) [Marsh Cinquefpil, native.] MARGINS OF LEAVES'. 139 as Mespilusgrandiflora, t. \8, and Campanula Trd* chelium, Engl. Bot. t. 12; ■Serrulatum, f. '63, minutely serrated, is used when thd teeth are very fine, as in Polygonum amphibium, £.- 436, and Empleurum serrulatum, Exot. Bot. t. 63. Crenatum, f. 81, notched, or crenate, when the teeth are rounded, and not directed towards either end of the leaf, as in Ground-Ivy, Glechonia hederacea, t. 853, Chrysosplenium, t. 54 and .90, and Sibthorpia europoza, t. 649. In Saxifraga Geiim, i. 1561, the leaves are sharply crenate. In the two British spe- cies of Salvia, t. 153 and 154, the radical leaves are doubly crenate, f 82. Erosum, f 83, jagged, irregularly cut or notched, es- pecially when otherwise divided besides, as in Sene- cio squalidus, t. 600. Repandum, f. 84, wavy, bordered with numerous mi- nute angles, and small segments of circles alternatelv as Menyanthes nympheeoidesj t. 217, and Inula dijsen- terica, t. 1115.. Glandulosum, glandular, as Hypericum' montanum, t. 371 and the Bay-leaved Willow, Salix pentandra. Revolutum, revolute, when the margin is turned or rol- led backwards, as Andromeda polifolia, t. 713, and Tetratheca glandulosa, Exot. Bot. t. 2l.- Linnaeus seems originally to have applied this term to the rolling of the whole leaf backwards, as in Soli- dago Virgaurea, Engl. Bot. t. 301, meaning to usq the expression margine revolutum when the margin? was intended ; but this latter case being extremely frequent and the other very rare, he fell into the prae- lice of using revolutum simply for the margin. 140 SURFACE OF LEAVES. Involutum, involute, the reverse of the preceding, as in Pinguicula, t. 70 and 145. Conduplicatum, folded, when the margins are brought together in a parallel direction, as in Roscoeapurpurea, Exot. Bot. t. 108. 7. Terms expressive of different kinds of surface, apply- ing equally to the leaf and to the stem, have been al- ready explained, p. 111. To these may be added the following, chiefly appropriated to leaves. Punctatum, dotted ; either superficially as in Rhododen- drum punctatum, Andr. Repos. t. 36, and Melaleuca linarifolia, Exot. Bot. t. 56 ; or through the sub- stance, as in Hypericum perforatum, (74) Engl. Bot. t. 295, and the whole natural order to which the Or- ange and Lemon belong. Rugosum, rugged, when the veins are tighter than the surface between them, causing the latter to swell in- to little inequalities, as in various species of Sage, Salvia. See Flora Greeca ; also Teucrium Scorodo' nia, Engl. Bot. t. 1543. Bullatum, blistery, is only a greater degree of the last, as in the Garden Cabbage, Brassica oleracea. Plicatum,f. 85, plaited, when the disk of the leaf, es- pecially towards the margin, is acutely folded up and down, as in Mallows, and Alchemilla vulgaris, Engl. Bot. t. 597, where, however, the character is but ob- scurely expressed. Undulatum,f. 86, undulated, when the disk near the margin is waved obtusely up and down, as Reseda (74) [Common St. John's wort.} VEINS AND RIBS OF LEAVES. 141 kitea, t. 321, and Ixia crispa (more properly undu- lata*) Curt. Mag. t. 599. Crispum, f. 87, curled, when the border of the leaf be- comes more expanded than the disk, so as to grow elegantly curled and twisted, which Linnaeus consid- ers as a disease. Malva crispa, Ger. em. 931, is an example of it, and may probably be a variety of M. verticillata, Jacq. Hort. Vind. v. 1. t. 40. Concavum, hollow, depressed in the middle, owirg to a tightness in the border, as Cyamus Nelumbo, Exot. Bot. t. 32. Venosum, f. 88, veiny, when the vessels by which the leaf is nourished are branched, subdivided, and more or less prominent, forming a network over either or both its surfaces, as Crataegus, or rather Pyrus, tor- minalis, Engl. Bot. t. 298, and Verbascum Lychmtis, t 58. Nervosum, f. 89, or costatum, ribbed, when they extend in simple lines from the base to the point, as in Cyp- ripedium Calceolus, t. 1, the Convallaria, t. 279 and 280, Stratiotes alismoides, Exot. Bot. t. 15, and Roxburghia viridflora, t. 57. The greater clusters of vessels are generally called nervi or costa?, nerves or ribs, and the smaller vena, veins, whether they are branched and reticulated, or simple and parallel. Avenium, veinless, and enerve, ribless, are opposed to the former. Trinerve, f. 90, three-ribbed, is applied to a leaf that has three ribs all distinct from the very base, as well as unconnected with the margin, in the manner of * Saliai. Hort. .37. I4i VEINS AND RIBS OF LEAVES. those many-ribbed leaves just cited, as Blakea tririef- vis*, Curt. Mag. t. 451. Basi trinerve, f. 91, three-ribbed at the base, is whew the base is cut away close to the lateral ribs, as in Burdock, Arctium Lappa. Engl. Bot. t. 1228, Tussi- lago, t. 430 and 431, and the Great Annual Sunflow- er. Triplinerve, f. 92, triply-ribbed, when a pair of large ribs branch off from the main one above the base, which is the case in many species of Sunflower or Helianthus, Laurus Cinnamomum ahd Camphora, as well as Blakea triplinervis, Aublet Guian. t. 210. Coloratum, coloured, expresses any colour in a leaf be- sides green, as in Arum bicolor, Curt. Mag. t. 820, Amaranthus tricolor, and others of that genus, Jus- ticia picta, Hedysarum pictum, Jacq. Ic. Rar. t. 5C>7, Tradescantia discolor, Sm. Ic. Pict. t. 10, Pulmonu- ria officinalis, Engl. Bot. t. 118. Variegatum, variegated, is applied to a sort of variety or disease, by which leaves become irregularly blotched with white or yellow, like those of Striped Grass, Arundo colorata, Fl. Brit. ;. as also the Elder, the Mentha rotundifolia, Engl. Bot. t. 446, and the Ju- euba japonica, which last is not known in our gardens in its natural green state. Nudum, naked, implies that a leaf is destitute of all kinds' of clothing or hairiness, as in the genus Orchis. Nu- dus applied to a stem means that it bears no leaves, and to a flower that it has no calyx. * Authors incessantly use the termination trinervius, triner- via, &c. for the more classical trinervis, trinerve, enervis, enerve. SUBSTANCE, &c. OF LEAVES. 143 8. The following terms express the substance, peculiar configuration, or any other remaining circumstances of leaves, not already explained. Teres, f. 93, cylindrical, as those of Conchium gibbosum, White's "Voyage, t. 22. f. 2 ; see Cavanilles Icones, t. 533, and 534. Semicylindraceum, f 94, semicylindrical, flat on one side, as Salsola fruticosa, Engl. Bot. t. 635, and Chenopodium maritimum, t. 633. Subulatum, f 95, awlshaped, tapering from a thickish br.sr to a point, as Salsola Kali, t 634. (75) Tubulosum, tubular, hollow within, as Allium Cepa, the Co.umon Onion. The leaf of Lobelia Dortmanna, Engl. Bot. t. 140, is very peculiar in consisting of a double tube,/ 96. Carnosum,f.98, fleshy, of a thick pulpy substance, as in all those called succulent plants, Crassula lactea, Exo. Bot. t. 33, Aloe, Sedwn, Mesembryanthemum, &c. See, Sempervivum tectorum, Engl. Bot. t. 1320. Gibbum, gibbous, swelling on one side or both,, from excessive abundance of pulp, as Aloe retusa, Curt. Mag. t. 155. Compressum, f 98, compressed, flattened laterally, as Mesembryanthemum uncinatum, Dill. Elth. t. 198, and acinaciforme, t, 211, Depressum, depressed, flattened vertically, as M. lingui* forme, t. 183^-185. Seep. 1^7. Canaliculatum, f. 97, channelled, having a longitudinal furrow, as M. pugioniforme, t. 210, Phntago marir (75) [Saltwort] 144 SUBSTANCE, &e. OF LEAVE*. tima, (76) Engl. Bot. t. 175, and Narcissus poeticus, t. 275. Carinatum, keeled, when the back is longitudinally prominent, as Narcissus biflorus, t. 276. Ensiforme, sword-shaped, is a two-edged leaf, tapering to a point, slighdy convex on both surfaces, neither of which can properly be called upper or under, as in most of the genus Iris. (77) See Curt. Mag. t. 671, t. 9, &c, and Fl. Grcec. t. 39 and 40. Anceps, two-edged, is much the same as the last. Acinaciforme, scimitar-shaped, compressed, with one thick and straight edge, the other thin and curved, as Mesembryanthemum acinaciforme above mentioned. Dolabriforme, f 98, hatchet-shaped, compressed, with a very prominent dilated keel, and a cylindrical base, as M. dolabriforme, Dill. Elth. t. 191, Curt. Mag, t. 32. These two last terms might well be spared, as they seem contrived only for the plants in question, and in- deed are not essentially distinct from each other. Trigonum,f. 99, three-edged, having three longitudinal sides and as many angles, like M. deltoides, Dill. Elth. t. 195, Linn. Phil. Bot. t. \.f. 58. Linnaeus has erroneously referred to this figure to illustrate his term de'toides ; misled, as it should seem, by the name of the plant to which it belongs ; but his defi- nition is foreign to the purpose, see p. 133, and alludes to the outline of a flat leaf. Trjquetrum differs from trigonum only in being used by Linnaeus for a three-sided awl-shaped leaf, as M. (76) [Sea Plantain, native.] (77) [Flag, or Flower de luce.l SUBSTANCE, &c. OF LEAVES. 145 emarginatum, Dill. Elth. t. 197, f. 250, and bicolor* um, t. 202, also Saxifraga burseriana. Tetragonum, f 100, four-edged, having four prominent angles, as Iris tuberosa, Fl. Grcec. t. 41. Lingulatum, tongue-shaped, of a thick, oblong, blunt figure, generally cartilaginous at the edges, as Mesem- bryanthemum linguiforme, Dendrobium linguifbrme, Exot. Bot. t.ll, and several species of Saxifraga, as S. mutata, Curt. Mag. t. 351, S. Cotyledon, &c. Membranaceum, membranous, of a thin and pliable tex- ture, as in Aristolochia Sipho, t. 534, Rubus odoratus, (78) t. 323, Magnolia purpurea, t. 390, &c. Coriaceum, leathery, thick, tough and somewhat rigid, as Magnoliagrandiflofa,(79) and Hydrangea hortensis, Sm. Ic. Pict. t. 12, Curt. Mag* t. 438. Sempervirens, evergreen, permanent through one, two, or more winters, so that the branches are never strip- ped, as the Ivy, the Fir, the Cherry Laurel, the Bay,&c. Deciduum, deciduous, falling off at the approach of win- ter, as in most European trees and shrubs. Alienatum,f. 101, alienated, when the first leaves of a plant give place to others totally different from them and from the natural habit of the genus, as in many Mimosa of New Holland ; see M. verticillata, Curt. Mag. t. 110, and myrtifolia, t. 302 / also Lathyrus Nissolia, Engl. Bot. t. 112. The germination of this last plant requires investigation, for if its first leaves be pinnated, it is exactly a parallel case with the New Holland Mimosa. (78) [Flowering Raspberry, native, as also the preceding.] (7y) [Big Laurel of the South«rn states.] T I*6 SUBSTANCE, &c. OF LEAVES. Cucullatum,f. 102, hooded, when the edges meet in the lower part, and expand in the upper, as those of the curious genus Sarracenia. Curt. Mag. t. 780 and 849, and S. adunca, Exot. Bot. t. 53.(78) Appendiculatum, f. 103, furnished with an additional organ for some particular purpose not essential to a leaf, as Dionaa muscipula, Curt. Mag. t. 785, cul- tivated very successfully by Mr. Salisbury, at Bromp- ton, whose leaves each terminate in a pair of toothed irritable lobes, that close over and imprison insects; or Nepenthes distillatoria, Rumph. Amboin. v. 5. t. 59, f. 2, the leaf of which bears a covered pitcher, full of water. Aldrovanda vesiculosa, and our Utricu- lar'uz, Engl. Bot. t. 253, 254, have numerous blad- ders attached to the leaves, which seem to secrete air, and float the plants. Many of the preceding terms applied to leaves are occasionally combined to express a form between the two, as ovato-lanceolatum, lanceolate inclining to ovate, or elliptico-lanceolatum, as in the Privet, Engl. Bot. t. 764. When shape, or any other character, cannot be « precisely defined, sub is prefixed to the term used, as subrotundum, roundish, subsessile, not quite destitute of a footstalk, to which is equivalent subpetiolatum, ob- scurely stalked. By the judicious use of such means, all necessary precision is attained. It is to be wished that authors were always uniform and consistent, at least (78) [A leaf is said to be hooded, whether.the edges unite so as to form a perfect cavity, as in Sarracenia, or Fivesaddle flow- er ; or whether they simply meet without cohering, as in Viola cucullataJ] COMPOUND LEAVES. 147 with themselves, in the application of terms ; but as Linnaeus, the father of accurate botanical phraseology, very frequently misapplies his own terms, it is perhaps scarcely to be avoided. I have observed botanists most critical in theory, to be altogether deficient in that char- acteristic phraseology, that power of defining, which bears the stamp of true genius, and which renders the works of Linnaeus so luminous in despite of incidental errors. Perhaps no mind, though ever so intent on the subject, can retain all the possible terms of description and their various combinations, for ready use at any giv- en moment. There are few natural objects to which a varie- ty of terms are not equally applicable in description, so that no two writers would exactly agree in their use. Neither is Nature herself so constant as not perpetually to elude our most accurate research. Happy is that natur- alist who can seize at a glance what is most characteris- tic and permanent, and define all that is essential, with- out trusting to fallacious, though ever so specious, dis tinctions ! 9. Folia composita, compound leaves, consist of two or any greater number offoliola, leaflets, connected by a common footstalk. Folium articulatum, f. 104, a jointed leaf, is when one leaflet, or pair of leaflets, grows out of the summit of another, with a sort of joint, as in Fagara tragodes, Jacq. Amer. t. 14, Digitatum, f 22, digitate or fingered, when several leaflets proceed from the summit of a common foot. AiS COMPOUND LLAM." stalk, as Potentilla verna, Engl. Bot. t. 37, reptans, (79) t. 862, and Alchemilla alpina, t. 244., Binatum,f 105, binate, is a fingered leaf consisting of only two leaflets, as in Zygophyllum, Curt. Mag. t. 372. Ternatum,f. 106, ternate, consists of three leaflets, as Fagonia cretica, t. 241, and the genus Trifolium Trefoil. See Engl. Bot. t. 190, &c. Quinatum, quinate, of five leaflets, as Potentilla alba, t. 1J.'j4, reptans, t. 862, &c. Pinnatum, pinnate, when several leaflets proceed laterally from one footstalk, and imitate a pinnatifid leaf, p. 135. This is of several kinds. cum impuri,f. 116, with an odd, or terminal, leaflet, as in Roses, and Elder, also Polemonium cozruleum, Engl. Bot. t. 14, and Hedysarum Onobrychis, t. 96. cirrosum, f. 115, with a tendril, when furnished with a tendril in place of the odd leaflet, as the Pea and Vetch tribe ; Pisum maritimum, t. 1046, Lathyrus palustris, (80) t. 169, Vicia sativa, t. 334. abrupte,f. 101, abruptly, without either a terminal leaf le or a tendril, as Cassia Chamaecrista, (80) Curt. Mag. t. 107, and the genus Mimosa. See M. pudica, the Common Sensitive-plant. This form of leaf is much more uncommon than the imparipinnatum, and we have no perfect example of it among British plants. The nearest approach to it is the genus Orobus, whose leaves have only the rudiments of a tendril. A truly wonderful variety of the Oroius sylvaticus, (79) \Cinquefoil, or FivefingCl'."] (80) [Both native.] COMPOUND LEAVES. 140 Engl. Bot. t. 518, with large simple leaves, has been •found in Wales. opposite, oppositely, when the leaflets are opposite, or in pairs, as Saint-foin, t. 96, Roses, Sium angustifolium, t. 139, &c. alternatim, alternately, when they are alternate, as Vicitt, dumetorum (Cracca sylvatica) Riv. Pent. Irr. t. 51, and occasionally in our V. Sativa lutea, &c. j,nterrupte,f. 107, interruptedly, when the principal leaf- lets are ranged alternately with an intermediate series of smaller ones, as Spiraea Filipendula, Engl. Bot. t. 284, S. Ulmaria, t. 960, and Potentilla anserina, t. 861. (81) articulate, jointedly, with apparent joints in the common footstalk, as Weinmannia pinnata. decursive, decurrently, when the leaflets are decurrent, as Eryngium compestre, Engl. Bot. t. 57, and Poten- tilla fruticosa, t. 88, lyrato,f. 108, in a lyrate manner, having the terminal leaflet largest, and the rest gradually smaller, as they approach the base, as Erysimum pracox, t. 1129, and, with intermediate smaller leaflets, Geum rivale, (82) t. 106 ; also the Common Turnip. Such leaves are usually denominated lyrate in common with those properly so called (whose shape is simple, and not formed of separate leaflets); nor is this from inac- curacy in botanical writers. The reason is, that these two kinds of leaves, however distinct in theory, are of all leaves most liable to run into each other, even on the same plant, examples of which are fre- quent in the class Tetradynamia. f8l) rxativc.i (82) [Native.] 150 COMPOUND LEAVES. verticillato,f. 109, in a whorled manner, the leaflets cut into fine divaricated segments, embracing the foot- stalk, as Sium verticillatum, Fl.Brit. Eng.Bot. t.395. Auriculatum,f. 110, an auricled leaf, is furnished at its base with a pair of leaflets, properly distinct, but oc- casionally liable to be joined with it, as Salvia triloba, Fl. Grcec. t. 17, and Dipsacus pilosus, Engl. Bot. t. 877. Linnaeus in the last example uses the term appendiculatum, which is correct, but superfluous, and I have therefore ventured to apply it somewhat differ- ently,/?. 146. Conjugatum, f. 105, conjugate, or yoked, consists of only a pair oi pinna or leaflets, and is much the same as binatum. Instances of it are in the genus Zygb- phyllum, whose name, equivalent to Yokeleaf, ex- pressed this very character ; also in Lathyrus sylves- tris, Engl. Bot. t. 805, and latifolius, t. 1108. Biju- gum, trijugum, quadrijugum, multrijugum, &c, ex- press particular numbers of pairs of leaflets, and arc used for that purpose where such discrimination is requisite for specific characters, as in Mimosa. The different degrees in which leaves are compounded are thus distinguished, without any reference to the mode. Compositum,f. Ill, simply compound, as in the above instances. Decompositum, f. 112*, doubly compound, as Atha- manta, Libanotis, Engl. Bot. t. 138, AEgopodium, Po- * Linnaeus, in Phil. Bot. 47, gives an erroneous definition of this term, which does not accord with his own use of it. Pro- fessor Martyn has rightly defined it. G0MP0UND LEAVES. 151 dagraria, t. 940, and Fumaria claviculata, t. 103. Supradecompositum,f. 113, thrice compound, or more, as Caucalis Anthriscus, t. 987, C. daucoides t. 197, and Bunium flexuosum, t. 988. But Bigeminatum, twice paired, as Mimosa Unguis cati, Plum. Ic. t. 4 ; and tergeminatum, thrice paired, as M. tergemina ; also Biternatum,f 112, twice ternate, as JEgopodium, Engl. Bot. t. 940 ,* triternatum, thrice ternate, as Fumaria lutea, t. 588 ; and Bipinnatum, doubly pinnate, tripinnatum, triply pinnate, of which examples have just been given : all apply to the mode, as well as the degree, in which leaves are compounded. Pedatum,f. 114, pedate, is a peculiar kind of leaf, be- ing ternate, with its lateral leaflets compounded in their fore part, as Helleborus fatidus, Engl. Bot. t. 613, and H. niger, Curt. Mag. t. 8. (83) There is an affinity between a pedate leaf and those simple ones which are three-ribbed at the base, p. 142. See also the disposition of the lateral veins in Aristolochia Clematitis, Engl. Bot. t. 398. In compounding the foregoing terms we must take care not to express a contradiction. Thus the leaves of many Mimosa, as the purpurea, Andr. Repos. t. 372, and sensitwa, are conjugata pinnata, conjugate in the first instance, pinnate in the next, not conjugato-pinnata, of an intermediate nature between conjugate and pin- (83) [Also Viola ftedata.~\ 152 COMPOUND LEAVES nate, which is impossible. Neither are the leaves of Mimosa pudica digitato-pinnata, for there is no medium between the two terms ; but they are digitate, or com- posed of leaflets proceeding from the top of a common foot-stalk, and those leaflets are pinnate. On the other hand ovato-lanceolatum, lanceolate approaching to ovate, or elliptico-lanceolatum, approaching to elliptic, as in the Privet, Engl. Bot. t. 764, already mentioned, whose leaves often assume that shape, are easily understood. C 153 ] CHAPTER XVI. OF THE FUNCTIONS OF LEAVES. The knowledge of the functions of leaves, and their real use with regard to the plant, is a curious branch of vegetable physiology, which made but a slow progress long after the nature of many other parts had been deep- ly scrutinized and thoroughly explained. Caesalpinus (De Plantis, p. 6.) thought leaves merely a clothing, or a protection against cold and heat. He conceived that the rays of the sun, being moderated in passing through them, were prevented from acting too violently on the fruit and young buds. " Accordingly," says he, " many trees lose their leaves in autumn, when their fruits are perfected, and their buds hardened, while such as retain the fruit long, keep also their leaves ; even till a new crop is produced, and longer, as in the Fir, the Arbutus, and the Bay. It is reported that in hot climates, where there is almost perpetually a burning sun, scarcely any trees lose their leaves, because they require them for shade." Caesalpinus goes on to show that leaves proceed from the bark, with some remarks on the pith, (in which we may trace the origin of the Linnean hypothesis of vegetation,) but which are now superseded by more accurate inquiries. The above is certainly a very small part of the use of leaves. Yet the observations of this writer, the father of botanical philosophy among the moderns, are so far c©r- U 154 PERSPIRATION OF LEAVES. rect, that if the leaves of a tree be stripped off, the fruit comes to nothing, which is exemplified every year in Gooseberry bushes devoured by caterpillars ; and though the fruit-trees of warm climates, partly natural- ized with us, Grapes and Peaches for instance, ripen their fruit sooner perhaps if partially deprived of their leaves, yet if that practice be carried too far, the fruit perishes, as gardeners who tried it soon discovered. The White Mulberry indeed, cultivated in the south of Eu- rope for the food of silkworms only, bears wonderfully the loss of its foliage three or four times a year. How far the fruit is injured nobody thinks it worth while to inquire, as it is never eaten, but it certainly does not fall off prematurely. That Leaves imbibe and give out moisture has been long known, this being one of the most obvious facts belonging to them. Dr. Hales thought they might probably imbibe air ; but since his time more certain discoveries have been made concerning this point, as well as the effect of light upon leaves, which also did not escape the consideration of that great philosopher. All these subjects we shall mention- in their turn. That Leaves give out moisture, or are organs of in- sensible perspiration, is proved by the simple experi- ment of gathering the leafy branch of a tree, and imme- diately stopping the wound at its base with mastick, wax, or any other fit substance, to prevent the effusion of moisture in that direction. In a very short time the leaves droop, wither and are dried up. If the same branch, partly faded, though not dead, be placed in a very damp cellar, or immersed in water, the leaves re PERSPIRATION OF LEAVES. 155 vive, by which their power of absorption is also proved. Hence the use of a tin box to travelling botanists, for the purpose of restraining the evaporation of plants, and so preserving them fresh for some days till they can be examined, as well as of reviving faded plants, if the in- side of the box be moistened before they are shut up in it. Dr. Hales found that a plant of the Great Annual Sun- flower, Helianthus annuus, lost 1 lb. 14 oz. weight in the course of twelve hours in a hot dry day. In a dry night it lost about 3 oz.; in a moist night scarcely any alteration was observable, but in a rainy night it gained 2 or 3 oz. The surface of the plant compared with that of its roots was, as nearly as could be calculated, in the proportion of five to two ; therefore the roots must have imbibed moisture from the earth of the pot in which the plant grew, and which was all previously weighed, in the same proportion of five to two, otherwise the leaves would have faded. The same experiment was made on the Vine, the Cabbage, &c, with various re- sults as to the exact degree of perspiration, but all prov- ing it to be considerable. Evergreens are found to perspire much less than other shrubs. The state of the atmosphere has a great effect on the rapidity of this perspiration. Practical botanists know how much sooner plants fade, and haymakers experi- ence how much faster their work is done, some days than others, and those days are by no means always the most sunny. In a hot dry day plants are often exhaust- ed, so as to droop very much towards evening, especial- ly in the dry unsheltered bed of a garden. Such as have isi SENSIBLE PERSPIRATION. fleshy roots, indeed have a singular power of resisting drought, which has already been explained p. 101. Suc- culent plants, destined to inhabit sunny rocks, or sandy deserts, imbibe with the greatest facility, and perspire very sparingly. Evergreens are not generally very suc- culent, but their cuticle appears to be constructed like that of succulent plants, so as to allow of little evapora- tion. The Cornelian Cherry, whose immense perspi- ration we have recorded, p. 67, has a thin dry leaf, ca- pable of holding very little moisture. The nature of the liquor perspired has been already noticed, p. 67. In hot weather it has been observed by Hales, Du Hamel and Guettard to partake occasionally of the peculiar scent of the plant that yields it, but in general the odorous matter is of too oily a nature to be combined with it. The sensible perspiration of plants is of various kinds. When watery, it can be considered only as a condensa- tion of their insensible evaporation, perhaps from some sudden change in the atmosphere. Groves of Poplar or Willow exhibit this phcenomenon, even in England, in hot calm weather, when drops of clear water trickle from their leaves like a slight shower of rain. Some- times it is of a saccharine nature, as De la Hire observ- ed in Orange trees ; Du Hamel Arb. v. 1. 150. It is more glutinous in the Tilia or Lime-tree, more resin- ous in Poplars, as well as in Cistus creticus, from which last the resin called Labdanum is collected, by beating the shrub with leather thongs. See Tournefort's Voyage, 29. In the Fraxinella, Dictamus albus, it is a highly mflammable vapour. Ovid has made an elegant use of ABSORPTION OF LEAVES. 15f the resinous exudation of Lombardy Poplars, Populus dilatata, Ait. Hort. Kew. v. 3. 406, which he supposes to be the tears of Phaeton's sisters, who were transform- ed into those trees. Such exudations must be consid- ered as effusions of the peculiar secretions; for it has been observed that Manna may be scraped from the leaves of Fraxinus Ornus, Fl. Grac. t. 4, as well as procured by incision from its stem. They are often perhaps a sign of unhealthiness in the plant; at least such appears to be the nature of one kind of honey-dew, to which the Beech in particular is subject, and which, in consequence of an unfavourable wind, covers its leaves in the form of a sweet exudation, similar in fla- vour to the liquor obtained from its trunk. So likewise the Hop, according to Linnaeus, Faun. Suec. 305, is af- fected with the honey-dew, and its flowers rendered abortive, in consequence of the attacks of the caterpillar of the Ghost Moth, Phalana Humuli, upon its roots. In such case the saccharine exudation must decidedly be of a morbid nature*. That wax is also an exudation from the leaves of plants, appears from the experiments recorded by Dr. Thomson in his Chemistry, v. 4. 298, and it has been long ago asserted that wax may easily be gathered from the leaves of Rosemary. On this sub- ject I have not made any experiments to satisfy myself. With respect to the absorbing power of leaves, the best observations that have been made are those of Bon- * I do not mean to dispute the accuracy of Mr. Curtis's excel- lent paper, Tr. of Linn. Soc. v. 6, written to prove honey-dew to be the dung of Afthides. I only contend that there are more than one kind of honey-dew. 15S ABSORPTION OF LEAVES net, recorded in the beginning of his Recherches sur I'Usagedes Feuilles. His aim was, by laying leaves of various plants upon the top of a jar of water, some with their upper, and others of the same species with their under, surfaces applied to the water, to discover in which situation leaves of each plant continued longest in health and vigour, and also how far different species differed from each other in this respect. The results were in many instances highly curious. Of fourteen herbaceous plants tried by this philoso- pher, six lived nearly as long with one surface applied to the water as with the other ; these were the common Arum maculatum, the French Bean, the Sun-flower, Cabbage, Spinach and the Small Mallow. By the last I presume is meant Malva rotundifolia, Engl. Bot. t. 1092. Six others, Plantain, White Mullein, the Great Mallow (probably M. sylvestris, t. 671), the Nettle, Cock's-comb, and* Purple leaved Amaranth (probably Amaranthus hypochondriacus), lived longest with their upper surface laid upon the water. The Nettle lived but three weeks with its under surface on the water, and about two months in a contrary position. The Mullein scarcely survived five or six days, and the Amaranth not a week, in the first-mentioned posture, while the leaves of the former remained in vigour about five weeks, and of the latter three months, when their upper surfaces imbibed the water. Marvel of Peru and Balm, the two remaining plants of the fourteen on which the experiment was made, had also an evident advantage in receiving that fluid by their upper surfaces. The leaves of some of the above species were found to thrive bet- ABSORPTION OF LEAVES. 159 ter when their stalks only were immersed in water, than when either of their sides was supplied with it, and the reverse was observable in several others ; but the White Mullein, the Plantain and the Amaranth survived lon- ger when they received the water by their stalk than by their under surface, though not so long as when it was applied to their upper sides. Of sixteen trees tried by Bonnet, the Lilac and the Aspen, Populus tremula, were the only leaves that seemed to imbibe water equally well by either surface, whilst all the others evidently succeeded best with their under sides laid upon the water being in that respect the reverse of herbaceous plants. Of these the White Mulberry leaf was the most remarkable, not living more than five days when supplied by the upper surface, while such as floated on their backs continued in per- fection near six months. The Vine, the Poplar (prob- ably Populus nigra), and the Walnut, were no less re- markable, for fading almost as soon, when fed by their upper surface, as when left without any water at all. Many of the other trees imbibed water as well, or bet- ter, by their foot-stalks as by their upper surfaces. Ha- zel-nut and Rose leaves, when laid with their backs up- on the water, imbibe sufficiently to nourish other leaves on the same branch ; so will one leaflet of a French bean supply its neighbour that does not touch the water. Those who wish to repeat these experiments should be careful to choose full-grown healthy leaves, all as nearly as possible of the same age and vigour. It is also desirable that the precise species of plant should be recorded by its scientific name. Fo/ want of this,Bonnet, who despised method and nomenclature, has left us in 160 ©F AQUATIC PLANTS. uncertainty concerning several of the plants he examin- ed. We ought to have been accurately informed what species of Poplar differed so remarkably in its power of absorption from the Aspen, another of the same genus. We ought likewise to have been told what Sun-flower, what Nettle, Amaranth and Mallows were examined ; for want of which information the authority of such ex- periments is much impaired. From the foregoing observations we learn the impor- tance of shading and watering plants newly removed, cuttings, grafts, &c. and on the other hand the benefit of heat and air to promote due perspiration and evapora- tion. The perspiration of aquatic plants seems to be re- markably copious. Of these some grow constantly im- mersed in the water, as most species oi Potamogeton, Pond-weed, Engl. Bot. t. 168, 297, 376, &c. Their leaves are peculiarly vascular, and dry very quickly in the air, withering in a very few minutes after exposure to it. Their absorbing power seems equally great, so that they appear to be continually, in their natural situa- tion, imbibing and giving out a quantity of water much greater than has been observed in land plants. Other aquatics, as the Nymphaa, Engl. Bot. t. 159, 160, float with only the upper surface of their leaves exposed to the air, which surface is so contrived that water will scarcely remain upon it. These leaves, though extreme- ly juicy, dry with great rapidity, as does every part of the plants when gathered. It is probable that they im- bibe copiously by their under sides, and perspire by the upper. SARRACENIA. 161 The cecondmy of the Sarracenia, an American ge- nus of which we now know four species, and of the East Indian Nepenthes distillatoria, deserve particular men- tion. Both grow in bogs, though not absolutely in the water. The former genus has tubular leaves which catch the rain like a funnel and retain it; at least such is the nature of S. purpurea, Curt. Mag. t. 849, whose margin seems dilated expressly for this purpose, while the orifice of the tubular part just below is contracted to restrain evaporation. Linnaeus conceived this plant to be allied in constitution to Nymphcea, and consequently to require a more than ordinary supply of water, which its leaves were calculated to catch and to retain, so as to enable it to live without being immersed in a river or pond. But the consideration of some other species ren- ders this hypothesis very doubtful. S.flava, t.780, and more especially S. adunca, Exot. Bot. t. 53, are so con- structed that rain is nearly excluded from the hollow of their leaves, and yet that part contains water, which seems to be secreted by the base of each leaf. What then is the purpose of the unusual contrivance ? An observation communicated to me two years ago, in the botanic garden at Liverpool, seems to unravel the mys- tery. An insect of the Sphex or Ichneumon kind, as far as I could learn from description, was seen by one of the gardeners to drag several large flies to the Sarracenia adunca, and, with some difficulty forcing them under the lid or cover of its leaf, to deposit them in the tubular part, which was half filled with water. All the leaves, on being examined, were found crammed with dead or drowning flies. The S. purpurea is usually observed w Iu2 NEPENTHES. to be stored with putrefying insects, whose scent is perceptible as we pass the plant in a garden ; for the margin of its leaves is beset with inverted hairs, which, like the wires of a mousetrap, render it very difficult for any unfortunate fly, that has fallen into the watery tube, to crawl out again. Probably the air evolved by these dead flies may be beneficial to vegetation, and, as far as the plant is concerned, its curious construction may be designed to entrap them, while the water is provided to tempt as well as to retain them. The Sphex or Ichneu- mon, an insect of prey, stores them up unquestionably for the food of itself or its progeny, probably depositing its eggs in their carcases, as others of the same tribe lay their eggs in various caterpillars, which they sometimes bury afterwards in the ground. Thus a double purpose is answered; nor is it the least curious circumstance of the whole, that an European insect should find out an Amer- ican plant in a hot-house, in order to fulfil that purpose. If the above explanation of the Sarracenia be admit- ted, that of the Nepenthes will not be difficult. Each leaf of this plant terminates in a sort of close-shut tube, like a tankard, holding an ounce or two of water, cer- tainly secreted through the footstalk of the leaf, whose spiral-coated vessels are uncommonly large and nume- rous. The lid of this tube either opens spontaneously, or is easily lifted up by insects and small worms, who are supposed to resort to these leaves in search of a purer beverage than the surrounding swamps afford. Rum- phius, who has described and figured the plant, says " various little worms arid insects crawl into the orifice, and die in the tube, except a certain small squilla or AIR-VESSELS OF THE LEAVES. 16. shrimp, with a protuberant back, sometimes met with, which lives there."—I have no doubt that this shrimp feeds on the other insects and worms, and that the same purposes are answered in this instance as in the Sarrace- nia. Probably the leaves of Dioncea muscipula, as well as of the Drosera, Engl. Bot. t. 867—869, catch in- sects for a similar reason. I proceed to consider the effects of Air and Light up- on vegetables. Dr. Grew, by the assistance of the microscope, de- tected a quantity of vesicles full of air in the leaves of plants, as also the spiral-coated vessels of their stems, which last he and all other physiologists, till very lately, considered as air-vessels likewise, Malpighi made the same observations about the same time ; and as these two acute and laborious philosophers pursued their in- quiries without any mutual communication, their discov- eries strengthen and confirm each other. Their books have long served as magazines of facts for less original* writers to work with. From their remarks physiolo- gists have theoretically supposed that leaves imbibed air, which the spiral vessels were believed to convey all through the plant, in order that it might act on the sap as it does on the animal blood, The analogy thus un- derstood was not correct, because air is conveyed no further than the lungs of animals; but without this hy- pothesis no use could be found for the supposed longi- tudinal air-vessels. The observations of Dr. Hales come next in order to those of Grew and Malpighi. By means of the air-pump, tn instrument much in use in his time, Hales obtained 164 AIR-VESSELS OF THE LEAVES. abundance of air from every part of the vegetable body, as well as from recently extracted sap. Plants were found to perish very soon in an exhausted receiv- er. Some of this great man's experiments, however, require to be received with caution. He rightly re- marked that air was not only taken in by plants very copiously along with their food, but also imbibed bf their bark ; see Veg. Staticks, chap. 5. But when, from observing that it would freely from the bark per- vade the longitudinal vessels of a branch, he concluded that Malpighi and Grew were right in their ideas of longitudinal air-vessels, he was misled by appearances. We cannot but be aware that, when a branch is gather- ed, the sap must soon flow out of those spiral-coated tubes, which are large, elastic, and, no doubt, irritable. After they are emptied, air may unquestionably pass through them, especially when the whole weight of the fc atmosphere is acting, as in Dr. Hales' experiments with the air-pump, upon so delicate a fabric as the internal vascular structure of a plant, forcing its way through pores or membranes not naturally designed to admit it. We must also recollect that a plant, cut even for a short time, begins to lose its vital principle, after which no just judgment can be formed, by any experiments, con- cerning the movements of its fluids in life and vigour, S e Chapter 1, These experiments of Dr. Hales there- fore prove no more than that the vegetable body is per- vious in various directions ; and perhaps the only point they correctly establish is, that air is imbibed through the bark, a part known to be full of air-vessels. But the seventh chapter of the Vegetable staticks contains EFFECTS OF AIR ON LEAVES; 165 some remarks much more to our purpose. Dr. Hales there clearly anticipates by conjecture, what succeeding philosophers, more enlightened chemists, have ascer- tained. His words are remarkable : " We may therefore reasonably conclude, that one great use of leaves is what has been long suspected by many, viz. to perform in some measure the same office for the support of the vegetable life, that the lungs of animals do, for the support of the animal life ; plants > very probably drawing through their leaves some part of their nourishment from the air." p. 326. A little further on he adds, " And may not light also, by freely entering the expanded surfaces of leaves and flowers, contribute much to the ennobling the principles of vegetables ?" p. 328. (84) (84) [The surfaces of most leaves contain a large number of small whitish points, scarcely apparent to the naked eye, but ea- sily distinguished with a glass. These points were called cor tical glands, by Saussure,and evaftorating ftores, by Hedwig. On examination, they are found to consist of small fissures, sur- rounded by areas. According to M. Jurine, a microscopic anat- omist of Geneva, almost all leaves are penetrated with a great number of these apertures. Their size varies in different plants, Thus in the Orchis and Lily kind, they are very large ; in the Jessamine and Oak, they are very small. Leaves are unequally provided with them ; some having pores on both surfaces, others only on one, while some are even destitute of them. These pores which contain air only, are surrounded by a pair of cells, which Jurine denominates conjugate utricles, and which contain a greenish fluid, in common with the other cells of the leaf. Through these pores and utricles, the communication appears to he kept up between the external air and the juices of the leaf.] PURIFICATION OF AIR Next in order of time to those of Hales follow the ex- periments of Bonnet. We have already detailed his ob- servations on the power of leaves to imbibe moisture ; whence it is ascertained that plants are furnished with a system of cuticular absorbents, which carry fluids into their sap-vessels, so as to enable them in some degree to dispense with supplies from the root. With respect to the effects of air upon leaves, this ingenious philosopher has not been equally successful. He is recorded as the discoverer of the expiration of plants, but it appears from his work that he merely observed the bubbles of air which cling to leaves, dead as well as living, and indeed to any other body, when immersed in water and exposed to the light of the sun. He found these bubbles disap- peared in the evening, and returned again when the sun shone, and he faithfully reports that by their attachment to the surfaces of leaves, the latter were rendered more buoyant, and rose in the water; a sure proof that the air had not previously existed, in the same volume at least, in the substance of those leaves. Accordingly, Bonnet concluded that the latter, in imbibing the sur- rounding water, left the air which had been contained in the water, and that this liberated air became visible from being warmed and rarefied by the sun. This was as near the truth as Bonnet could come, it not being then known that light has a power of separating air of a pecu- liar kind, carbonic acid gas, from water. I find no indi- cations in his work of his having had any idea of leaves absorbing air and giving it out again ; still less of their affecting any change in its properties. BY LEAVES. 167 Dr. Priestley was the first who suggested this last- mentioned quality in vegetables. He ascertained their power of absorbing carbonic acid gas, denominated by him fixed air, and giving out oxygen gas, or pure re- spirable air. It was also his opinion that leaves imbib- ed the former by their upper, and gave out the latter by their under surface. He found some aquatic of marsh plants extremely powerful in this respect, es- pecially the Willow-herb or Epilobium, and the Confer- va, a minute branching cotton-like vegetable which grows in putrid water, and the production of which, in water become foul from long keeping on ship-board, Dr. Priestley judged to operate principally in restoring that fluid to a state fit for use. Dr. Ingenhousz, pursuing Dr. Priestley's inquiries, found light to be necessary to these functions, and that, in the dark, leaves gave out a bad air. He observed moreover that fruits and flowers almost invariably gave out a bad, or carbonic, air, but more especially in the dark. He probably carries his ideas of the deleterious effects of this air on animal life, too far; for no mischief has ever happened, as far as common experience goes, to persons sleeping in apple or olive chambers, neither do the inhabitants of the confined huts inCovent-garden mar- ket apparently suffer, from living day and night among heaps of drying herbs. Mischiefs have unquestionably arisen from flowers in a bed-room, or any other confined apartment, but that is to be attributed to their perfumed effluvia. So the bad effects, observed by Jacquin, of Lobe- lia longiflora on the air of a hot-house, the danger incur- red by those who sleep under the Manchineel-tree, Hip- 168 EFFECT OF LIGHT UPON PLANTS. pomane Mancinella, or, as it is commonly believed, under a Walnut-tree, are probably to be attributed as much to poisonous secretions as to the air those plants evolve. Dr. Ingenhousz introduced leaves into glass jars filled with water, which he inverted in a tub of the same water, and placed the whole together in the sun-shine. From their under sides came streams or bubbles of air, which collected in the inverted bottom of each jar. The air thus procured proved oxygen gas, more or less pure. The Nymphaa alba, Engl. Bot. t. 160, affords an ex- traordinary abundance of it. Dr. Ingenhousz observed plants to be very various in their mode of emitting these bubbles, but it was always uniform in the same species. Air collected from water placed in similar circumstances without plants, proved not oxygen, but much worse than common air, viz. carbonic acid gas, which follow- ing chemists have confirmed, and which we have already mentioned. Ingenhousz also found the air collected from plants under water in the dark worse than common air, especially that from walnut-leaves ; which confirms the common opinion, above alluded to, respecting this tree. Plants purify air very quickly. A vine-leaf in an ounce phial of carbonic acid gas, that immediately extin- guished a candle, placed in the sun, without water, changed it to pure respirable air in an hour and half. Dr. Priestley found plants to alter even unmixed inflam- mable air, or hydrogen, especially the Epilobium hirsu- tum, if I mistake not, and Polygonum Hydropiper. Succulent plants are found to afford most air, in con- sequence of the abundance of their Cellular Integument, EFFECT OF LIGHT UPON PLANTS. 1$9 •r Parenchyma, in which, as I have hinted in the fourth chapter, the chemical operations of the leaves are per- formed. That Light has a very powerful effect upon plants, has long been known, independent of the remarks of Hales or Ingenhousz. The green colour of the leaves is owing to it, insomuch that plants raised in darkness are of a sickly white. It has even been observed that when light is admitted to the leaves through different glasses, each tinged of a different prismatic colour, the plant is paler in proportion as the glass approaches nearer to vio- let. The common practice of blanching Celery in gar- dens, by covering it up from the light, is an experiment under the eyes of every one. This blanching of plants is called by the French etiolation, and our chemists have adopted the term, though I think they err in de- riving it from Hoile, a star. When blanched plants are brought into the light, they soon acquire their natural green colour, and even in the dark they are green, if exposed to the action of hydrogen gas. Tulip and Crocus flowers have long ago been observed by Senne- bier to be coloured even in the dark, apparently be- cause their colour depends on a different principle from the green of leaves. Light acts beneficially upon the upper surface of leaves, and hurtfully upon the under side ; hence the former is always turned towards the light, in whatever situation the plant may happen to be placed. Trees nailed against a north wall turn their leaves from the wall, though it be towards the north, and in direct oppo- x 1T0 TURNING OF LEAVES TO THE LIGHT sition to those on a southern wall over against them*. Plants in a hot-house all present the fronts of their leaves, and this influences even the posture of the branches to the side where there is most light, but neither to the quarter where most air is admitted, nor to the flue in search of heat. If the branches of a trained fruit-tree in full leaf be disturbed in their position, the leaves re- sume their original direction in the course of a day or two. The brighter the day, the more quickly is this accomplished. If the experiment be often repeated, they continue to turn, but more weakly, and are much injured by the exertion. Black spots appear about the veins on their under sides, and the cuticle scales off. Succulent leaves, though so thick and firm as many of them are, have been observed to be peculiarly sensible to light, while other plants, as Mallows, according to Bonnet, arc much less so. The Miseltoe, Viscum al- bum, Engl. Bot. t. 1470, the two sides of whose leaves are alike in appearance, and both equally, in general, presented to the light, are not found to turn upon any change in the posture of the branch. Neither do up- right sword-shaped leaves alter their position, because in them both sides must be presumed to perform the same functions with respect to light as well as air. Mr. Calandrini found vine-leaves turned to the light when separated from the stem and suspended by a thread. Of this any one may be easily satisfied, provid- ed the experiment be made with sufficient care and del- icacy. It is important, as demonstrating the turning to be accomplished by an impression made on the leaf it- self, and not upon its footstalk. TURNING OF FLOWERS TO THE LIGHT. 171 Nor is this effect of light peculiar to leaves alone. Many flowers are equally sensible to it, especially the compound radiated ones, as the Daisy, Sun-flower, Mar- igold, &a In their forms Nature seems to have de- lighted to imitate the radiant luminary to which they are apparently dedicated, and in the absence of whose Yearns many of them do not expand their blossoms at all. The stately Annual Sun-flower, Helianthus annuus, displays this phoenomenon more conspicuously on account of its size, but many of the tribe have greater sensibility to light. Its stem is compressed in some degree, to facili- tate the movement of the flower, which, after following the sun all day, returns after sun-set to the east, by its natural elasticity, to meet his beams in the morning. Dr. Hales thought the heat of the sun, by contracting the stem on one side, occasioned the flower to incline that way ; but if so, it would scarcely return completely at night. There can be no doubt, from the observation of other similar flowers, that the impression is made on their radiated florets, which act as wings, and seem con- trived chiefly for that purpose, being frequently destitute of any other use. A great number of leaves likewise follow the sun in its course ; a clover-field is a familiar instance of this. Of all leaves those of pinnated leguminous plants are found most affected by light, insomuch that it appears, in several cases, the sole cause of their expansion, for when it is withdrawn they fold over each other, or droop, as if dying ; and this is called by Linnaeus the Sleep of Plants, who has a dissertation on the subject in his Amoznitates Academics. The term Sleep may not 1M SLEEP OF PLANTS. really be so hyperbolical as at first sight it seems, for the cessation of the stimulus of light, and of the consequent restrained position of the leaves, may be useful to the vegetable constitution, as real sleep is to the animal, Another purpose is answered by the nocturnal folding of some leaves, that they shelter their flowers from the dew, the advantage of which we shall explain hereafter. Some pinnated leaves display a more extraordinary sensibility, not merely to light, but to the touch of any extraneous body, or to any sudden concussion, as those of Mimosa sensitiva, and pudica ; Oxalis sensitiva, and Smithia sensitiva, Ait. Hort. Kew. v. 3,t. 13. An im- pression made even in the most gentle manner, upon one of their leaflets, is communicated in succession to all of them, evincing an exquisite irritability, for it is in vain to attempt any mechanical solution of this phcenomenon. One of this tribe, Hedysarum gyrans, has a spontaneous motion in its leaves, independent of any external stimu- lus, even of light, and only requiring a very warm still atmosphere to be performed in perfection. Each leaf is ternate, and the small lateral leaflets are frequently mov- ing up and down, either equably or by jerks, without any uniformity or cooperation among themselves. It is difficult to guess at the purpose which this singular ac- tion is designed to answer to the plant itself; its effect on a rational beholder cannot be indifferent. The chemical actions of light, heat, and the compo- nent parts of the atmospheric air, upon leaves, and, where the latter are wanting, on the green stems of plants, are now, as far as concerns ali plants in common, tolerably well understood. The observations and ex ACTION OF LEAVES ON THE ATMOSPHERE. 1*3 periments of Priestley and Ingenhousz have been con- firmed, extended in a variety of ways, or explained on the principles of improved chemistry, by Dr. Percival and Mr. Henry in England, Dr. Woodhouse in Ameri- ca, and M. Sennebier and M. Theodore de Saussure, as well as various other philosophers, on the continent of Europe. It is agreed that in the day-time plants imbibe from the atmosphere carbonic acid gas, (which was for- merly called fixed air, and is an union of oxygen and carbon), that they decompose it, absorb the carbon as matter of nourishment which is added to the sap, and emit the oxygen. So they absorb the same gas from water, when it is separated from that fluid by the action of light. The burning of a candle, or the breathing of animals, in confined air, produces so much of this gas, that neither of these operations can go on beyond a cer- tain time, but the air so contaminated, serves as food for vegetables, whose leaves, assisted by light, soon restore the oxygen, or, in other words, purify the air again. This beautiful discovery, for the main principles of which we are indebted to the celebrated Dr. Priestley, shows a mutual dependance of the animal and vegetable kingdoms on each other, which had never been suspected before his time. Comparative experiments upon the lower tribes of these kingdoms have not yet been made, but they would probably afford us a new test for distin- guishing them. The air so copiously purified by a Con- fervq, one of the most inferior in the scale of plants, may he very extensively useful to the innumerable tribes of animated beings which inhabit the. same waters. The abundant air-bubbles which have long ago given even a 174 CHEMICAL ACTION OF botanical name to one supposed species, Conferva bull§- sa, are probably a source of life and health to whole na- tions of aquatic insects, worms and polypes, whenever the sun shines. In the dark, plants give out carbon and absorb oxy- gen : but the proportion of the latter is small, compared to what they exhale by day, as must likewise be the pro- portion of carbon given out; else the quantity of the lat- ter added to their substance would be but trifling, es- pecially in those climates where the proportion of day to night is nearly equal, and which, notwithstanding, we know to be excessively luxuriant in vegetation. Plants also give out azotic gas : but M. de Saussure is of epinion that this proceeds from their internal substance ; and it appears by his experiments to be rather a sign of disease or approaching decay, than a regular chemical production of their constitution when in health ; for Sennebier found the quantity of oxygen emitted was in proportion to the thickness of the leaf, or quantity of parenchyma. Yet the parenchyma must be in its orig- inal organized state, for when bruised its functions are destroyed. Possibly such an alternation in the functions of vege- tables between day and night may afford a necessary repose to their vital principle, whose share in them we know to be of primary importance. Whatever may happen to plants in the dark, there can be no doubt of their principal business in the oeconomy of nature being what we have described. The most luminous and com- pendious view of the whole subject is given by Dr. Thomson of Edinburgh in the fourth vol. of his Chem LEAVES ON THE ATMOSPHERE. 175 istry, which is well worth the attention of those who wish to enter more deeply into all the various chemical examinations respecting it than suits our purpose. It is only necessary to add a short view of Dr. Darwin's hy- pothesis which Dr. Thomson has not mentioned, proba- bly on account of its insufficiency. That lively writer thought the watery perspiration of leaves, acted upon by light, gave out oxygen for the use of the plant itself, such oxygen being immediately absorbed by the air- vessels. This is by no means adequate to explainany of the phcenomena, but rather contradictory to most of them, and is totally superseded by the observations and experiments of other writers. (85) (85) [Some late inquiries, by Mr. Ellis of Edinburgh, go to prove that vegetating plants at all times, both by day and night consume oxygen from the atmosphere, and produce car- bonic acid in its stead. This carbonic acid appears to be the product of carbon, afforded by the vegetable, and oxygen, con- tributed by the air. Oxygen is also given out in considerable quantities, by plants vegetating in the sunshine ; but this pro- duction, Mr. Ellis considers to be not the result of any vegeta- tive function, but only a subordinate operation accomplished by the direct agency of the sun's rays. The disengagement of ox- ygen by the solar sight, is attended with the production of the green colour in plants. It takes phice only from leaves, and other parts, which acquire this colour. Flowers, fruits, roots, See. whether in the sunshine or in the shade, afford nothing but carbonic acid. Mr. Ellis believes that the production of oxygen from plants, is more than balanced by its consumption, and the formation of carbonic acid; and thus that growing vegetables deteriorate the atmosphere, in a degree which greatly surpasses their power to ameliorate and improve it.] 176 CHEMICAL ACTION OR There can be no question of the general purpose an- swered to the vegetable constitution by diese functions of leaves. They confirm Mr. Knight's theory of vege- tation, who has proved that very little alburnum or new wood is secreted when light is kept from the leaves. They also help us to understand how essential oils may be produced, which are known, as well as sugar, to be composed of oxygen, hydrogen and carbon in different proportions. We can now have a general idea how the nutritious sap, acted upon by all the agents above mentioned during its stay in the-cellular substance of the leaf, and returned from thence impregnated with them into the bark, may prove the source of increase, and of peculiar secretions, in the vegetable frame. That por- tion of sap sent to the flower and fruit undergoes no less remarkable changes, for purposes to which those curi- ous organs are devoted ; nor is it returned from thence, as from the leaves, to answer any further end. The existence of those organs is still more temporary, and more absolutely limited to their own purposes, than even that of the leaves, from whose secretions theirs are very distinct. But when we attempt to consider how the particular secretions of different species and tribes of plants are formed ; how the same soil, the same atmosphere, should in a leaf of the vine or sorrel produce a whole- some acid, and in that of a spurge or machineel a most virulent poison ; how sweet and nutritious herbage should grow among the acrid crowfoot and aconite, we find ourselves totally unable to comprehend the exist- ence of such wonderful powers in so small and seeming- LEAVES ON THE ATMOSPHERE. 177 ly simple an organ as the leaf of a plant. The agency of the vital principle alone can account for these won- ders, though it cannot, to our understanding, explain them. " The thickest veil," says Dr. Thomson at the end of his chapter on vegetation, " covers the whole of these processes ; and so far have philosophers hitherto been from removing this veil, that they have not even been able to approach it. All these operations indeed, are evidently chemical decompositions and combina- tions ; but we neither know what these decompositions and combinations are, nor the instruments in which they take place, nor the agents by which they are regulated." The vain Buffon caused his own statue to be inscrib- ed " a genius equal to the majesty of nature," but a blade of grass was sufficient to confound his pretensions. Y *•'[ 178 j CHAPTER XVIT. OF THE SEVERAL KINDS OF FULCRA, OR APPENDAGES TO A PLANT. The word Fulcrum, whose proper meaning is a prop or support, has been applied by Linnaeus not only to those organs of vegetables correctly so denominated, such as tendrils, but also to various other appendages to the herbage of a plant, none of which are universal, or essential,nor is there any one plant furnished with them all. I prefer the English term Appendages for these organs in general, to Props, because the latter applies only to one of them. Seven kinds of these are distinguished by Linnaeus, nor do I find it necessary to enlarge that num- ber. 1. Stipula.. The Stipula, a leafy appendage to the proper leaves or to their footstalks. It is commonly situated at the base of the latter, in pairs, and is ex- tremely different in shape in different plants. The most natural and usual situation of the Stipu- las is in pairs, one stipula on each side of the base of the footstalk, as in Lathyrus latifolius, Engl. Bot. t. 1108, whose stipulas are half arrow-shaped, f 115 ; also in Willows, as Salix stipularis, t. 1214, and S. aurita, t. 1487. In Rosa Potentilla, and many gene- ra allied to them, the stipulas are united laterally to the footstalk, / 116. See Potentilla alba, t. 1384. In all these cases they are extrafoliacea, external with respect to the leaf or footstalk ; in others they are in- OF THE FULCRA. 179 trafolicea, internal, and are then generally simple, as those of Polygonum, t. 1382, 756, &c. In a large natural order, called Rubiacea, these internal stipulas in some cases embrace the stem in an undivided tube above the insertion of the footstalks, like those of Po- lygonum just mentioned : in others, as the Coffee, Coffea arabica, and the Hamellia patens, Engl. Bot. t. 24, they are separate leaves between the footstalks, but meeting just above their insertion. The Euro-~\*~ pean Rubiacea have whorled leaves, as Asperula Ga- lium, Rubia, &c. ; but Asperula cynanchica, Engl. Bot. t. 33, has sometimes two of its four leaves so small as to look like stipulas, seeming to form an in- termediate link between such as have whorled leaves and such as have opposite ones with stipulas. The next step from Asperula is Diodia, and then Sperma- coce. In the two last the bases of the stipulas and footstalks are united into a common tube. Some stipulas fall off almost as soon as the leaves are expanded, which is the case with the Tulip.tree, Liriondendron tulipifera ; in general they last as long as the leaves. The absence or presence of these organs, though generally an indication that plants belong to the same natural order and even genus, is not invariably so. Some species of Cistus have stipulas, others none, which is nearly the same with grasses. The stipula in this, one of the most distinct of all natural orders, is peculiar, consisting of an internal white membrane crowning the sheath of their leaf, and clasping the culm. See Phalaris canariensis, Engl. Bot. t. 1310, 180 OF THE FULCRA, . and Lagurus ovatus, t.1334. In Aria carulea, t. 750, a few minute hairs supply its place, while Sesle- ria carulea, t. 1613, and some maritime grasses, have scarcely more than the rudiment of a stipula. Old writers call this organ in grasses by a peculiar name ligula, and others denominate it membrana foliorum, but both terms are superfluous. A curious instance of stipulas supplying the place of leaves is observable in Lathyrus Aphaca, t. 1167, which has only one or two pair of real leaves on the seedling plants, and those soon disappear, serving chiefly to prove, if any proof were wanted, that the rest are true stipulas. Remarkably scariose or dry membraneous stipulas are seen in Illecebrwn Paronychia, Fl. Grac. t. 246, and in the genus Pinus. 2. Bractea. The floral leaf, a leafy appendage to the flower or its stalk. It is of a variety of forms, and sometimes green, sometimes coloured. The Lime- trees, Tilia europaa, f. 117', t. 610, and parvifo- lia, t. 1705,have a very peculiar oblong pale floral leaf, attached to the flower-stalk. (86) The Lavenders,/ 118, see Curt. Mag. t, 400 and 401, have coloured bracteas, and the Purple-topped Clary, Salvia Hor- minum, Fl. Grac. t. 20, exhibits a gradation from the proper leaves to green bracteas, and from them to coloured ones, which last are barren, or unaccompa- nied by flowers. Hence I am induced to believe this x "Not leSo i -■-. i.irkable in the Tilia Americana, Lime tree, ■ "I OR APPENDAGES OF PLANTS. 181 plant a mere variety of *S*. viridis, t. 19, all whose bracteas are green and fertile; Bartsia, alpina, Engl. Bot. t. 361, and Melampyrum arvense, t. 53, display an elegant transition from leaves to coloured bracteas. The Orchis tribe have green leafy bracteas, different in size in different species. A most beautiful large and coloured bractea is produced in Mussanda fron- dosa, Hort. Mai. v. 2, t. 18, from one of the teeth of the calyx, also in M. glabra of Willdenow, and two new species brought from America by Mr. John Fra- ser. Spinous bracteas of a curious construction guard the calyx in Atractylis cancellata, f. 119. Linnaeus observes that no bracteas are to be found in the class Tetradynamia. The ochrea of Rottboll, Willdenow's Principles of Botany, 50, which enfolds the flower-stalks in Cype- rus, see Engl. Bot. t. 1309, seems to me a species of bractea. 3. Spina, f. 120. A Thorn. This proceeds from the wood itself, and is either terminal like Hppophae rhamnoides, Engl. Bot. t. 425, Rhamnus catharticus, t. 1629 / or lateral as Cratagus (or Mespilus) Crus- galli, (87) tomentosa, parvifolia, &c. Linnaeus observes that this sometimes disappears by culture, as in the Pear-tree, Pyrus sativus which when wild has strong thorns ; hence he denominates such cultivated plants tamed, or deprived of their nat- ural ferocity. Professor Willdenow, Principles of (87) [A very common species of thorn .] 182 % OF THE FULCRA, Bot. t. 270, considers thorns as abortive buds, and thence very ingeniously and satisfactorily accounts for their disappearance whenever the tree receives more nourishment. The permanent footstalks of the Gum Tragacanth shrub, Astragalus Tragacantha, are hardened into real spines, as are the flower-stalks in Pisonia, as well as the stipulas of Xanthium spinosum and the Mimosa. —Linn. Mss. 4. Aculeus,f 121, a Prickle, arises from the bark only, and comes off with it, having no connection with the wood, as in Rosa, Rubus (the Bramble Raspberry, fccc.),and Zizyphus, Willd. Sp. PL v. 1, 1102. This is not liable to disappear by culture, being very distinct in nature from the last. 5. Cirrus, t. 9,f. 122. A Tendril. This is indeed properly called a fulcrum or support, being intended solely to sustain weak and climbing stems upon more firm and sturdy ones. By its means such climbers often reach, in tropical forests, to the summits of lofty trees, which they crown with adventitious blossoms. Tendrils or claspers when young are usually put forth in a straight direction ; but they presently become spiral, making several circumvolutions, by which they take hold of any thing in their way, and then as- sume a firmer texture. After accomplishing a cer- tain number of turns in one direction, some tendrils have a power of twining subsequently the contrary way ; many of them moreover are branched or com- OR APPENDAGES OF PLANTS. 18S pound, so that the chances of their meeting with a support are multiplied.(88) The Vine, Vitis vinifera, the various species of Passion-flower, and the Pea or Vetch tribe afford good examples of spiral tendrils^ The Virginian Creeper Hedera, or, as it ought to be called, Vitis quinquefolia, has branched tendrils, whose extremities adhere to the smoothest flint, like the fibres of Ivy. Gloriosa superba,f. 76, Andr. Repos. t. 129, and Flagellaria indica, have a simple spiral tendril at the end of each leaf ; for they belong to the Monocotyledones, the structure of whose whole her- bage is generally of the most simple and compendious (88) [This is commonly the case with such tendrils as fasten their extremities, and then contract themselves into a spiral eoil, thus drawing the plant nearer to the supporting object" The circumstance of the turns being made in opposite direc- tions, is clearly a provision to obviate the twisting of the tendrils which would otherwise take place. Mr. Knight has published, in the Philosophical Transactions for 1812, some experiments, which go to illustrate the laws of the motions of tendrils. A number of trials, made with tendrils of the Vine, Ivy, 8cc. shewed that these organs recede from the light, and tend toward shady or opake bodies in their neigh- bourhood. A plant of the Amfielofisis quinquefolia which was pla- ced in the middle of a greenhouse, pointed its tendrils toward the north or back wall. Another plant of the same species be- ing placed at the east end of the house, presented its tendrils to- ward the west or centre of the house. Being transfened to the west end and exposed to the evening sun, the tendrils turned round, and pointed again to the centre of the house. In another case the tendrils were sensibly attracted by a piece of d;irk col- oured paper placed near them, while a pane of glass did not pro- duce on them the least effect.] 184 OF THE FULCRA, kind.(89) The flower-stalks of Cardiospermum Halica- eabum bear tendrils ; but a most singular kind of ten- dril, if it may so be called, which certainly has a right to the name oi fulcrum, is found in the Annona hex- apetala, Linn. Suppl. 270. The flower-stalk of this tree forms a hook, and grasps the neighbouring branch, serving to suspend the fruit, which is very heavy, re- sembling a bunch of grapes, and indicates the plant in question to be either a Michelia or an Uvaria. 6. Glandula, a Gland, is defined by Linneus as a little tumour discharging a fluid. Such are abundant on the stalk and calyx of a Moss Rose} OF THE 1 ULCRA. the species of Myosotis, which all botanists before him had either confounded under M. scorpioides, Engl. Bot. t. 480, or else separated upon vague principles. Some species of Galium are admirably characterized by the bristles of their leaves, or of parts of their leaves, being hooked backward or forward. Wc therefore accept the272d maxim of Linnaeus's Philo- sophia Botanica with that limitation which he himself has allowed in his commentary upon it. " The Pu- bescence," says he, " is a ridiculous distinction, be- ing for the most part effaced by culture." After quo- ting examples, he concludes : " We are therefore not to have recourse to the hairiness or spines of plants but in case of absolute necessity." Such necessity every botanist will allow to have existed in the Men- tha and in Myosotis storpioides ; and though the de- gree oi pubescence varies from culture, and even its structure be changeable, as in Hedypnois hispida, Engl. Bot. t. 554, and hirta,-t.*55$, its direction is I believe as little liable to exception as any character that vegetables present- t 1*7 ] CHAPTER XVIII. UF THE INFLORESCENCE, OR MODE OF FLOWERING, AND ITS VARIOUS FORMS. Inflorescence, inflorescentia, is used by Linnaeus to express the particular manner in which flowers are sit- uated upon a plant, denominated by preceding writers the modus florendi, or manner of flowering. Of this the several kinds are distinguished as follows, Verticulus,/! 126. A Whorl. In this the flowers surround the stem in a sort of ring ; though they may not perhaps be inserted on all sides of it, but merely on two opposite ones, as in Dead Nettle, La- nium, Engl. Bot. t. 768—770, Mentha Rubra, t. 1413, and Clinopodium vulgare, t. 1401 ; or even on one side only, as Rumex maritimus, t. 725.(91) The flowers of Hippuris vulgaris, t. 763, are truly inserted in a ring round the stem, f. 127 ; but they are not whorled independent of the leaves, and are therefore more properly, with a reference to the leaves, denomi- nated axillary and solitary. Racemus,/! 128, a Cluster, or Raceme, consists of numerous rather distant flowers, each on its own prop- er stalk, and all connected by one common stalk, as a bunch of Currants, Ribes rubrum, Engl. Bot. t. 1289, nigrum t. 1291, and Orobus sylvaticus, t. 518? ;> 1) [And many other species of Rumex or Dock.l ia» OF THE INFLORESCENCE. A cluster is most generally drooping or pendulous, and the flowers are all expanded nearly at the same time. A compound racemus occurs in Solanum Dulca- mara, t. 565, and an aggregate one, several being gathered together, in Actaa racemosa, (92) Dill. Elth. t. 67 ; but the example of a bunch of Grapes, quoted by Linnaeus for a racemus, appears to me a true thyrsus ; see bejow. Spica,/! 129, a Spike, bears numerous flowers ranged along one common stalk, without any partial stalks, as in Satyrium hircinum, Engl. Bot. t. 34, Orchis bi- folia, t. 22, Plantago major. (93) t. 1558, and media, t. 1559, Potamogeton heterophyHum, t. \285, andfiu- itans, t. 1286 ; but this is so seldom the case, that a little latitude is allowed. Veronica spicata, t. 2, therefore,/! 130, and Ribes Spicatum, t. 1290, as well as the Common Lavender, Lavandula Spica, are suffi- ciently good examples of a spike, though none of them has entirely sessile flowers ; and Linnaeus uses the term in numerous instances where it is still less correctly applicable. A spike generally grows erect. Its mode of expansion is much more progressive than that of the raceme, so that a long period elapses be- tween the fading of the lowest flowers and the open- ing of the upper ones. The flowers are commonly all crowded close together, or if otherwise, they form separate groups, perhaps whorls, when the spike is (92) [Called in the United States, Black Snake Root.] (93) [Greater Plantain.] OF THE INFLORESCENCE. 189 said to be either interrupted, or whorled; as in some Mints. In Sanguisorba officinalis the spike begins flowering at the top. See Capitulum below. A compound spike is seen in Lavandula vinnata, Curt. Mag. t. 401,and L. abrotanoides of Willdenow. Spica secunda, a spike whose flowers lean all to one side, occurs in Nardus stricta, Engl. Bot. t. 290. Spicula, f. 131, a Spikelet, is applied exclusively to grasses that have many florets in one calyx, such florets, ranged on a little stalk, constituting the spike- let, which is therefore a part of the flower itself, and not of the inflorescence; see Poa aquatica, t. 1315, .fiuitans, t. 1520, Briza minor, t. 1316, &c. Corymbus, f 132, a Corymb, is a spike whose partial flower-stalks are gradually longer as they stand lower on the common stalk, so that all the flowers are nearly on a level, of which Spiraa opulifolia, a common shrub in gardens, is an excellent specimen. The Lin- naean class Tetradynamia exemplifies this less perfect- ly, as Cardaminepratensis, Engl. Bot. t. 776, Cheiran- thus sinuatus, t. 462, and the common Cabbage, Bras- sica oleracea, t. 637, in which the corymbus of flowers becomes a racemus of fruit, as happens also in that sec- tion of the Veronica, entitled by Linnaeus corymboso- racemosa. The flowers of YarrowJt/! 133, Achillea, t. 757,and 758, and several others of the compound class, as well as the Mountain-Ash, t. 337, grow in a corym- bose manner, though their inflorescence may not come exactly under the above definition. It is worthy of re- mark that Linnaeus in that definition uses the word spica, not racemus, nor has he corrected it in his own copy 190 OF THE INFLORESCENCE. oi Phil. Bot. p. 41, though he has properly altered a slip of the pen in the same line,petiolis, topeduncidis.* This shows he did not restrain his idea of a spike absolutely to sessile flowers, but admitted that ex- tended signification which nature justifies. Many plants acquire partial stalks as the fruit advances to- wards maturity. Fasciculus,,/! 134, a Fascicle, is applied to flowers on little stalks, variously inserted and subdivided, collected into a close bundle, level at the top, as the Sweet William, Dianthus barbatus, Curt. Mag. t, 207, and D. Armeria, Engl. Bot. t. 317.(94) Capitulum,,/! 135, a Head or Tuft, bears the flowers sessile in a globular form, as Statice Armeria, t. 226, Adoxa Moschatellina, t. 453, and Gomphrena globosa, the Globe Amaranthus of the gardens. Perhaps the inflorescence of Sanguisorba officina- lis, t. 1312, might be esteemed a capitulum, because its upper flowers come first to perfection, as in Adoxa, which seems contrary to the nature of a spike; but it does not appear that all capitate flowers expand in the same way, and Sanguisorba canadensis has a real spike, flowering in the usual manner, from the bottom upwards. So Allium descendens, Curt. Mag. t. 251, opens its upper, or central, flowers first, con- * It might be expected from the numerous learned editors and copiers of this and other works of Linnaeus, that they should correct such manifest errors as the above, which any tyro might perceive. (94) [The Dianthus Armeria is a native.] OF THE INFLORESCENCE. 191 trary to the usual order in its genus ; both which in- stances prove such a diversity to be of small moment. Um b e l l a, an Umbel, for which some authors retain the obsolete old English name of Rundle. In this seve- ral flower-stalks, or rays, nearly equal in length, spread from one common centre, their summits form- ing a level, convex, or even globose surface, more rarely a concave one. When each ray is simple and single-flowered, it is called a simple umbel,/! 136, as those of Allium ursinum, Engl. Bot. t. 122, Ivy, t. 1267, Primula veris, t. 5, farinosa, t. 6, elatior, t. 513, and Eucalyptus resinifera, Exot. Bot. t. 84.(95) In a compound umbel each ray or stalk mostly bears an umbellula, or partial umbel, as Athamanta Libano- tis, Engl. Bot. t. 138. This is usually the case in the very natural order of plants called unbelliferous, f. 138, to which the last-mentioned, as well as the common Carrot, Parsnep, Parsley, Hemlock, &c. be- longs. A few only of this order have simple umbels, as Hydrocotyle vulgaris, t. 751, and the curious Astran- tia, f 137, and Enocalia, Exot. Bot. t. 76-—79. In Euphorbia the umbel is differently compounded, con- sisting of 3, 4, 5 or numerous rays, each of which is repeatedly subdivided, either in a threefold or forked manner. See Engl. Bot. t. 883, 959, &c.(96) (95) [Fine examples of the Simple Umbel occur in the Silk- wepds, Asclepias Syriaca, fiurfiurascens, tuberosa, &c] (96) [An Umbel is said to be .radiate, when the outer petals of the external flowers are larger and longer than the rest ; it is 198 OF THE INFLORESCENCE. Cyma,/ 139, a Cyme, has the general appearance of an umbel, and agrees with it so far that its common stalks all spring from one centre, but differs in having those stalks variously and alternately subdivided. Examples are found in Viburnum, Engl. Bot. t. 331, 332, and the common Laurustinus, as also in Sam- bucus, Elder, t. 475, 476. This mode of inflores- cence agrees with a corymbus also in general aspect, but in the latter the primary stalks have no common centre, though the partial ones may sometimes be um- bellate, which last case is precisely the reverse of a cyma. Panicula,/! 140, a Panicle, bears the flowers in a sort of loose subdivided bunch or cluster, without any or- der. When the stalks are distant, it is called diffusa, a lax or spreading panicle, as in Saxifraga umbrosa, t. 663, so frequent in gardens under the name of Lon- don Pride, and S. Geum, t. 1561, but particularly in many grasses, as the common cultivated Oat, and Avena strigosa, t. 1266 ; in this tribe the branches of the panicle are mostly semiverticillate ; see Aira aquatica, t. 1557. A divaricated panicle is still more spreading, like those of Prenanthes muralis, t. 457, and Spergula arvensis, t. 1*535 ; the last being dichotomous or forked. A dense or crowded panicle, coarctata, is observable in Milium lendigerum, t. 1107, and Agrostis stolonifera, t. 1532, but still more re- markably in Phelum paniculatum, t. 1077, whose in- fioscular, when the flowers are alike in size. See Aggregate Flowers.] OF THE INFLORESCENCE. 19.1 florescence looks, at first sight, like a cylindrical spike, but when bent to either side, it separates into branch* ed lobes, constituting a real panicle. (97) Thyrsus,/ 141, a Bunch, is a dense or close panicle, more or less of an ovate figure, of which the Lilac, Syringia vulgaris, Curt. Mag. t. 183, Tussilago hyb- rida and Petasites, Engl. Bot. t. 430, 431, are exam- ples cited by Linnaeus. I presume likewise to con- sider a bunch of grapes, Vitis vinifera, as a true thyr- sus, to the characters and appearance of which it cor- rectly answers. Its ultimate terminations are some- times obscurely umbellate, especially while in blos- som, which is no objection here, but can never be the case in a racemus, whether simple or compound. See Racemus. Of simple flower-stalks, whether solitary or cluster- ed, radical or cauline, axillary, lateral or terminal, we have already spoken. Linnaeus remarks that the most elegant specific characters are taken from the inflorescence. Thus the Apple, Engl. Bot. t. 179, and the Pear, form two species of Pyrus, so far at least a most natural genus, the former of which bears an umbel, the latter a co- rymb. Pyrola unifiora, t. 146, secunda, t. 517, and umbellata, Curt. Mag. t. 778, are admirably distin- guished by their several forms of inflorescence. (97) [A Panicle leaning one way, Panicula tecundn, is found m Dactylis glomcrata, or Orchard Grass.] A A I 194 ] CHAPTER XIX. OF THE FLOWER AND FRUIT. Having examined the general structure and external form of plants, we now come to more important and even essential, though more transitory organs—the flow- er and fruit, or parts of fructification. By these each spe- cies is perpetually renewed without limits, so far at least as the observation of mankind has reached ; while, as we have already mentioned, all other modes of propaga- tion are but the extension of an individual, and sooner or later terminate in its total extinction. . Nothing can be more happy than the Linnaean defini- tion of these organs ; Phil. Bot. 52. " The fructifica- tion is a temporary part of vegetables, destined for the reproduction of the species, terminating the old individ- ual and beginning the new." Pliny had long ago beautifully said, that " blossoms are the joy of trees, in bearing which they assume a new aspect, vieing with each other in the luxuriance and va- riety of their colours." Linnaeus has justly applied this to plants in general, and, improving upon the idea, he considers their herbage as only a mask or clothing, by no means indicative of their true nature or character, which can be learned from the flower and fruit alone. Mr. Knight has traced his central vessels, by which the sap is conveyed from the root, in the flower and fruit. On the returning sap into the bark of these parts he has not been able to make any distinct observation ; OF THE FLOWER AND FRUIT 195 but he has determined that no matter of increase is fur- nished from the flowers or their stalks, as from leaves, to the part of the branch below them, nor indeed to any other part, Phil. Trans, for 1801, p. 340. There can be no doubt that certain parts of the flower, which we shall presently describe, perform functions respecting air and light analogous to those of leaves, but entirely subservient to the benefit of the flower and fruit. Their secretions, formed from the returning sap, are confined to their own purposes. As soon as these are accomplish- ed, a decided separation of vessels takes place, and the ripe fruit, accompanied perhaps by its stalk, falls from the tree. Dr. Hales tried in vain to give any flavour to fruit by the most penetrating and volatile fluids conveyed through the sap-vessels ; for the laws of secretion are absolute in the organs of the flower, and their various re- suits are, if possible, more strikingly distinct than even those we have contemplated in the leaves. It is scarcely necessary to repeat that the fructification is essential to vegetables. A plant may be destitute of stem, leaves, or even roots, because if one of these parts be wanting, the others may perform its functions, but it can never be destitute of those organs by which its spe- cies is propagated. Hence, though many individual plants may be long without blossoms, there are none, so far as nature has been thoroughly investigated, that are not capable, in favourable circumstances, of producing them, as -well as seeds ; to whose perfection the bios- soms themselves are altogether subservient. Linnaeus distinguishes seven parts of fructification, some of which are essential to the verv nature of a flow- 196 OF THJ3 l'ARTS OF FRUCTIFICATION. er or fruit, others not so indispensably necessary, and therefore not universal. I. Calyx, the Calyx or Flower-cup, generally resem- bling the leaves in texture and colour, and forming the outermost part of a flower. This is not essential, and is often absent. II. Corolla, the Corolla, or more delicate coloured inter- nal leaf or leaves, properly petals, of a flower, likewise not essential, III. Stamen, or Stamina, the Stamen or Stamens, com- monly of a slender or thread-like form, bearing some kind of knob or cellular body, and ranged internally with respect to the Corolla, These are essential. IV. Pistillum, or Pistilla, the Pistil, or Pistils, in the centre of the flower, consisting of the rudiments of the fruit, with one or more prgans attached to them, and, of course, essential. V. Pericarpium, the Seed-vessel, of a pulpy, woody, or leathery texture, enclosing the seeds, but wanting in many parts. VI. Semen, the Seed, the perfecting of which is the sole end of all the other plants. VII. Receptaculum, the Receptacle, basis or point of connecuon. Ti-is must necessarily be present in some form or other, DIFFERENT KINDS OF CALYX. 197 J. Calyx. The Flower-cup, or more correetly the external covering of the flower, when present, was originally divided by Linnaeus into seven kinds, some of which are more justly so denominated than the oth- ers, and I have ventured to make an alteration in his list. J. Perianthium,f 142. Calyx, properly and common- ly so called, when it is contiguous to and makes a part of the flower, as the five green leaves which en- compass a Rose, including their urn-shaped base ; the two green bristly ones which enfold the bud in Glau- cium luteum, Fl. Brit. Engl. Bot. t. 8 j the tubular part, comprehending the scales at its base, in the Pinks, t. 61, 62, or the globular scaly cup, in Centau- rea, t. 56. The Tulip, t. 63, is a naked flower, having no calyx at all.(98) (98) [Some of the most remarkable forms of the calyx are Ventricosus, inflated, when it appears swelled or distended, as in Cucubalus Behen, or Campion. Prismaticus, prismatic, with sharp, somewhat parallel angles, as in Mimulus, or Monkey Flower. Imbricatum or Squamosum, imbricated or scaly. Squarrosum, Squarrose, when the leaflets which compose it, are bent back at the points. Scariosum, Scariose, when the leaflets are hard, thin, and dry. Ciliatum, fringed with hairs or bristles on the margin. Muricatum, Muricated, set with short stiff prickles. Sftinosum, thorny, each leaflet tipped with a thorn, as in thistles. Turbinatum, turbinate, having the figure of a top. Calyculatum, calyculated or doubled, when one calyx appears to be enclosed at its base by another.] 198 OF THE INVOLUCRUM. This part is of an infinite variety of forms in differ- ent genera, being either simple or compound, divided or undivided, regular or irregular. In some instances it is permanent till the fruit is ripe, in others it falls even before the flower is well expanded. Some genera have a double perianthium, as Malva, t. 671, or even a triple one, as Scabiosa, t. 1311. 2. Involucrum, f. 143, Involucre of Professor Martyn ; but I generally retain the Latin termination. This is remote from the flower, and can scarcely be distin- guished clearly from a Bractea. The term was first adopted by Linnaeus, at the suggestion of his friend Artedi, in order to distinguish the genera of umbellif- erous plants, for which purpose the latter deemed the part in question very important. But according to the Jaws which Linnaeus had laid down, the parts of the flower and fruit alone were to afford generic char- acters, and the most sound botanists have ever since kept to this rule, with infinite advantage over less cor- rect ones, however ready to derive ideas respecting the natural habit, and secondary characters, of a ge- nus, not only from the inflorescence and bracteas, but even from the leaves, stipulas, or other parts. Lin- naeus and Artedi, therefore, were obliged to consider the involucra and involucella, the former accompany- ing the general and the latter the partial umbels, as a sort of calyx, and the umbel altogether as one aggre- gate flower, composed of florets united by a common radiated receptacle. Consequently a cyme must be considered in the same light; nor are reasons wanting in support of this hypothesis, which we shall consider OF THE INVOLUCRUM- 199 after having first explained all the parts of fructifica- tion. In Euphorbia, however, the term bractea would surely be more proper than involucrum or involucel- lum, as is evident from a consideration of the inflores- cence of the whole genus, so very different in different species. In E. Peplis, and many others, the flowers are solitary and axillary ; in others again, as E. amygdaloides, Engl. Bot. t. 256, and Characias, t. 442, some flower-stalks are umbellate, some scatter- ed ; and the subdivisions of the umbel in all are ulti- mately forked, that is, of a nature between umbellate and scattered. This genus has, moreover, a proper calyx or perianthium of a most distinct and peculiar nature. Some species of Anemone, a genus destitute of a perianthium, are said by Linnaeus to have an invo- lucrum, as A. Pulsatilla, t. 51, for which the name of bractea would be vastly more correct, though in A. Hepatica, Curt. Mag. t. 10, it is placed so near the flower as to seem a part of it, which, however, is real- lv not the case. - * The name of Involucrum is applied by Gleditsch to the membrane covering the fructification of ferns, / 144, 145 ; nor have I, in studying this part with pe- culiar attention, in order to reform the genera of these plants, see Tracts relating to Natural History, p. 215, found reason to contrive any new appellation. My learned friends Willdenow and Swartz have judged otherwise, calling this membrane the indusium, or covering ; which seems to me altogether superfluous. See its various forms in Engl. Bot. t. 1458—60, 1150, 1159, 1160, &c. 200 OF THE AMENTUM. 3. Amentum, f. 146. Catkin, denominated by authors before Linnaeus julus, nucamentum, or catulus ; con- sists of a common receptacle of a cylindrical form be- set with numerous scales, each of which is accompa- nied by one or more stamens or pistils, so that the whole forms an aggregate flower.(99) The recepta- cle itself and the bases of the scales are firmly united, and. the whole catkin falls off entire, except that in some instances the upper part of each scale withers away, as in the Willow genus, Salix, Engl. Bot. t. 1388—90, 1402—4, &c, the seed-vessels in that genus being quite distinct from the scales. In others, the whole scale remains, enlarges, hardens, and pro- tects the seed, as in Pinus, the Fir tribe. Such is the case with catkins of fertile flowers, which are necessa- rily permanent till the seed is ripe ; barren ones fall as soon as the stamens have performed their office. Every catkin consists generally of either one kind of flower or the other. There are few certain and inva- riable instances of stamens and pistils in the same cat- kin, that circumstance occurring chiefly in a few spe- cies of Salix and Carex ; nor fs Typha, t. 1455—7, an exception to this. Examples of barren-flowered catkins are seen, not only in Salix and Pinus, but in several plants whose fertile or fruit-bearing flowers are not catkins, such as the Walnut, and, unless I am much mistaken, the Hasel-nut, t. 723. Each nut or seed of the latter has a permanent coriaceous calyx of (99) [The Ament or Catkin is the most common inflorescence of our Forest trees ; as the Oak, Walnut, Chesnut, Birch, Alder, 8cc] OF THE SPATHA AND GLUME. ZQl its own, inadvertently called by Gaertner an involu- crum, though he considers the whole as an amentum, which this very calyx proves it not to be.* Humu* lus, the Hop, t. 427, has a catkin for the fertile flower only. 4. Spatha,f. 147. Sheath, a covering which bursts longitudinally, and is more or less remote from the flower. This is exemplified in the Snow-drop, Ga- lanthus nivalis, t. 167, the various species of Narcis- sus, t. 17, 275 and 276, and the Arum, (100) 1.1298, The Spatha of the latter encloses a Spadix, or elon- gated receptacle, common to many flowers, according to the genuine Linnaean idea of this kind of calyx, taken from Palm-trees. In these the Spadix is branched. (101) 5. Gluma,f. 148. Husk, the popular calyx of Grass- es and Grass-like plants, of a chaffy texture. These husks are usually compressed, embracing each other at the base, as in Phleum pratense, t. 1076. Some- times they are ^depressed, flattened vertically, as in Briza, t. 540 and 1316. To the husk belongs the * It appears moreover that Carfiinus, the Hornbeam, has hith- erto erroneously been supposed to have an amentum for the fer- tile flower. The true nature of the covering of the seed, as well as of the common stalk, proves it otherwise. (100) [The spatha of Arum trifihyllum is inflected at the top, and often elegantly striped within. That of Pothoa fcetida ap- pears with its spadix before the leaves.] (101) [The receptacle of Ac or us or Sweet Flag, is a SpadiX; destitute of a Spatha.] BB -0 OF THE PEKICHiETIUM Arista, f. 149, Beard or Awn, a bristle-shaped appen- dage, usually spiral, and possessing the property of an hygrometer. This, however, is not always pres- ent, even in different individuals of the same species. « Unfortunately for the science, On the awn there's no reliance." So says, or rather sings, with more truth than sub- limity, the ingenious author of the Flora Londinensis, fasc. 6, t. 8. The spiral kind of awn is most frequently attached to the Coroll of grasses, which is precisely of the same husky nature as their calyx, and is, by some bota- nists, considered as such. Specimens of gluma muti- ca, beardless husks, are seen in Phalaris canariensis, Engl. Bot. t. 1310, and gluma aristata, awned ones, in Lagurus ovatus, t. 1334, and Stipa pennata, t. 1356. 6. Perichatium, f 150. A scaly Sheath, investing the fertile flower, and consequently the base of the fruit- stalk, in some Mosses. In the genus Hypnum it is of great consequence, not only by its presence, con- stituting a part of the generic character, but by its differences in shape, proportion, and structure, serving frequently to discriminate species. See Engl. Bot. t. ' 1037—9, 1182, 1445—8, &c. ; see also the same part in Neckera,t. 1443, 4. Linnaeus appears by his manuscripts to have intended adding this to the different kinds of calyx, though it is not one of the seven enu- merated in his printed works. Nor is he, surely, cor- rect in allowing it to the genus Jungermannia. The AND VOLVA. 20S membranous part which he there calls perichatium is strictly analagous indeed to the calyptra,f 151,152 b, or veil of real mosses, esteemed by him a kind of ca- lyx ; but as I presume with Schreber, to reckon it rather a corolla, and Hedwig once thought the same, and as Jungermannia has more or less of a real calyx besides,/ 152a, see Engl. Bot. t. 771, &c, I would no longer apply the term perichatium to this genus at all. The part called calyptra being removed from the list, as being a corolla, the perichatium takes its place among the seven kinds of calyx. We lay less stress upon this coincidence than Linnseus might have done, when, according to the fashion of the times, he condescended to distribute his immortal Philosophia Botanica into 12 chapters and 365 sec- tions, and reckoned 6even parts of fructification as well as seven species of calyx. 7. Volva, f 153. Wrapper, or covering of the Fungus tribe, of a membranous texture, concealing their parts of fructification, and in due time bursting all round, forming a ring upon the stalk, as in Agaricus procerus, Sowerb. Fung. t. 190, and A. campestris, the Common Mushroom, t. 305 ; such at least is the original meaning of this term, as explained in the Phil. Bot. ; but it has become more generally used, even by Linnaeus himself, for the more fleshy external cov- ering of some other Fungi, which is scarcely raised out of the ground, and enfolds the whole plant when young, / 154. See Agaricus vohaceus, t. 1, and 204 ORIGIN OF THE CALYX. Lycoperdonfomicatum, t. 198; also the very curious L. phalloides, t, 390, now made a distinct genus by the learned Persoon, under the name of Batarrea phalloides. Linnaeus adopted from Caesalpinus the opinion that the Calyx proceeded from the bark, like the leaves, be- cause of its similarity in colour and texture to those organs. He even refined upon the original idea, and supposed this part to proceed from the outer bark, while the more delicate corolla originated in the liber. What is now known of the physiology of the bark, as explain- ed in several of our preceding chapters, renders this hy- pothesis totally inadmissible. The knowledge of the real use of leaves, see chapter 16, may however throw some light upon that of the calyx. Besides protection of the flower from external injuries, which is one evident use of this part, it ap- pears highly probable that it may often contribute to the growth and strength of the stalk which supports it, as the leaves do to that portion of branch below them. The stalk often swells considerably during the growth of the flower, especially just below the caiyx, becoming more woody, an alteration frequently necessary for the support of the ripening fruit. When the calyx falls very early, as in the Poppy tribe, Papaver and Glaucium, I cannot find that the flower-stalk is subsequently enlarged, nor in any manner altered ; while in genera without num- ber, whose calyx is permanent, the stalk becomes not only more woody, but often considerably thickened. II. Corolla. The Corolla, vulgarly called the leaves of the flower, consists of those more delicate and dila OF THE COROLLA. 205 ted, generally more coloured leaves, which are always internal with respect to the calyx, and constitute the chief beauty of a flower. In the Rose the Corolla is red and fragrant ; in the Violet purple ; in the Prim- rose yellow. This term includes two parts, the Petal, Petalum, and the Nectary, Nectarium. The former is either simple, as in the Primrose, in which case the Corolla is said to be monopetalous, of one petal; or com- pound, as in the Rose, in which it is polypetalous, of several. The Nectary is sometimes a part of the petal, sometimes separate from it. A monopetalous Corolla consists of two parts ; the tube, tubus, the cylindrical part enclosed in the calyx of the Primrose, and the limb, limbus, which is the horizontal spreading portion of the same flower, / 155. The analogous parts of a polypetalous Corol- la, as in the Wall-flower or Stock,/ 156, are named the claw, unguis, f. 157 a, and the border, lamina, b. The Corolla is infinitely diversified in form in dif- ferent genera, whence Tournefort and Rivinus deriv- ed their methods of arrangement. It is called regular when its general figure is uniform, as in the Rose, the Pink, the Columbine, Aquilegia, vulgaris, Engl. Bot. t. 297, and Gentiana Pneumonanthe, t. 20; irregular when otherwise, as the Violet, t. 619, 620, Dead-net- tle, t. 768, and Lathyrus, t. 805 and 1108. An equal Corolla,/ 156, is not only regular, but all its divisions are of one size, like those of the Primrose, t. 5, Campanula, t. 12, or Saxifraga, t. 9 ; an une- qual one,/ 158, is when some segments are alternate- 206 FORMS OF THE COROLLA. ly smaller than the others, as in Butomus, t, 651, or otherwise different, as in Aquilegia. t. 297. It is by no means always necessary, in defining characters of genera, to use these last terms, it being sufficient in general to say that a Corolla is regular in opposition to one that is irregular ; more especially as some species of a genus may possibly have an equal corolla, others an unequal one. The most usual shapes of a monopetalous corolla are campanulata, f. 159, bell-shaped, as in Campanula, t. 12. infundibuliformis, f. 160, funnel-shaped, (102) Pulmo- naria, t. 118. hypocrateriformis, f. 155, salver-shaped, (103) Pri- mula, t. 4. rotata, wheel-shaped, that is salver-shaped with scarce- ly any tube, Borago, t. 36. ringens, f. 161, ringent, irregular and gaping like the mouth of an animal, Lamium, t. 768 ; called by for- mer botanists labiata, lipped. (104) personata, f 162, personate, irregular and closed by a kind of palate, Antirrhinum, t. 129. Those of a polypetalous one are eruciformis, f. 156, cruciform, regular and like a cross, Dentaria, t. 309, and Cheiranthus, t. 462. (102) [Tubular at bottom, but gradually expanding toward the top, as Thorn Apple, Datura.] (103) [Tubular for mo6t of its length, but suddenly expanding into a flat border at top,] (104) [The upper lip of a ringent corolla is commonly smaller, and has the stamens projecting from beneath it. The lower lip is larger and more expanded. When this order is changed, the corolla is said to be reversed."] PHYSIOLOGY OF THE COROLLA. 207 rosacea, rosaceous, spreading like a rose, Dryas, f.^451. papilionacea,f 163, papilionaceous, irregular and spread- ing, somewhat like a butterfly, Lathyrus, t. 1108. The various petals which compose such a flower are distinguished by appropriate names, as vexillum,f 164, standard, the large one at the back ; ala,f. 165, wings, the two side petals ; and carina, f. 166, the keel, consisting of two petals, united or separate, em- bracing the internal organs,/ 167. In Trifolium all the petals are sometimes united into one at the lower part. incompleta, incomplete, when parts, which analogy would lead us to expect, are deficient, as in Amorpha, a pa- pilionaceous flower apparently, but consisting of the vexillum only ; or Rittera of Schreber,/' 168, a ro- saceous one with a single lateral petal, seeming as if four others had been stripped off. It is remarkable that irregular flowers sometimes vary to regular ones in the very same plant, as in Bignonia radicans, Curt. Mag. t. 485 ; and Antirrhinum Lina- ria,f 169, Engl. Bot. t. 658 and 260. Linnaeus was of opinion that the Corolla originated from the Liber or inner bark, as the C ilyx from the out- ' er, but this cannot be defended now the real physiology of the bark is better understood. The whole use and physiology of the Corolla have not yet been fully explained. As a protection to the tender and important parts within, especially from wet, its use in many cases is obvious, but by no means in all. Lin- naeus imagined it to serve as wings, to waft the flower up and down in the air, and so to promote the functions 208 PHYSIOLOGY OF* of the Stamens and Pistils, as will hereafter be describ- ed ; nor is this opinion unfounded. Sprengel has ingeniously demonstrated, in some hun- dreds of instances, how the Corolla serves as an attraction to insects, indicating by various marks, sometimes per- haps by its scent, where they may find honey, and ac- commodating them with a convenient resting-place or shelter while they extract it. This elegant and ingen- ious theory receives confirmation from almost every flower we examine. Proud man is disposed to think that « Full many a flower is born to blush unseen," because he has not deigned to explore it; but we find that even the beauties of the most sequestered wilder- ness are not made in vain. They have myriads of ad- mirers, attracted by their charms, and rewarded with their treasures, which very treasures would be as use- less as the gold of a miser to the plant itself, were they not thus the means of bringing insects about it. The services rendered by such visitants will be understood when we have described all the parts of a flower. Besides the above purposes, I have always conceived the Corolla to fulfil some important office to the essen- tial parts of the flower with respect to air, and especially light. (105) It not only presents itself in a remarkable (105) [The ingenious, but often visionary St. Pierre supposes the corolla to regulate the sun's influence on the fructification of the plant, by reverberating the solar rays upon the anthers and stigma; or in some instances by sheltering them from too intense heat.] THE COROLLA. 209 manner to the sun-beams, frequently closing or drooping when they are withdrawn, but it is so peculiarly distin- guished by beauty or brilliancy of colour, that one can- not but think its functions somewhat different from those of the leaves, even with regard to light itself. Dr. Darwin calls the Corolla the lungs of the stamens and pistils, and with great probability, for they abound in air-vessels (106) But when we consider the elaborate and peculiar secretions of a flower, the elastic and in- flammable pollen, the honey, and the exquisitely volatile perfume, as we know from the curious discoveries of modern chemistry how great a share light has in the pro- duction of such, we cannot but conclude that the petals must be of primary importance with respect to their secretion by its means. Sometimes the Corolla is very short-lived ; sometimes very lasting, even till the fruit is perfected, though most- ly in a faded condition. In double flowers I have ob- served it to be much more durable than in single ones of the same species, as Anemones and Poppies, because, as I conceive, of its not having performed its natural functions, the stamens and pistils of such flowers being obliterated, or changed to petals; hence the vital princi- ple of their corolla is not so soon exhausted as usual. Phil. Trans, for 1788, p. 165. The Corolla, as already observed, is not essential. Whatever its functions may be, they can be occasionally (106) [Flowers uniformly deteriorate the air according to the experiments of Priestley, Ingenhousz, and De Saussure. They consume oxygen, and produce carbonic acid, both in the sun- shine and in the shade.] CC 210 DISTINCTIONS BETWEEN performed by the Calyx perhaps, or even by the Fila- ments of the Stamens ; as those of leaves are, in leafless plants, by the stems. When a flower has only one cov- ering, it is not always easy to say whether that be a Ca- lyx or Corolla. When green and coarse in texture like the former, we call it so, as in Chenopodium, Engl. Bot. t. 1033, and 1721—4, and the natural relationship of this genus to Polygonum, t. 1044, 989, 756, &c, leads us to reckon the same part in the latter a coloured calyx. On the other hand, when the part present is delicate and finely coloured, like the generality of Corollas, we de- nominate it such ; more especially if the plant to which it belongs be allied to others that have a Calyx besides, as in Tulipa, t. 63, allied to Leucojum, t. 621, which has a Spatha. The great Jussieu denominates this part in the Tulip and other liliaceous plants, however beauti- ful, a Calyx. His definition of a Corolla is " that cov- ering of a flower which is invested with the calyx, being very rarely naked ; a continuation of the inner bark of the flower-stalk, not of its cuticle ; not permanent, but mostly falling off with the stamens ; surrounding or crowning the fruit, but never growing united with it ; and having its parts or segments for the most part alter- nate with the stamens, which are equal to them in num- ber." By this rule the tube and six segments of a Nar- cissus, t. 17, 275 and 276, constitute the Calyx, and then surely what Jussieu calls a Crown,/ 1476, and Linnae- us a Nectary, must be allowed the n im of Corolla. On the other hand, the Spatha becomes a Bractea. Con- sequently the whole order of Liliaceous flowers in gene- ral have a coloured Calyx only, which seems hardly ad- COROLLA AND CALYX. 211 missible ; and yet I cannot conceal a recent discovery which strongly confirms the opinion of my acute and candid friend. Two species of a new genus*, found by Mr. Menzies on the West coast of North America, have beautiful liliaceous flowers like an Agapanthus, with three internal petals besides ! Tulbaghia is a similar instance. I must however protest against the idea of the Corolla originating exclusively from therinner bark, as well as of the cuticle not being continued over it, for reasons sufficiently apparent from the former part of this work. It is a Linnaean rule that the Stamens should be oppo- site to the segments of the Calyx, and alternate with the parts of the Corolla. Its author nevertheless seems of opinion that no absolute means of distinction between these two parts can be pointed out, except colour ; of the insufficiency of which he is aware. If however the Corolla performs functions with respect to light which the Calvx does not, and those functions are indicated by its colour, a distinction founded on such a principle is both correct and philosophical. We must then con- clude that in most liliaceous plants, not in all, the two organs are united into one, and indeed the outside is of- ten green and coarse like a Calyx, the inner coloured and delicate ; witness Ornithogalum, t. 21, 130 and 499, Narthecium, t. 535, &c. Linnaeus has the same idea respecting Daphne, t. 119 and 1381, and the analogy is confirmed by Gnidia, which is a Daphne with petals. In Trollius, t. 28, and Helleborus, t. 200 and 613, Lin- * I have lately, in a paper to the Linnaean Society, named this ijenus Broditea, in honour of James Brodie, Esq. F. L. S. 218 <*P THE NECTARY. naeus considers as petals what Jussieu, following Vail- lant, thinks a Calyx. Of these plants we shall soon have occasion to speak again. I cannot but consider as a sort of Corolla the Calyp- tra or Veil of Mosses, which Linnaeus reckoned a Ca- lyx. Schreber, very deep and critical in his inquiries concerning these plants, and Hedwig, so famous for his discoveries among them, were both of this opinion, thougK.the latter seems to have relinquished it. The organ in question is a membranous hood, covering the unripe fruit of these diminutive vegetables, like an ex- tinguisher,/ 151 ; but soon torn from its base, and ele- vated along with the ripening capsule. See Engl. Bot. t. 558, &c. The great peculiarity of this part, whatev- er it be called, consists in its summit performing the of- fice of a stigma, as Hedwig first remarked. In Junger- mannia,f 152, t. 771, &c, the very same part, differing only in usually bunting at the top to let the fruit pass, is named by Linnaeus a perichatium, but very incorrect- ly, as we have already hinted. Whatever office the Petals may perform with respect to air and light, it is probable that the oblong summit of the Spadix in Arum, t. 1298, answers the same pur- pose. When this part has been for a short time expos- ed to the light, it assumes a purplish brown hue, which M. Senebier seems to attribute to the same cause which he thinks produces the great heat observed in this flow- er, the rapid combination of oxygen gas with the carbon of the plant : an hypothesis hardly adequate to explain eilher. Nectarium, the Nectary, may be defined as that part of the Corolla which contains or which secretes honey. AND HONEY. -dlo It is perhaps in effect nearly universal, as hardly a flow- er can be found that has not more or less honey, though that liquor is far from being universally, or even gene- rally, formed by any apparatus separate from the Petals. In monopetalous flowers, as Lamium album, the Dead Netde, t. 768, the tube of the corolla contains, and probably secretes the honey, without any-evident Necta- ry. Sometimes the part under consideration is a pro- duction or elongation of the Corolla, as in Violets ; sometimes indeed of the Calyx, as in the Garden Nastur- tium, Tropaolum, Curt. Mag. t. 23 and 98, whose col- oured Calyx,/ 170, partakes much of the nature of the petals. Sometimes it is distinct from both, either re- sembling the petals, as in Aquilegia,f 171, Engl. Bot. t. 297, or more different, as in Epimedium,f. 172, 173, t. 438, Helleborus, t. 200 and 613, Aconitum, the Com- mon Monkshood, and Delphinium, the Larkspur. Such at least is the mode in which Linmeus and his followers understand the four last-mentioned flowers ; but wc have already hinted that Jussieu is of a different opinion, and he even calls the decided Nectary of Epimedium an internal petal ! Difficulties attend both theories. It seems paradoxical to call petals those singular bodies in Aconitum, f. 174, like a pair of little birds, which are manifestly formed only to hold the honey, and not situa- ted nor constructed so as to perform the proper functions of petals ; but on the other hand Ranunculus, t. 100, 515 and 516, one of the same natural order, has evident calyx and petals, which latter have a honey-bearing pore in their claw, evincing their identity with the less petal- like Nectaries just described. Other instances indeed 214 OP THE NECTAia of Nectaries in the claws of petals are found in the Crown Imperial and Lily ; which only confirms more strongly the compendious construction of the Lily tribe, the leaves of their flowers in these examples being Calyx, Petals and Nectaries all in one. The most indubitable of all Nectaries, as actually se- creting honey, are those of a glandular kind. In the natural order of Cruciform plants, composing the Lin- naean class Tetradynamia, these are generally four green gland*at the base of the Stamens. See Dentaria, Engl. Bot. t. 309, Sisymbrium, t. 525, and Brassica, t. 637. In Salix, t. 1488, and Geranium, t. 322, 75, &c, similar glands are observable ; whilst in Pelargonium, the Afri- can Geranium, the Nectary is a tube running down one side of the flower-stalk. The elegant Parnassia, t. 82, of which we are now acquainted with two new American species, has a most elaborate apparatus called by Linnaeus Nectaries,/ 175, but which the cautious Jussieu names Scales only. Lin- naeus usually called every supernumerary part of a flow- er Nectary, from analogy only, though he might not in ev- ery case be able to prove that such parts produced hon- ey. This is convenient enough for botanical distinc- tions, though perhaps not always right in physiology ; yet there is nothing for which he has been more severely and contemptuously censured. He was too wise to an- swer illiberal criticism, or he might have required his adversaries to prove that such parts were not Nectaries. Sometimes possibly he may seem to err, like L'Heritier, in calling abortive stamens by this name. Yet who knows that their filaments do not secrete honey as well AND HONEY. 21o as the tubes of numerous flowers ? And though abortive as to Antheras, the Filament, continuing strong and vig- orous, may do its office. Honey is not absolutely confined to the flower. The glands on the footstalks of Passion-flowers yield it, and it exudes from the flower-stalks of some liliaceous plants. The sweet viscid liquor in question has given rise to much diversity of opinion respecting its use. Pontede- ra thought it was absorbed by the seeds for their nour- ishment while forming, as the yolk of the egg iiy the chick. But Linnaeus observes in reply, that barren flowers produce it as well as fertile ones, witness Urtica and Salix. In some instances the fertile flowers only are observed to bear honey, as Phyllanthus and Tamus, but such cases are rare. Even Darwin says the honey is the food of the stamens and pistils, not recollecting that it is often lodged in spurs or cells quite out of their reach. There can be no doubt that the sole use of the honey with respect to the plant is to tempt insects, who in procuring it fertilize the flower, by disturbing the dust of the Stamens, and even carry that substance from the bar- ren to the fertile blossoms. 3. Stamina. The Stamens, formerly called Chives, are various in number in different flowers, from one to some hundreds. Their situation is internal with re- spect to the parts we have been describing ; external to the Pistils, at least in simple flowers. These organs are essential, there being no plant hitherto discovered, after the most careful research, 216 OF THE STAMENS that is destitute of them, eitjier in the same flower with the pistils, or a separate one of the same species. A Stamen,/ 176, commonly consists of two parts, the Filament, a, Filamentum, arid Anther, b*, Anthe- ra, the former being merely what supports the latter, which is the only essential part. Various forms and proportions of Filaments may be seen in the Tulip, where they are six in number, thick and short, Engl. Bot. t. 63 ; the Pink, where they are ten, much more slender, and answering to the idea of a filament or thread, t. 62 ; and Anemone, t. 51, where they are numerous. They are commonly smooth, but some- times, as in Verbascum, t. 58, 59, bearded. In Melal- euca, Exot. Bot. ti 36 and 50, they are branched ; and in Prunella, Engl. Bot. t. 961, forked, one point only bearing an Anther. In Aristolochia, t. 398, they are wanting, and nearly so in Potamogeton, t. 376, &c. (107) * I submit to the opinion of Professor Martyn in adopting this word, for the reasons given in his Language of Botany, more especially as general practice seems to favour its use. (107) [From the direction of their filaments, Stamens are said to be Conniventia,cotmivcnt, when they approach each other at their points. Incurva, incurved, when they are bent like a bow, as in Trichostema. Declinata, declined, when they tend towards the upper or un- der side of the flower, as in Rhododendron. Exserta, exserted, when they project out of the flower. Inculsa, included, when they are contained within the flower.] ! AND ANTHERS. 21/ The Anther is the only essential part of a Stamen. It is generally of a membranous texture, consisting of two cells or cavities, bursting longitudinally at their outer edges, as in the Tulip. In Erica, t. 1013—15, it opens by pores near the summit, as in the Potatoe- blossom. Very rarely the Anther has four cells, as Tetratheca, Bot. ofN. Holl. t. 5, and Exot. Bot. t* 20*—22. Sometimes it is ornamented with a crest, as in many Erica, and the genus Pinus. See Mr. Lambert's splendid work. The Pollen, or Dust, is Contained in the Anther, from which it is thrown out chiefly in warm dry weather, when the coat of the latter contracts and bursts. The Pollen, though to the naked eye a fine , powder, and light enough to be wafted along by the air, is so curiously formed, and so various in different plants, as to be an interesting and popular object for the microscope. Each grain of it is commonly a membranous bag, round or angular, rough or smooth, Which remains entire till it meets with any moisture, being contrary in this respect to the nature of the An- ther ; then it bursts with great force, discharging a most subtile vapour. In the Orchis family, and some other plants, the pollen is of a glutinous nature, very different from its usual aspect. See remarks on Mi- rabilis longiflora, Exot. Bot. v. 1. 44. The Stamens are changed to petals in double flow- ers, and rendered useless. They are often obliterated * In this plate the engraver has by mistake expressed the sec* tion of tue anther so as to look more like a germen, though tlw original drawing Was correct, DO US OF THE PISTILS. by excessive nourishment, or when the plant increas- es much by root, as in the Fiery Lily, or true Lilium bulbiferum. (108) 4. Pistilla. The Pistils, no less essential than the Stamens, stand within them in the centre of the flow- er, and are generally fewer. When in a different flower, on the same or a different plant, they are not always ceatral. Linnaeus conceived them to originate from the pith* and the stamens from the wood, and hence constructed an ingenious hypothesis, relative to the propagation of vegetables, which is not destitute of observations and analogies to support it, but not countenanced by the anatomy and physiology of the parts alluded to. Each Pistil,/ 177, consists of three parts. 1, the Germen, a, or rudiment of the young fruit and seed, which of course is essential ; 2, the Stylus, b, style, various in length and thickness, sometimes altogether wanting, and when present serving merely to elevate the third part, Stigma, c. This last is indispensable. Its shape is various, either simple, scarcely more than a point, or capitate, forming a little round head, or va- riously lobed. Sometimes hollow, and gaping more especially when the flower is in its highest perfection ; very generally downy, and always more or less moist with a peculiar viscid fluid, which in some plants is so copious as to form a large drop, though never big (108) [Stamens change to petals in the Pink, Daffodil, Tulip, Sec. They are obliterated by cultivation, in the Guelder Rose, Viburnum Ofiulus.] OF THE GERMEN. 219 enough to fall to the ground. The moisture is de- signed for the reception of the pollen, which explodes on meeting with it, and hence the seeds are rendered capable of ripening, which, though in many plants ful- ly formed, they would not otherwise be. The Germen appears under a variety of shapes and sizes. It is of great moment for botanical distinc- tions to observe whether it be superior, that is, above the bases of the calyx and corolla, as in the Strawber- ry and Raspberry, or inferior, below them, as in the Apple and Pear. Very rarely indeed the Germen is supposed to be betwixt the calyx and corolla, of which Sanguisorba, Engl. -Bot. t. 1312, is reckoned by Linnaeus an example ; but the corolla there has really a tube, closely embracing the Germen. In Adoxa, t. 453, the calyx is half-inferior, the corolla superior. When in botanical language we say ger- men superior, it is equivalent to flower inferior ; but it is sometimes more convenient and proper, for the sake of analogy or uniformity, to use one mode of ex- pression than the other. Pistils are sometimes obliterated, though oftener changed to petals, in double flowers, as well as the stamens ; but I have met with a much more remark- able change in the Double Cherry, of the pistil into a real leaf, exactly conformable to the proper leaves of the tree, only smaller. By this we may trace a sort of round in the vegetable constitution. Beginning at the herbage or leaves, we proceed insensibly to brac- teas in many species of Salvia, or to both calyx and corolla in the Garden Tulip, which frequently has a 229 THE SEED-VESSEL AND ITS KINDS. leaf half green half coloured, either in the flower or on the stalk just below it. Anemone alpina pioduces occa- sionallv a petal among the segments of its involucrum or bractea. Geum rivale, Engl. Bot. t. 106, when cultivated in dry gravelly ground, exhibits such trans- formations in abundance. Between petals and sta- mens there is evidently more connection, as to their nature and functions, than between any other organs, and they commonly flourish and fall together. Yet only one instance is known of petals changing to sta- mens, which Dr. Withering has commemorated, in the Black Currant, Ribes nigrum. On the other hand, nothing is more frequent than the alteration of stamens to petals. Here then the metamorphosis begins to be retrograde, and it is still more so in the Cherry above mentioned, by which we return to the herbage again. —The line of distinction seems to be most absolute between stamens and pistils, which never change into each other ; on the contrary, pistils, as we see, rather turn into petals, or even into leaves, 5, Pericarpium. The seed vessel, extremely various in different plants, is formed of the germen enlarged. It is not an essential part, the seeds being frequently naked, and guarded only by the calyx, as in the first order of the Linnaean class Didynamia, of which La- mium Engl. Bot. t. 768, and Galeopsis, t. 667, are examples ; also in the great class of compound flow- ers Syngenesia, as well as in Rumex, t. 724, Polygo- num, t. 989, the Umbelliferous tribe, numerous Grasses, &c. THE CAPSULE AND ITS KINDS. 221 The use of the Seed-vessel is to protect the seeds till ripe, and then in some way or other to promote their dispersion, either scattering them by its elastic power, or serving for the food of animals in whose dung the seeds vegetate, or promoting the same end by various other means. The same organ which re- mains closed so long as it is juicy or moist, splits and flies asunder when dry, thus scattering the seeds in weather most favourable for their success. By an extraordinary provision of Nature, however, in some annual species of Mesembryanthemum, f 178, na- tives of sandy deserts in Africa, the seed-vessel opens only in rainy weather ; otherwise the seeds might, in that country, lie long exposed before they met with sufficient moisture to vegetate. 1. Capsula, a Capsule, is a dry seed-vessel of a woody, coriaceous or membranous texture, generally split- ting into several valves ; more rarely discharging its contents by orifices or pores, as in Campanula and Pa- paver ; or falling off entire with the seed. Internally it consists either of one cell or several ; in the latter case the parts which separate the cells are called dis- sepimenta, partitions. The central column to which the seeds are usually attached is named columella. See Datura Stramonium, f 179, Engl. Bot. t. 1288. Gartner, a writer of primary authority onfruilfcand seeds, reckons several peculiar kinds of Capsules, be- sides what are generally understood as such ; these are Utriculus, a Little Bladder, which varies in thick- ness, never opens by any valves, and falls off with the -222 THE CAPSULE AND ITS KINDS seed. I believe it never contains more than one seed, of which it is most commodiously, in botanical lan- guage, called an external coat, rather than a Capsule. Gaertner applies it to Chenopodium, as well as to Cle- matis, &c. In the former it seems a Pellicula, in the latter a Testa, as we shall hereafter explain. Samara is indeed a species of Capsule, of a com- pressed form and dry coriaceous texture, with one or two cells, never bursting, but falling off entire, and dilated into a kind of wing at the summit or sides. It is seen in the Elm, the Maple, the Ash, Engl. Bot. t. 1692, and some other plants. This term however may well be dispensed with, especially as it is the name of a genus in Linnaeus ; an objection to which Cotyledon too is liable. Folliculus, a Follicle or Bag, reckoned by Linnaeus a separate kind of seed-vessel from the Capsule, ought perhaps rather to be esteemed a form of the latter, as Gaertner reckons it. This is of one valve and one cell, bursting lengthwise, and bearing the seeds on or near its edges, or on a receptacle parallel therewith. Instances are found in Vinca, t. 514, Paonia, t. 1513, and Embothrium, Bot. of New Holland, (109) t. 7— 10. Coccum of Gaertner, separated by him from cap- sules, is a dry seed-vessel, more or less aggregate, not solitary, whose sides are elastic, projecting the seeds with great force, as in Euphorbia ; also Boronia, Tracts on Nat. Histpry, t. 4—7. This seems by no (108) [The seeds of dsclefiias and Aftocynum are contained i- Follicles."! / THE SILIQUA AND LEGUMEN. ^223 means necessary to be esteemed otherwise than a sort of capsule. 2. Siliqua,f. 180, a Pod, is a long dry solitary seed-ves- sel of two valves, separated by a linear receptacle, along each of whose edges the seeds are ranged alter- nately, as in the class Tetradynamia. See Cherian- thus, Engl. Bot. t. 462, and Cardamine, t. 80 ; also Bignonia echinata, figured by Gaertner, t. 52, / 1, which, though cautiously called by him a capsula sili- quosa only, is as true a Silqua, according to his own definition, and every body's ideas, as possible ; so is also that of Chelidonium. He justly indeed names the fruit of Paonia capsula leguminosa, a follicle with him being a single-valved capsule, with the seeds marginal as in a legume. Silicula,f. 181, a Pouch, is only a Pod of a short or rounded figure, like Draba verna, Engl. Bot. t. 586. (110) 3. Legumen,f 182, a Legume, is the peculiar solitary fruit of the Pea kind, formed of two oblong valves, without any logitudinal partition, and bearing the seeds along one of its margins only. See Engl. Bot. t. 1046, 805, &c. The Tamarind is a Legume filled with pulp, in which the seeds are lodged. The Cap- sules of Helleborus and some other plants allied there- to, justly indicated by Gaertner as approaching very nearly to the definition of Legumes, differ essentially (110) [The Radish and Mustard are familiar examples of the Siliqua, the Thlasfti, or Shepherd's Purse, of the Silicula.~\ 224 THE LEGUMEN AND DRUPA. in not being solitary, and in consisting each but of one valve. Some Larkspurs indeed bear such capsules solitary, but analogy teaches us their true nature. When a Legume is divided into,several cells, it is either by transverse constrictions, or by inflexion of the valves ; never by a separate longitudinal partition ; see Dolichos purpureus, Exot. Bot. t. 74. (111) Sometimes this kind of fruit lodges bin one seed, as in many species of Trifohum ; see Engl. Bot. t. 1048, also Viminaria denudata, Exot. Bot. t. 27. It is only by analogy that such are known to be Le- gumes. 4. Drupa, f. 183, a Stone-fruit, has a fleshy coat, not separating into valves, containing a single hard and bony Nut, to which it is closely attached ; as in the Peach, Plum, Cherry, &c. ; see Engl. Bot. t. 706 and 1383. The Cocoa-nut is a Drupa with a less juicy coat. Sometimes the Nut, though not separating into distinct valves, contains more than one cell, and conse- quently several seeds. Instances are found in Cor- nus, t. 249, Gartner, t. 26, and Olea, the Olive, Fl. Grac. t. 3, though one cell of the latter is commonly abortive. (Ill) [The term Lomentum orLoment expresses an elongated principle consisting of two valves, externally forming sutures, but never bursting like the legume. Internally it is divided in- to cells by small transverse partitions. It occurs in Cassia, He- -iysarum, &c] THE POMUM AND BACCA. 225 5. Pomum,f. 184, an Apple, has a fleshy coat like the Drupa, but containing a Capsule with several seeds ; as iii common Apples and Pears ; see Pyrus domesti- ca, t. 350. This is comprehended by Gaertner under the dif- ferent kinds of Bacca, it being sometimes scarcely possible to draw the line between them ; witness the Linnean genus Sorbus. 6. Bacca, f 185, a Berry, is fleshy, without valves, con- taining one or more Seeds, enveloped with pulp. It becomes more juicy internally as it advances to matu- rity, quite contrary to the nature of a Capsule, though the difference between these two unripe fruits may not be discernible, and though some true Berries, when fully ripe, finally become of a dry and spongy- texture ; but they never open by valves or any regu- lar orifice. Examples of a Bacca are seen in Atropa Belladonna, Engl. Bot. t. 592, and Ribes, t. 1289— 92. The same part in Hedera, t. 1267, is of a more mealy substance. In Cucubalus, t. 1577, the coat on- ly is pulpy. In Trientalis, t. 15, the coat becomes very dry and brittle, as soon as ripe, and the cavity of the fruit is nearly filled by a globular columella. See Gaertner, t. 50. Bacca composita,f. 186, a Compound Berry, con- sists of several single ones, each containing a seed, united together, as in Rubus, the Raspberry, Bramble, &c, Engl. Bot. t. 715, 716, 826, 827. Each of the separate parts is denominated an Acinus, or Grain, EE 226 SPURIOUS KINDS OF BACC.3E. which term Gaertner extends to the simple many- seeded berries of the Vine, Gooseberry, &cc. The Orange and Lemon are true Berries, with a thick coat. The Melon and Cucumber tribe have a peculiar sort of Berry for which Gaertner uses the name of Pepo, Gourd ; and he defines it a Berry whose cells, together with the seeds, are remote from the axis or centre, the seeds being inserted into the sides of the fruit. Passifiora, suberosa,f. 187, Exot. Bot. t. 28, shows this insertion, being nearly allied to the same tribe ; but in this genus the pulp invests each seed separately, forming Acini within the com- mon cavity. Some fruits ranged by Linnaeus as Drupa with many seeds, on account of the hardness of the shells of those seeds, are best perhaps, on account of their number, considered by Gaertner as Bacca. Among these are Mespilus, the Medlar. There are several spurious kinds of berries, whose pulp is not properly a part of the fruit, but originates from some other organ. Thus, in the Mulberry, as well as the Strawberry Spinach, Blitum, Curt. Mag. t. 276, the Calyx after flowering becomes coloured and very juicy, investing the seed, like a genuine ber- ry. The Corolla of Commelina Zannonia undergoes a similar change, forming a black very juicy coat to the capsule, being totally altered both in shape and substance from its appearance in the flower. In the Juniper, Engl. Bot, t. 1100, a few scales of the fertile catkin become succulent and coalesce into a globular SPURIOUS KINDS OF BACC.K. 227 berry with three or more seeds, to which Gaertner ap- plies the term galbulus, the classical name of the Cypress fruit, which last however is as true a strobilus or cone as that of the Fir. In the Yew, t. 746, some have thought it a calyx, others a peculiar kind of re- ceptacle, which becomes red and pulpy, embracing the seed. Lamarck has in his Encyclopedic, v. 3, 228, considered this fruit as a real bacca or drupa, with the idea or definition of either of which it cannot by any means be made to accord, being open at the top, and having no connection with the stigma, which crowns the seed itself. The same writer mistakes for a calyx the scales which analogy shows to be bracte- as ; and I cannot think Jussieu and Gaertner more correct in their ideas of this singular fruit, when they call the pulpy part in question a receptacle, though the term calyx seems less paradoxical, and is perhaps still more just.* We do not know enough of Taxus nucfera to draw any conclusions from thence. See Gartner, t. 91. In the Strawberry, Engl. Bot. t. 1524, what is commonly called the berry is a pulpy receptable, studded with naked seeds, In the Fig, Gartner, t. 91, the whole fruit is a juicy calyx, or rather common receptacle, containing in its cavity in- numerable florets, each of which has a proper calyx of its own, that becomes pulpy and invests the seed, as in its near relation the Mulberry. The Paper * Hernandia, G THE RECEPTACLE the Calyx, beset with hooks, forms the bur, as in Arctium,,Lappa, Engl. Bot. t. 1228 ; sometimes hooks encompass the fruit itself, as in Xanthi- um, and some species of Galium, particularly G. Aparine, t. 816. Plants thus furnished are observed by Linnaeus to thrive best in a rank manured soil, with which, by being conveyed to the dens of wild animals, they are most likely to meet. The Awns of grasses answer the same end. Pulpy fruits serve quadrupeds and birds as food, while their seeds, of- ten small, hard, and indigestible, pass uninjured through the intestines, and are deposited far from their original place of growth, in a condition peculiar- ly fit for vegetation. Even such seeds as are them- selves eaten, like the various sorts of nuts, are hoarded up in the ground and occasionally forgotten, or carried to a distance, and in part only devoured. Even the ocean itself serves to waft the larger kinds from their native soil to far-distant shores. 7. Receptaculum. The Receptacle is the common base or point of connexion of the other parts of fruc- tification. It is not always distinguishable by any par- ticular figure, except in compound flowers constitu- ting the Linnaean class Syngenesia, in which it is very remarkable and important. In the Daisy,/ 208, Engl. Bot. t. 424, it is conical ; in Chrysanthe- mum, t. 601, convex ; in others flat, or slightly con- cave. Picris, t. 972, has it naked, that is destitute of any hairs or scales between the florets or seeds ; Car- duus, t. 675, hairy ; Anthemis, t. 602, scaly ; and VARIOUS KINDS OF FLOWERS. 241 Onopordum, t. 977, cellular like a honey-comb, / 209. On this and the seed-down are founded the most solid generic characters of these plants, admira* bly illustrated by the inimitable Gaertner. The term Receptacle is sometimes extended by Linnaeus to express the base of a flower, or even its internal part between the stamens and pistils, provid- ed there be any thing remarkable in such parts, with- out reference to the foundation of the whole fructifi- cation. It also expresses the part to which the seeds are attached in a seed-vessel. Having thus explained the various organs of fructifi- cation, we shall add a few remarks concerning flowers in general, reserving the functions of the Stamens and Pis- tils, with the Linnaean experiments and inquiries relative to that curious subject, for the next chapter. A flower furnished with both calyx and corolla is cal- led fios completus, a complete flower ; when the latter is wanting, incompletus ; and when the corolla is present without the calyx, nudus, naked. When the stamens and pistils are both, as usual, in one flower, that flower is called perfect, or united ; when they are situated in different flowers of the same species, such I would call separated flowers ; that which has the stamens being named the barren flower, as producing no fruit in itself, and that with pistils the fertile one, as bearing the seed. If this separation extends no further than to different sit- uations on the same individual plant, Linnseus calls GG U2 COMPOUND FLOWERS. such flowers monoid, monoecious, as confined to one house or dwelling ; if the barren and fertile flowers grow from two separate roots, they are said to be dioici, dioecious. Some plants have united flowers and separa- ted ones in the same species, either from one, two or three roots, and such are called polygamous, as making a sort of compound household. A Compound flower consists of numerous florets,/os- culi, all sessile on a common undivided Receptacle, and enclosed in one contiguous Calyx or Perianthium. It is also essential to this kind of flower that the Anthers should be united into a cylinder, to which only the genus Tus- silago affords one or two exceptions, and Kuhnia anoth- er ; and moreover, that the stamens should be 5 to each floret, Sigesbeckia fiosculosa of L'Heritier, Stirp. Nov. t. 19, alone having but 3. The florets are always mo- nopetalous and superior, each standing on a solitary na- ked seed, or at least the rudiments of one, though not al- ways perfected. Some Compound flowers consist of very few florets, as Humea elegans, Exot. Bot. t. 1, Prenanthes muralis, Engl. Bot. t. 457 ; others of many, as the Thistle, Daisy, Sunflower, &c. The florets them- selves arc of two kinds, ligulati, ligulate, shaped like a strap or ribband,/ 210, with 3 or 5 teeth, as in Trago- pogon, t. 434, and the Dandelion ; or tubulosi, tubular, cylindrical and 5-cleft, as in Carduus, t. 107, and Tana- cetum, t. 1229. The marginal white florets of the Daisy,/ 211, are of the former description, and com- pose its radius, or rays, and its yellow central ones come under the latter denomination,/ 212, constituting its discus, or disk. The disk of such flowers is most fre- AGGREGATE FLOWERS. 243 quently yellow, the rays yellow, white, red, or blue. No instance is known of yellow rays with a white, red, or blue disk. An Aggregate flower has a common undivided Recep- tacle, the Anthers all separate and distant, Jasione only, Engl. Bot. t. 882, having them united at the base, but not into a cylinder, and the florets commonly stand on stalks, each having a single or double partial calyx. Such flowers have rarely any inclination to yellow, but are blue, purple, or white. Instances are found in Sea- biosa, t. 659, and 1311, Dipsacus, t. 1032 and 877, and the beautiful Cape genus Protea. Such is the true idea of an Aggregate flower, but Lin- naeus enumerates, under that denomination, 7 kinds, his favourite number ; these are, 1. The Aggregate flower properly so called, as just mentioned. 2. The Compound flower previously described. 3. The Amentaceous flower, or Catkin, of which we have spoken, p. 200. 4. The Glumose, or Chaffy flower, peculiar to the Grasses, see p. 201. 5. The Sheathed flower, whose common receptacle springs from a Sheath, as in Arum. 6. The Umbellate ; and 7. The Cymose flowers, concerning which two last a few observations are necessary. Linnaeus and his friend Artedi thought the great nat- ural umbelliferous order could not be divided into good 244 AGGREGATE AND and distinct genera by the seeds or parts of the flower, without taking into consideration the general and partial involucral leaves, which they therefore chose to consider as a part of the fructification, and defined as a calyx re- mote from the fiower. The rays of the umbel, of course, became the subdivisions of a branched recepta- cle, and the whole umbel was considered as one aggre- gate flower. It necessarily followed that a Cyme, see p. 192, must be considered in the same light, nor did the sagacity of Linnaeus overlook the arguments in fa- vour of this hypothesis. Many of the umbelliferous tribe, as Heracleum, t. 939, Caucalis, Coriandrum, &c, have their marginal flowers dilated, radiant, and more or less inclined to be imperfect or abortive, thus evincing an analogy with real compound flowers like the Sunflow- er, which analogy is still more striking between Oe- nanthe, t. 363, 347, 348, and the Marigold, Calendula. So the cymose plants, as Viburnum Opulus, t. 332, bear dilated and abortive marginal flowers, and Hydrangea hortensis, Sm. Ic. Pict. t. 12, has scarcely any others. Cornus sanguinea, Eng[. Bot. t. 249, has a naked cyme, Suecica, t. 310, an umbel accompanied by coloured bracteas, or, as Linnaeus judged, a coloured involucrum, proving the close affinity between these two modes of inflorescence. Notwithstanding all this, I presume to dissent from the above hypothesis, as offering too great violence to Nature, and swerving from that beautiful and philosoph- cal Linnaean principle, of characterizing genera by the fructification alone ; a principle which those who are competent to the subject at all, will, I believe, never COMPOUND FLOWERS. 245 find to fail. The seeds^and flowers of the umbelliferous family are quite sufficient for our purpose, while the in- volucrum is very precarious and changeable ; often de- ficient, often immoderately luxuriant, in the same genus. In the cymose plants every body knows the real parts of fructification to be abundantly adequate, the involucrum being of small moment; witness that most natural genus Cornus. For all these, and other reasons, to particular- ize which would lead me too far, I have, p. 191, rec- koned the Umbel and Cyme modes of flowering, and not themselves aggregate flowers. [ 2*6 ] CHAPTER XX. OF THE PECULIAR FUNCTIONS OF THE STAMENS AND PIS- TILS, WITH THE EXPERIMENTS AND OBSERVATIONS OF LINNJGUS AND OTHERS ON THAT SUBJECT. The real use of the Stamens of Plants was long a subject of dispute among philosophers, till Linnaeus, ac- cording to the general opinion at present, explained it beyond a possibility of doubt. Still there are not want- ing persons who from time to time start objections, prompted either by a philosophical pursuit of truth, or an ambitious desire of distinguishing themselves in con- troverting so celebrated a doctrine, as some have writ- ten against the circulation of the animal blood. I pro- pose to trace the history of this doctrine, and especially to review the facts and experiments upon which Linnaeus founded his opinion, as well as the objections it has had to encounter. It would be endless, and altogether su- perfluous, to bring forward new facts in its support, nor shall I do so, except where new arguments may render such a measure necessary. The Stamens and Pistils of flowers have, from the most remote antiquity, been considered as of great im- portance in perfecting the fruit. The Date Palm, from time immemorial a primary object of cultivation in the more temperate climates of the globe, bears barren and fertile flowers on separate trees. The ancient Greeks soon discovered that in order to have abundant and well-flavoured fruit, it was expedient to plant both FUNCTIONS OF STAMENS AND PISTILS. 347 trees near together, or to bring the barren blossoms to those which were to bear fruit; and in this chiefly con- sisted the culture of that valuable plant. Tournefort tells us that without such assistance dates have no ker- nel, and are not good food. The same has long been practised, and is continued to this very day in the Le- vant, upon the Pistacia, and the Fig. At the revival of learning botanists were more occupied in determining the species, and investigating the medi- cal properties of plants, than in studying their physiolo- gy ; and when after a while the subject in question was started, some of them, as Morison, Tournefort and Pontedera, uniformly treated with great contempt the hypothesis which has since been established. We shall, as we proceed, advert to some of their arguments. About the year 1676, Sir Thomas Millington, SaviU ian Professor at Oxford, is recorded to have hinted to Dr. Grew that the use of the Stamens was probably to perfect and fertilize the seed. Grew adopted the idea, and the great Ray approved it. Several other botanists either followed them, or had previously conceived the same opinion, among which R. J. Canerarius, Professor at Tubingen towards the end of the seventeenth centu- ry, was one of the most able and original. Vaillant wrote an excellent oration on the subject, which being hostile to the opinions of Tournefort, lay in obscurity till published by Boerhave. Blair and Bradley assented in England, and several continental botanists imbibed the same sentiments. Pontedera, however, at Padua, an university long famous, but then on the decline, and consequently adverse to all new inquiry and information, 248 FUNCTIONS OF in 1720 published his Anthologia, quite on the other side of the question. Linnaeus, towards the year 1732, reviewed all that had been done before him, and clearly established the fact so long in dispute, in his Fundamenta and Philosophia Botanica. He determined the functions of the Stamens and Pistils, proved these organs to be essential to every plant, and thence conceived the happy idea of using them for the purpose of systematical arrangement. In the latter point his merit was altogether original ; in the former he made use of the discoveries and remarks of others, but set them in so new and clear a light, as in a manner to render them his own. We have already mentioned, p. 121, the two modes by which plants are multiplied, and have shown the im- portant difference between them. Propagation by seed is the only genuine reproduction of the species, and it now remains to prove that the essential organs of the flower are indispensably requisite for the perfecting of the seed. Every one must have observed that the flower of a plant always precedes its fruit. To this the Meadow Saffron, Engl. Bot. t. 133, seems an objection, the fruit and leaves being perfected in the spring, the blossoms not appearing till autumn ; but a due examination will readily ascertain that the seed-bud formed in autumn is the very same which comes to maturity in the following spring. A Pine-apple was once very unexpectedly ci- ted to me as an instance of fruit being formed before the flower, because the green fruit in that instance, as in many others, is almost fully grown before the flowers ex- STAMENS AND PISTILS, 2*9 pand. The seeds however, the essence of the fruit, are only in embryo at this period, just as in the germen of an Apple blossom. It was very soon ascertained that flowers are invaria- bly furnished with Stamens and Pistils, either in the same individual, or two of the same species, however defective they may be in other parts ; of which Hippu- ris, Engl. Bot. t. 763, the most simple of all blossoms, is a remarkable example. Few botanists indeed had detected them in the Lemma or Duck-weed, so abun- dant on the surface of still waters, and Valisneri alone for a long time engrossed the honour of having seen them. In our days however they rewarded the researches -of the indefatigable Ehrhart in Germany, and on being; sought with equal acuteness, were found in England^ Three species have been delineated in Engl. Bot. t- 926, 1095, and 1233, from the discoveries of Mr. Tur- ner and Mr. W. Borrer. The flowers of Mosses, long neglected and afterwards mistaken, were faithfully de- lineated by Micheli, carefully examined and properly understood by Linnaeus as he rambled over the wilds o£ Lapland*, and at length fully illustrated and placed ouc of all uncertainty by the justly celebrated Hedwig, These parts indeed are still unknown in ferns, or at least no satisfactory explanation of them has reached me, though the seeds and seed-vessels are sufficiently obvi- ous. The existence of the parts under consideration is so incontrovertible in every flower around us, that Ponte- * This hitherto unknown fact will appear in his Tour through that country, now preparing tor the press in English. HH ■J 50 FUNCTIONS OF dera was reduced to seek plants without stamens among the figures of the Hort us Malabaricus, but the plates in which he confided are now known to be faulty in that very particular. Plants indeed have occasionally abortive stamens in one flower and barren pistils in another, and the Plan- tain-tree, Musa, is described by Linnaeus as having five out of its six stamens perfected in such blossoms as ri- pen no fruit, while those with a fertile germen contain only a single ripe stamen, five being ineffective. This only shows the resources, the wisdom, and the infinite variety of the creation. When the roots are luxuriantly prolific, the flowers are in some measure defective, Na- ture, relaxing as it were from her usual solicitude, and allowing her children to repose, and indulge in the abund- ance of good things about them. But when want threatens, she instantly takes the alarm ; all her energies are exerted to secure the future progeny, even at the hazard of the parent stock, and to send them abroad to colonise more favourable situations. Most generally the access of the pollen is not trusted to any accidental modes of conveyance, however nume- rous, elaborate, and, if we may so express it, ingenious, such modes may be ; but the Stamens are for greater security lodged in the same flower, under the protection of the same silken veils, or more substantial guards, which shelter their appropriate pistils. This is the case with the majority of our herbs and shrubs, and even with the trees of hot countries, whose leaves being al- ways present might impede the passage of the pollen. On the contrary, the trees of cold climates have general STAMENS AND PISTILS. 251 ly separated flowers, blossoming before the leaves come forth, and in a windy season of the year ; while those which blossom later, as the Oak, are either peculiarly frequented by insects, or, like the numerous kinds of Fir, have leaves so little in the way, and pollen so exces- sively abundant, that impregnation can scarcely fail. The pollen and the stigma are always in perfection at the same time, the latter commonly withering and falling off a little after the anthers, though the style may remain to become an useful appendage to the fruit. The Viola tricolor or Pansy, the Gratiola, the Martynia, and many plants besides, have been observed to be furnished with a stigma gaping only at the time the pollen is ripe. The beautiful Jacobean Lily, Amaryllis formossissima, Curt. Mag. t. 47, is justly described by Linnaeus as provided with a drop of clear liquid, which protrudes every morn- ing from the stigma, and about noon seems almost ready to fall to the ground. It is however re-absorbed in the afternoon, having received the pollen whose vapour renders it turbid, and whose minute husks afterwards remain upon the stigma. The same phoenomenon takes place several successive days. In opposition to similar facts, proving the synchro- nous operation of these organs, Pontedera has, with more observation than usual, remarked that in the um- belliferous tribe the style frequently does not appear till the anthers are fallen. But he ought to have perceived that the stigma is previously perfected, and that the style seems to grow out afterwards, in a recurved and divari- cated form, for the purpose of providing hooks to the -eeds. It is also observable that in this family the sev ^5.2 FUNCTION'S «1 eral organs are sometimes brought to perfection in differ- ent flowers at different times, so that the anthers of one may impregnate the stigmas bf another, whose stamens were abortive, or long since withered. The same thing happens in other instances. Linnaeus mentions the Ja- tropha urens as producing flowers with stamens some weeks in general before or after the others. Hence he obtained no seed till he preserved the pollen a month or more in paper, and scattered it on a few stigmas then in perfection. There can be no doubt that, in a wild stale, some or other of the two kinds of blossoms are ripe to- gether, throughout the flowering season, on different trees. A similar experiment to that just mentioned was made in 1749 upon a Palm-tree at Berlin, which for want of pollen had never brought any fruit to perfection. A branch of barren flowers was sent by the post from Leip- sic, twenty German miles distant, and suspended over the pistils. Consequently abundance of fruit was ripened, and many young plants raised from the seeds.* * What species of Palm was the subject of this experiment does not clearly appear. In the original communication to Dr. Watson, printed in the preface of Lee's Introduction to Botany, it is called Palma major foliis flab ellif or mibus, which seems ap- propriate to Rafthis flab ellifirmis, Ait. Hort. Keiv. v. 3. 473 ; yet Linnaeus, in his dissertation on this subject, expressly calls it Phcenix dactylifera, the Date Palm, and says he had in his gar- den many vigorous plants raised from a portion of the seeds above mentioned. The great success, of the experiment, and the " fan shaped" leaves, makes mc rather take it for the R/ia- fiis,a, plant not well known to Linnaeus. STAMENS AND PISTILS. 2&v Tournefort and Pontedera supposed the pollen to be of an excrementitious nature, and thrown off as superflu- ous. But its being so curiously and distinctly organiz- ed in every plant, and producing a peculiar vapour on the accession of moisture, shows, beyond contradiction, that it has functions to perform after it has left the anther. The same writers conceived that the stamens might possibly secrete something to circulate from them to the young seeds ; an hypothesis totally subverted by every flower with separated organs, whose stamens could circu- late nothing to germens on a different branch or root ; a difficulty which the judicious Tournefort perceived^ and was candid enough to allow. Both the conjectures just mentioned vanish before one luminous experiment of Linnaeus, of all others the most easy to repeat and to understand. He removed the anthers from a flower of Glaucium phozniceum ; Engl. Bot. t. 1433, stripping off the rest of that day's blossoms. Another morning he repeated the same prac- tice, only sprinkling the stigma of that blossom, which he had last deprived of its own stamens, with the pollen from another. The flower first mutilated produced no fruit, but the second afforded very perfect seed. " My design," says Linnaeus, " was to prevent any one in fu- ture from believing that the removal of the anthers from a flower was in itself capable of rendering the germen abortive." The usual proportion and situation of stamens with respect to pistils is well worthy of notice. The former are generally shortest in drooping flowers, longest in 254 FUNCTION S OF S1 AMENS AND PISTILS. erect ones. The barren blossoms stand above the fertile ones in Carex, Coix, Arum, &c, that the pollen may fall on the stigmas. This is the more re- markable, as the usual order of Nature seems in such plants, as well indeed as in compound, and even um- belliferous flowers, to be reversed, for the pistils are invariably central, or internal, in every simple flower> and would therefore, if drawn out into a monoecious spike, be above the stamens. Many curious contrivances of Nature serve to bring the anthers and stigmas together. In Gloriosa, Andr. Repos. t. 129, the style is bent, at a right angle from the very base, for this evident purpose. In Saxifraga, and Parnassia, Engl. Bot. t. 82, the stamens lean one or two at a time over the stigma, retiring after they have shed their pollen, and giving place to others ; which wonderful oeconomy is very striking in the garden Rue, Rutagraveolens, whose stout and firm filaments cannot be disturbed from the posture in which they may happen to be, and evince a spontaneous movement unaffected by external causes. The five filaments of the Celosia, Cock's-comb, are connected at their lower part by a membranous web, which in moist weather is relaxed, and the stamens spread for shelter under the concave lobes of the corolla. When the air is dry, the contrac- tion of the membrane brings them together, to scatter their pollen in the centre of the flower. The elastic fila- ments of Parietaria, Engl. Bot. t. 879, for a while re IRRITABLE FARTS OF FLOWERS- 255 strained by the calyx, as those of the lovely Kalmia,(\\6) Curt. Mag. t. 175, 177, are by the minute pouches in the corolla, relieve themselves by an elastic spring, which in both instances serves to dash the pollen with great force upon the stigma. The same end is accomplished by the curved germen of Medicagofalcata, Engl. Bot. t> 1016, releasing itself by a spring from the closed keel of the flower. But of all flowers that of the Barberry-bush, t. 49, is most worthy the attention of a curious physiologist. In this the six stamens, spreading moderately, are sheltered under the concave tips of the petals, till some extraneous body, as the feet or trunk of an insect in search of honey, touches the inner part of each filament near the bottom. The irritability of that part is such, that the filament im- mediately contracts there, and consequently strikes its anther, full of pollen, against the stigma. Any other part of the filament may be touched without this effect, provided no concussion be given to the whole. After a while the filament retires gradually, and may again be stimulated ; and when each petal, with its annexed fila- ment, is fallen to the ground, the latter on being touched shows as much sensibility as ever. See Tracts on Nat. History, 165. I have never detected any sympathy be- tween the filaments, nor is any thing of the kind expres- sed in the paper just mentioned, though Dr. Darwin, from some unaccountable misapprehension, has quoted (11 fi) [The ten stamens of the Kalmias are bent outward, and their anthers confined in the same number of depressions in the corolla, until liberated in the manner described.] 5>56 OF THE BARBERRY. me to that effect. It is still more wonderful that the celebrated Bonnet, as mentioned in Senebier's Physiolo- gic Vegetale, v. 5. 105, should have observed this phoe- nomenon in the Barberry so very inaccurately as to com- pare it to the relaxation of a spring, and that the ingen- ious Senebier himself, in quoting me, p. 94, for having ascertained the lower part only of each filament to be ir- ritable, should express himself as follows :—" It has not yet been proved that the movement of the stamens is at- tended with the contraction of the filaments ; which nevertheless* was the first proof necessary to have been given in order to ascertain their irritability ; it is not even yet well known which is the irritable part of the filaments, and whether it be only their base, as Smith has had the address to discover." In answer to which I need only request any one to read the above account, or the more ample detail in my original paper, and, above all, to examine a Barberry-blossom for himself; and if any doubts remain concerning the existence of vegetable irritability, let him read Senebier's whole chapter intend- ed to disprove it, where that candid philosopher, while he expresses his own doubts, has brought together every thing in its favour. Among the whole of his facts noth- ing is more decisive than the remarks of Coulomb and Van Mammon the Euphorbia, whose milky juices flow* so copiously from a wound, in consequence of the evi- dent irritability of their vessels ; but when the life of the'plant is destroyed by electricity, all the flowing is at an end. It is superfluous to add any thing on this sub- ject, and I return to that of the impregnation of flowers. PROTECTION OF THE POLLEN. 257 I have already mentioned that any moisture causes the pollen to explode, consequently its purpose is liable to be frustrated by rain or heavy dews. Linnaeus observes that husbandmen find their crops of rye to suffer more from this cause than barley, because in the latter the an- thers are more protected by the husks ; and the* Juni- per berries are sparingly, or not at all, produced in Swe- den when the flowering season has been wet. The same great observer also remarks, what yearly experi- ence confirms, that Cherry-trees are more certainly fruit- ful than Pear-trees, because in the former the opening of the anthers is, in each blossoirj, much more progres- sive, so that a longer period elapses for the accomplish- ment of the fertilization of the germen, and there is con- sequently less chance of its being hindered by a few showers. To guard against the hurtful influence of nocturnal dews or drenching rains, most flowers either fold their petals together, or hang down their heads, when the sun does not shine ; by which, their internal organs are sheltered. In some which always droop, as the Snow- drops Galanthus and Leucojum, Engl. Bot. t. 19 and 621, the Fritillary, t. 622, the Crown Imperial, various species of Campanula, and others, while the over-shad- owing corolla keeps off rain, the air has free access un- derneath to blow the pollen to the stigma. Nor is this drooping caused by the weight of the flowers, for the fruit in most of them is much heavier, and yet stands erect on the very same stalk. The papilionaceous flow- ers in general spread their wings in fine weather, admit- n 258 EXPERIMENTS ON HEMP ting the sun and air to the parts within ; whereas many of them not only close their petals at night, but also de- rive additional protection from the green leaves of the plant folding closely about them. Convolvulus arven- sis, t. 312, Anagallis arvensis, t. 529, Calendula pluvi- alis, and many others, are well known to shut up their flowers against the approach of rain ; whence the Anagallis has been called the Poor Man's Weather- glass. It has been observed by Linnaeus that flowers lose this fine sensibility, either after the anthers have performed their office, or when deprived of them arti- ficially ; nor do I doubt the fact. I have had reason to think that, during a,long continuance of wet, the sen- sibility of the Anagallis is sometimes exhausted ; and it is evident that very sudden thunder-showers often take such flowers by surprise, the previous state of the atmos- phere not having been such as to give them due warning. That parts of vegetables not only lose their irritabili- ty, but even their vital principle, in consequence of hav- ing accomplished the ends of their being, appears from an experiment of Linnaeus upon Hemp. This is a dioe- cious plant, seej&. 241, and Linnaeus kept several fer- tile-flowered individuals in separate apartments from the barren - ones, in order to try whether they could perfect their seeds without the aid of pollen. Some few how- ever remained with the barren-flowered plants, and these ripened seed in due time, their stigmas having faded and withered soon after they had received the pollen. On the contrary, the stigmas which had been out of its reach continued green and vigorous, as if in vain expec- tation, nor did they begin to fade till they had thus last- MELONS, CYCAS, &c. 259 ed for a very long while. Since I read the history of this experiment, I have found it easy in many plants to tell by the appearance of the stigma whether the seed be fertilized or not. The above experiment is the more important, as the abbe Spallanzani has recorded one made by himself upon the same species of plant, with a contrary result. But as he has said nothing of the ap- pearance of the stigmas, his experiment must yield to that of Linnaeus in point of accuracy ; and even if his account be otherwise correct, the result is easily ex- plained. Hemp, Spinach, some Nettles, &c, naturally dioecious, are occasionally not completely so, a few latent barren or fertile flowers being frequently found among those of the other sort, by which provision is made against accidents, and the perfecting of a few seeds, at any rate, secured. In general, germens whose stigmas have not received the pollen wither away without swelling at all, but some grow to a considerable size, and in such the substance of the seed, its skin, and even its cotyledons, are often to be found, the embryo only being wanting. In a Melon or Cucumber it is common to find, among numerous perfect seeds, many mere unimpregnated husks. In the magnificent Cycas revoluta, which bore fruit at the bishop of Winchester's, and of which a history with plates is given in the sixth volume of the Linnaean So- ciety's Transactions, I found the drupa and all its con- tents apparently perfect, except that there was only a minute cavity where the embryo should have been, in consequence of the want of another tree with stamens, which was not to be found perhaps nearer than Japan 260 OZCONOMY OF AQUATIC PLANTS. Gardeners formerly attempted to assist Nature by strip- ping, off the barren flowers of Melons and Cucumbers, which, having no germen, they found could not come to fruit, and were, therefore, as they .supposed, an unneces- sary encumbrance to the constitution of the parent plant. But finding they thus obtained no fruit at all, they soon learned the wiser practice of admitting air as often as possible to the flowering plants, for the purpose of blowing the pollen from one blossom to the other, and even to gather the barren kind and place it over that destined to bear fruit. The oeconomy of various aquatic plants throws great light upon the subject before us. Different species of Potamogeton, Engl. Bot. t. 168, 297, 376, &c, Ruppia maritima, t. 136, and others, float entirely under water, often at some considerable depth, till the flowering season arrives, when they rise near the surface, and throw up their flowering spikes above it, sinking afterwards to ri- pen and sow their seeds at the bottom, Nymphaa alba,t. 160, is very truly described by Linnaeus in his FloraSue- cica,as closing its flowers in the afternoon and laying them down upon the surface of the water till morning, when it raises and expands them, often, in a bright day, to seve- ral inches above the water. To this I can speak from my own knowledge, and it is confirmed by the history given by Theophrastus of his Lotus, which, according to all appearance, is the Nymphaa Lotus of Linnaeus. " This," says he, " as well as the Cyamus*, bears its fruit in a head. The flower is white, consisting of • Exot Pot. t. 31, 32. OF THE NYMPHJEA. 261 many crowded leaves about as broad as those of a lily. These leaves at sunset fold themselves together, cover- ing the head (or seed-vessel). At sun-rise they expand, and rise above the water. This they continue till the head is perfected, and the flowers fall off." So far Theophrastus writes as of his own knowledge ; he con- tinues as follows ; " It is reported that in the Euphrates the head and flowers keep sinking till midnight, when they are so deep in the water as to be out of reach of the hand, but towards morning they return, and still more as the day advances. At sun-rise they are already above the surface, with the flower expanded; afterwards they rise high above the water." Pliny repeats the same account ; and Prosper Alpinus, whose purpose is to prove the Lotus of Theophrastus not different from the common Nymphaa, in which, as far as genus is concerned, he is correct, has the following remarkable passage : " The celebrated stories of the Lotus turning to the sun, closing its flowers and sinking under water at night, and rising again in the morning, are conformable to what every body has observed in the Nymphaa." I have been the more particular in the above quota- tions.because the veracity of Theophrastus has lately been somewhat rudely impeached, on very questionable au- thority. For my own part, I think what we see of the Nymphaa in England is sufficient to render the above ac- count highly probable in a country where the sun has so much more power, even if it did not come from the most faithful and philosophical botanist of antiquity, and I have always with confidence cited it on his authority. The reader, however, will perceive that the only important 20* OF THE VALISNERIA. circumstance for our purpose is the closing of the flow- ers at night, which is sufficiently well established. But the most memorable of aquatic plants is the Valis- neria spiralis, well figured and described by Micheli, Nov. Gen. t. 10, which grows at the bottoms of ditches in Italy. In this the fertile flowers stand on long spiral stalks, and these by uncoiling elevate them to the surface of the water, where the calyx expands in the open air. In the mean while plenty of barren flowers are produced on a distinct root, on short straight stalks, from which they rise like little separate white bubbles, suddenly ex- panding when they reach the surface, and floating about it in such abundance as to cover it entirely. Thus their pollen is scattered over the stigmas of the first- mentioned blossoms, whose stalks soon afterwards rt- sume their spiral figure, and the fruit comes to maturity at the bottom of the water. All this Micheli has de- scribed, without being aware of its final purpose ; so dif- ferent is it to observe and to reason ! Some aquatic vegetables, which blossom under water, seem to have a peculiar kind of glutinous pollen, des- tined to perform its office in that situation, as Chara, Engl. Bot. t. 336, &c. ; as well as the Fucus and Con- ferva tribe : but of the real nature of the fructification of these last we can at present only form analogical con- jectures. The fertilization of the Fig is accomplished in a strik- ing manner by insects, as is that of the real Sycamore, Ficus Sycomorus. In this genus the green fruit is a hol- low common calyx, or rather receptacle, lined with va- rious flowers seldom both barren and fertile in the same ASSISTANCE OF INSECTS IN IMPREGNATION. 263 fig. This receptacle has only a very small orifice at the summit. The seeds therefore would not in general be perfected were it not for certain minute flies of the ge- nus Cynips, continually fluttering from one fig to the other, all covered with pollen, and depositing their eggs within the cavity. A very curious observation is recorded by Schreber and Willdenow concerning the Aristolochia Clematitis, Engl. Bot. t. 398. The stamens and pistils of this flow- er are enclosed in its globular base, the anthers being under the stigma, and by no means commodiously situ- ated for conveying their pollen to it. This therefore is accomplished by an insect, the Tipula pennicornis, which enters the flower by the tubular part. But that part be- ing thickly lined with inflexed hairs, though the fly en- ters easily, its return is totally impeded, till the corolla fades, when the hairs lie flat against the sides, and allow the captive to escape. In the mean while the insect, continually struggling for liberty, and pacing his prison round and round, has brushed the pollen about the stig- ma. I do not doubt the accuracy of this account, though I have never caught the imprisoned Tipula. In- deed I have never seen any fruit formed by this plant. Probably for want of some insect adapted to the same purpose in its own country, the American Aristolochia Sipho, though it flowers plentifully, rarely forms fruit in our gardens. That it sometimes does, I have been in- formed by Lady Amelia Hume, since the first edition of this work was published. The ways in which insects serve the same purpose are innumerable. These active little beings are peculiarly 264 ASSISTANCE OF INSEOTS IN IMPREGNATION. busy about flowers in bright sunny weather, when every blossom is expanded, the pollen in perfection, and all the powers of vegetation in their greatest vigour. Then we see the rough sides and legs of the bee, laden with the golden dust which it shakes off, and collects anew, in its visits to the honeyed stores inviting it on every side. All Nature is then alive, and a thousand wise ends are accomplished by innumerable means that " seeing we perceive not;" for though in the abundance of creation there seems to be a waste, yet in proportion as we understand the subject, we find the more reason to conclude that nothing is made in va?" [ 265 ] CHAPTER XXI. ON THE DISEASES OF PLANTS, PARTICULARLY AS ILLUSTRA- TIVE OF THEIR VITAL PRINCIPLE. The diseases of Vegetables serve in many instances to prove their vitality, and to illustrate the nature of their constitution. Plants are subject to Gangrene or Sphacelus, especial- ly the more succulent kinds, of which a very curious ac- count, concerning the Cactus coccinellfer, Indian Fig, or Nopal, extremely to our present purpose, is given by M. Thiery de Menonville, in his work on the culture of the Nopal as the food of the Cochineal insect. This writer travelled about twenty years since, through the Spanish settlements in South America, chiefly noted for the cultivation of this precious insect, on purpose to transport it clandestinely to some of the French islands. Such were the supineness and ignorance of the Span- iards, that he succeeded in conveying not only the liv- ing insects, but the bulky plant necessary for their sus- tenance, notwithstanding severe edicts to the contrary. He had attended previously to tha management of the Nopal, and made his remarks on the diseases to which.it is liable. Of these the Gangrene is extremely frequent in the true Nopal of Mexico, beginning by a black spot, which spreads till the whole leaf or branch rots off, or the shrub dies. But the same kind of plant is often af- fected with a much more serious disease, called by Thie- KK ~t)b GANGRENE OF PLANTS. ry " la dissolution." This seems to be a sudden decay of the vital principle, like that produced in animals by lightning or strong electricity. In an hour's time, from some unknown cause, a joint, a whole branch, or some- times an entire plant of the Nopal, changes from appar- ent health to a state of putrefaction or dissolution. One minute its surface is verdant and shining ; the next it turns yellow, and all its brilliancy is gone. On cutting into its substance, the inside is found to have lost all co- hesion, being quite rotten. The only remedy in this case is speedy amputation below the diseased part. Sometimes the force of the vital principle makes a stand, as it were, against the encroaching disease, and throws off the infected joint or branch. Such is the ac- count given by Thiery, which evinces a power in vege- tables precisely adequate to that of the animal constitu- tion, by which an injured or diseased part is, by an effort of Nature, thrown off to preserve the rest. Nor need we travel to Mexico to find examples of this. Every deciduous tree or shrub exhibits the very same phoenomenon ; for the fall of their decaying foli- age in autumn, leaving the branches and young buds vigorous and healthy, can be explained in no other way. Yet Du Hamel laboured in vain to account for the fall of the leaf ;* nor is it wonderful that he or any body else, who endeavours to explain the physiology of vegeta- bles or of animals, according to one principle only, whether it be mechanical or chemical, should entirely fail. To consider the fall of leaves in autumn as a sloughing, or casting off diseased and worn out parts, " See his Phys. des Arbres, v. 1. 127. FALL OF THE LEAF. 267 seems so simple and evident, as to be hardly worth insist- ing upon. Yet I find myself anticipated in this theory by one physiologist only, named Vrolick, cited by Willdenow in his Principles of Botany, p. 304, though several learned speculations to no purpose are extant on the subject. It is but just, however, that I should re- late what led me to consider the matter with any atten- tion. My observing friend Mr. Fairbairn of Chelsea garden long ago remarked to me, that when he had oc- casion to transplant any tree or shrub whilst in leaf, he could soon judge of its success by the ease with which its leaves were detached. The consequence of such treatment is more or less injury to the health of the plant, as will first appear by the drooping of the leaves, most of which will probably die, and .the decay will generally be extended to the younger more delicate twigs. The exact progress of this decay may speedily be known, by the leaves of those branches which are ir- recoverably dying or dead, remaining firmly attached, so as not to be pulled off without a force sufficient to bring away the bark or buds along with them : whereas the leaves of parts that have received no material injury, and where the vital energy acts with due power, either fall off spontaneously, or are detached by the slighest touch. Plants of hot countries, kept in our stoves, exhibit the same phenomenon, when transplanted or otherwise in- jured; even though not naturally deciduous. So when fruits are thoroughly ripened, they become, with respect to the parent plant, dead substances, and, however strongly attached before, are then thrown off as extraneous bodies. Their stalks fade or wither, though 268 FALL OF RIPE FRUlT. the life of the adjoining branch continues unimpaired, and a line of separation is soon drawn. In a poor soil* or unfavourable climate, a bunch or spike which should naturally consist of a considerable number of flowers, bears perhaps not half so many. Its upper part very early withers, the vital principle ceases to act at the point beyond which it could not continue to act with effect, and all its energy is directed to perfect what lies within the compass of its resources. This is evident in Lathy- rus odoratus, the Sweet Pea of our gardens, a native of a very hot climate, at the summits of whose flower- stalks are generally found the rudiments of one or more flowers, not attempted to be perfected. So also the first Barley sown on the sandy heaths of Norfolk, and indeed too many a following crop, bears very few grains in an ear ; for the same meagre supply of nourishment, be- stowed equally on a numerous spike of blossoms, would infallibly starve them all. In like manner one seed only is perfected in the best wild Arabian Coffee, known by its round form ; while the West Indian plantation Cof- fee has two in each berry, both consequently flattened on one side. The former grows in barren open places, in situations sufficiently favourable for the impregna- tion of its blossoms, but far less so for the perfecting of much seed ; while the latter, well supplied with manure and moisture, is enabled to bring every germ to maturity. Very strange effects are often produced upon plants by the attacks of insects, whence the various kinds of Galls derive their origin. These are occasioned by the OF GALLS AND VARIOUS EXCRESCENCES. 269 punctures of those little animals, chiefly of the Hymen- optera order, and of the genus Cynips, in some vigorous part of the plant, as the leaves, leaf-stalks, young stem or branches, and sometimes the calyx or germen. The parent insect deposits its egg there, which is soon hatch- ed, and in consequence of the perpetual irritation occa- sioned by the young maggot, feeding on the juices of the plant, the part where it is lodged acquires a morbid degree of luxuriance, frequently swelling to an immod- erate size, and assuming the most extraordinary and whimsical shapes. This often happens to the shrubby species of Hawk weed, Hieracium sabaudum, Engl. Bot. t. 349, and umbellatum, t. 1771, whose stems in conse- quence swell into oval knots. Several different kinds of Galls are borne by the Oak, as those light spongy bod- ies, as big as walnuts, vulgarly named Oak apples ; a red juicy berry-like excrescence on its leaves ; and the very astringent Galls brought from the Levant, for the purposes of dyeing and making ink, which last are pro- duced by a different species of Quercus from either of our own. The common Dog-rose, t. 992, frequently bears large moss-like balls, in whose internal parts nume- rous maggots are always to be found, till they become the winged Cynips Rosa, and eat their way out. Many of our Willows bear round excrescences, (116) as large as peas, on their leaves ; but I remember to have been very much astonished in Provence with a fine branched pro- duction on the Willows in winter, which appeared like a (116) [Very singular spongy or juicy excrescences are produ- ced from some American 6hrubs of the genus Andromeda and Azalea ; caused, no doubt, by insects.] 270 REMARKABLE EXCRESCENCES. tufted Lichen, but proved on examination a real Gall. Indeed our Salix Helix, t. 1343, is called Rose Willow from its bearing no less remarkable an excrescence, like a rose, at the ends of some of its branches, in conse. quence of the puncture of an insect, and these are in like manner durable, though the proper leaves fall. The Mastic-tree, Pistacia Lentiscus, is often laden, in the south of Europe, with large red hollow finger-like bod- ies, swarming internally with small insects, the Aphis Pistacia of Linnaeus. The young shoots of Salvia po- mifera, Fl. Grac. t. 15, S. triloba, t. 17, and even S. officinalis, in consequence of the attacks probably of some Cynips, swell into large juicy balls, xery like ap. pies, and even crowned with rudiments of leaves resem- bling the calyx of that fruit. These are esteemed in the Levant for their aromatic and acid flavour, especially when prepared with sugar. It may be remarked that all the excrescences above mentioned are generally more acid than the rest of the plant that bears them, and also greatly inclined to turn red. The acid they contain is partly acetous, but more of the astringent kind. The diseases of the skin, to which many vegetables are subject, are less easily understood than the forego- ing. Besides one kind of Honey-dew, already mention- ed, p. 157, something like leprosy may be observed in Tragopogon major, Jacq. Austr. t. 29, which as I have been informed by an accurate observer, does not injure the seed, nor infect the progeny. The stem of Shep- herd's Purse, Engl. Bot. t. 1485, is occasionally swel- led, and a white cream-like crust, afterwards powdery, OF THE BLIGHT AND SIMILAR DISEASES. 271 ensues. The White Garden Rose, Rosa alba, produ- ces, in like manner, an orange-coloured powder. It proves very difficult, in many cases, to judge whether such appearances proceed from a primary disease in the plant, arising from unseasonable cold or wet, or are owing to the baneful stimulus of parasitical fungi irritating the vital principle, like the young progeny of insects as above related. Sir Joseph Banks has, with great care and sagacity, traced the progress of the Blight in Corn, Uredo fumenti, Sowerb. Fung. t. 140, and given a com- plete history of the minute fungus which causes that appearance. See Annals of Botany, v. 2. 51, t. 3, 4. Under the inspection of this eminent promoter of sci- ence, Mr. Francis Bauer has made microscopical draw- ings of many similar fungi infecting the herbage and seeds of several plants, but has decided that the black swelling of the seed of corn, called by the French Ergot, though not well distinguished from other appearances by the generality of our agricultural writers, is indubitably a morbid swelling of the seed, and not in any way con- nected with the growth of a fungus. The anthers of certain plants often exhibit a similar disease, swelling, and producing an inordinate quantity of dark purplish powder, instead of true pollen, as happens in Silene in- flata, Fl. Brit. Engl. Bot. t. 164, and the white Lych- nis dioica, t. 1580, whose petals are, not uncommonly, stained all over with this powder. Our knowledge on all these subjects is yet in its infancy; but it is to hoped, now the pursuit of agriculture and of philosophical bot- any begin to be, in some distinguished instances, united, such examples will be followed, and science directed to 27J OF THE BLIGHT AND SIMILAR DISEASES. one of its best ends, that of improving useful arts. And here I cannot but mention the experiments continually going on under the inspection of the ingenious Mr. Knight, of fertilizing the germen of one species or vari- ety with the pollen of another nearly akin, as in apples, garden peas, &c, by which, judiciously managed, the advantages of different kinds are combined. By the same means Linnaeus obtained intermediate species or varieties of several plants : and if any thing were want- ing to confirm his theory respecting the stamens and pistils, this alone would place it out of all uncertainty. [ 273 ] CHAPTER XXII. OF THE SYSTEMATICAL ARRANGEMENT OF PLANTS. NATU. RAL AND ARTIFICIAL METHODS. GENERA, SPECIES, AND VARIETIES. NOMENCLATURE. The foregoing chapters have sufficiently explained the parts of plants, and the leading differences in their conformation, for us now to proceed to the Systematical part of our subject. In this, when properly understood and studied, there is no less exercise for the mind, no less employment for its observation and admiration, than in physiological or anatomical inquiries ; nor are the organs of vegetables, when considered only as instru- ments of classification and discrimination, less conspicu- ous for beauty, fitness, and infinite variety of contri- vance, than under any other point of view. The wis- dom of an Infinite Superintending Mind is displayed throughout Nature, in whatever way we contemplate her productions. When we take into consideration the multitude of species which compose the vegetable kingdom, even in any one country or climate, it is obvious that some ar- rangement, some regular mode of naming and distin- guishing them, must be very desirable, and even neces- sary, for retaining them in our own memory, or for com- municating to others any thing concerning them. Yet the antients have scarcely used any further classification of plants than the vague and superficial division into LL 274 OF BOTANICAL ARRANGEMENT. trees, shrubs and herbs, except a consideration of their places of growth, and also of their qualities. The earli- er botanists among the moderns almost inevitably fell into some rude arrangement of the objects of their study, and distributed them under the heads of Grasses, Bulbous plants, Medicinal or Eatable plants, &c, in which their successors made several improvements, but it is not worth while to contemplate them. The science of Botanical Arrangement first assumed a regular form under the auspices of Conrad Gesner and Caesalpinus, who, independent of each other, without any mutual communication, both conceived the idea of a regular classification of plants, by means of the parts of fructification alone, to which the very existence of Bota- ny as a science is owing. The first of these has left us scattered hints only, in various letters, communicated to the world after his premature death in 1565 ; the latter published a system^ founded on the fruit, except the primary division into trees and herbs, in a quarto vol- ume printed at Florence in 1583. This work Linnaeus studied with great care, as appears from the many notes and marked passages in his own copy now before me. Hence he adopted his ideas of the supposed origin of the calyx, corolla, stamens, and pistils, from the outer bark, inner bark, wood and pith, which are now proved to be erroneous. In his own Classes Plantarum he has drawn out a regular plan of the System of Caesalpinus, the chief principles of which are the following: 1. Whether the embryo be at the summit or base of the seed. METHODS OF CJESALPINUS, RFvTNUS, &c 275 2. Whether the germen be superior or inferior. ,3. Seeds, 1, 2, 3, 4, or numerous. 4. Seed-vessels, 1, 2, 3, 4, &c. The work of Caesalpinus, though full of information, was too deep to be of common use, and excited but lit- tle attention. A century afterwards Morison, Professor of Botany at Oxford, improved somewhat upon the ideas of the last-mentioned writer, but has been justly blamed for passing over in silence the source of his own information. Ray, the great English naturalist, formed a considerably different system upon the fruit, as did Hermann, Professor at Leyden, and the great Boer haave, but in these last there is little originality. Rivinus, Ruppius and Ludwig in Germany proposed to arrange plants by the various forms of their Corolla, as did Tournefort the illustrious French botanist, whose system is by far the best of the kind ; and this having been more celebrated than most others, I shall give a sketch of its plan. In the first place we meet with the old but highly un- philosophical division into Herbs and Trees, each of which sections is subdivided into those with a Corolla and those without. The Trees with a Corolla are again distributed into such as have one or many petals, and those regular or irregular.—Herbs with a Corolla have that part either compound (as the Dandelion, Thistle and Daisy), or simple; the latter being either of one or many petals, and in either case regular or irregu- lar. We come at last to the final sections, or classes, of the Tournefortian system. Herbs with a simple, mo 2?d METHODS OF TOURNEFORT, nopetalous, regular corolla are either bell-shaped or fun- nel-shaped ; those with an irregular one either anoma- lous or labiate. Herbs with a simple, polypetalous regular corolla are either cruciform, rosaceous, umbellate, pink-like or lilia- ceous ; those with an irregular one, papilionaceous or anomalous. * The subdivisions of the classes are found- ed on the fruit. It is easy to perceive that a system of this kind can never provide for all the forms of corolla which may be discovered after its first contrivance ; and therefore the celebrated Dr. Garden, who studied by it, assured me that when he attempted to reduce the American plants to Tournefort's classes, he found them so untractable, that, after attempting in vain to correct or augment the system, he should probably have given up the science in despair, had not the works of Linnaeus fallen in his way. Magnol, Professor at Montpellier, and even Linnaeus himself, formed schemes of arranging plants by the ca- lyx, which nobody has followed. All preceding systems, and all controversies respect- ing their superior merits, were laid aside, as soon as the famous Linnaean method of classification, founded on the Stamens and Pistils, became known in the botanical world. Linnaeus, after proving these organs to be the most essential of all to the very being of a plant,first con- ceived the fortunate idea of rendering them subservient to the purposes of methodical arrangement, taking into consideration their number, situation and proportion. MAGNOL, AND LINNiEUS. 277 How these principles are applied, we shall presently ex- plain ; but some previous observations are necessary. Linnaeus first made a distinction between a natural and an artificial method of botanical arrangement. His predecessors probably conceived their own systems to be each most consonant with the order of Nature, as well as most commodious for use, and it was reserved for him to perceive and to explain that these were two very distinct things. The most superficial observer must perceive some- thing of the classification of Nature. The Grasses, Umbelliferous plants, Mosses, Sea-weeds, Ferns, Lilia- ceous plants, Orchises, Compound flowers, each consti- tute a family strikingly similar in form and qualities among themselves, and no less evidently distinct from all others. If the whole vegetable kingdom could with equal facility be distributed into tribes or classes, the study of Botany on such a plan would be no less easy than satisfactory. But as we proceed in this path, we soon find ourselves in a labyrinth. The natural orders and families of plants, so far from being connected in a regular series, approach one another by so many points, as to bewilder instead of directing us. We may seize some striking combinations and analogies ; but the fur- ther we proceed, the more we become sensible that, even if we had the whole vegetable world before us at one view, our knowledge must be imperfect, and that our " genius" is certainly not " equal to the majesty of Na- ture." Nevertheless Linnaeus, and all true philosophi- cal botanists since the first mention of the natural affini- ties of plants, have ever considered them as the most 278 NATURAL MODE OF CLASSIFICATION. important and interesting branch, or rather the funda- mental part, of systematical botany. Without them the science is truly a study of words, contributing nothing to enlarge, little worthy to exercise, a rational mind. Lin- naeus therefore suggests a scheme which he modestly calls Fragments of a Natural Method, which formed the subject of his occasional contemplation ; but he dai- ly and hourly studied the principles of natural affinities among plants, conscious that no true knowledge of their distinctions, any more than of their qualities, could be obtained without; of which important truth he was not only the earliest, but even the most strenuous assertor. In the mean while, however, Linnaeus, well aware that a natural classification was scarcely ever to be com- pletely discovered, and that if discovered it would prob- ably be too difficult for common use, contrived an artifi- cial system, by which plants might conveniently be ar- ranged, like words in a dictionary, so as to be most readily found. If all the words of a language could be disposed according to their abstract derivations, or gram- matical affinities, such a performance might be very in- structive to a philosopher, but would prove of little ser- vice to a young scholar; nor has it ever been mentioned as any objection to the use of a dictionary, that words of very different meanings, if formed of nearly the same let- ters, often stand together. The method of Linnaeus therefore is just such a dictionary in Botany, while his Philosophia Botanica is the grammar, and his other works contain the history, and even the poetry, of the cience. LINNiEAN ARTIFICIAL METHOD. 279 But before we give a detail of his artificial system, we must first see how this great man fixed the fundamental principles of botanical science. Nor are these princi- ples confined to botany, though they originated in that study. The Linnaean style of discriminating plants, has been extended by himself and others to animals and even fossils ; and his admirable principles of nomencla- ture are applied with great advantage even to chemistry itself, now become so vast and accurate a science. Independently of all general methods of classification, whether natural or artificial, plants, as well as animals, are distinguished into Genera*, Species and Varieties. By Species are understood so many individuals, or, among the generality of animals, so many pairs, as are presumed to have been formed at the creation, and have been perpetuated ever since ; for though some animals appear to have been exterminated, we have no reason to suspect any new species has been produced ; neither have we any cause to suppose any species of plant has been lost, nor any new one permanently established, since their first formation, notwithstanding the specula- tions of some philosophers. We frequently indeed see new Varieties, by which word is understood a variation in an established species ; but such are imperfectly, or for a limited time, if at all, perpetuated in the offspring. A Genus comprehends one or more species, so es- sentially different in formation, nature, and often many * Our scientific language in English is not sufficiently perfect to afford a plural for genus, and we are therefore obliged to adopt the Latin one, genera, though it exposes us sometimes to the horrors of hearing of « a new genera" of plants. 280 OF GENERA AND adventitious qualities, from other plants, as to constitute a distinct family or kind, no less permanent, and found- ed in the immutable laws of the creation, than the dif- ferent species of such a genus. Thus in the animal kingdom, a horse, ass and zebra form three species of a very distinct genus, marked, not only by its general habit or aspect, its uses and qualities, but also by essen- tial characters in its teeth, hoofs, and internal constitu- tion. The lion, tiger, leopard, panther, lynx, cat, &c, also compose another sufficiently obvious* and natural genus, and the numerous herd of monkeys, apes and baboons a third. The elephant is, as far as we know, a solitary species of a mcJSt distinct and striking genus. So among vegetables, the various species of rose com- pose a beautiful genus, known to every one who ever looked at a plant, merely by a certain combination of ideas, but essentially distinguished, as we shall hereafter find, by clear and decisive characters. The species of Iris form also a numerous genus, and the Willows an- other ; while the curious Epimedium alpinum, Engl. Bot. t. 438, is too singular and distinct to be associated with any known plant besides, and constitutes a genus by itself, as well as the Adoxa, t. 453, and Linnaa, t. 433. The first great and successful attempt to define the genera of plants was made by Tournefort, and in this his transcendent merit will ever be conspicuous, though his system of arrangement should be entirety forgotten. Not that he has excelled in verbal definitions, nor built all rns genera on sure foundations ; but his figures, and his enumerations of species under each genus, show the THEIR CHARACTERS. SSI clearness of his conceptions, and rank him as the father of this branch of botany. Linnaeus first insisted on generic characters being exclusively taken from the 7 parts of fructification, and he demonstrated these to be sufficient, for all the plants that can be discovered. He also laid it down as a max- im, that all genera are as much founded in nature as the species which compose them ; and hence follows one of the most just and valuable of all his principles, that a ge- nus should furnish a character, not a character form a genus ; or, in other words, that a certain coincidence of structure, habit, and perhaps qualities, among a number of plants, should strike the judgment of a botanist, before he fixes on one or more technical characters, by which to stamp and define such plants as one natural genus. Thus the Hemerocallis carulea, Andr. Repos. t. 6, and alba, t. 194, though hitherto referred by all botanists to that genus, are so very different from the other species in habit, that a discriminative character might with con- fidence be expected in some part or other of their fructi- fication, and such a character is accordingly found in the winged seeds. Yet in the natural genera of Arena- ria and Spergula, winged or bordered seeds are so far from indicating a distinct genus, that it is doubtful whether they are sufficient to constitute even a specific character. See Engl. Bot. t. 958,1535 and 1536. So Blandfordia, Exot. Bot. t. 4, is well distinguished from Aletris, with which some botanists have confounded it, by its hairy seeds ; but the same circumstance will not justify us in separating a few species from Convolvulus, MM -3: CHARACTERS which are attached to that genus by stronger ties of an- other kind. Some genera are obvious and indubitable both in habit and character, as Quercus, Rosa, Euphorbia, Be- gonia, Exot. Bot. t. 101, and Sarracenia, t. 53 ; others are obvious, but their character extremely difficult to define, as Valeriana. The greatest difficulty lies in dis- tinguishing genera that belong to such very natural or- ders as the Grasses and Umbelliferous plants ; and the ablest botanists differ about the best guides in these two particular cases. Yet other orders, equally natural, sometimes afford very excellent generic differences," as that to which Rosa, Rubus, Fragaria, &c, belong; and even in the Papilionaceous plants with ten distinct sta- mens, a tribe hitherto judged inextricable, a regular ex- amination on scientific principles has led to the discovery of very natural well defined genera. See Annals of Botany, v. 1. 501. I have in a preceding chapter hinted that the umbelliferous plants seem to me verv capable of being well discriminated by their seeds, and other botanists have held the same opinion. But though I feel convinced, as far as my experience goes, that genera are really founded in nature, I am far from asserting that Linnaeus, or any other writer, has succeeded in fixing all their just limits. This deep and important branch of natural science requires the union of various talents. Many persons who can perceive a genus cannot define it ; nor do acuteness of perception, solidity of judgment, and perspicuity of expression, always meet in the same person. Those who excel in this department are named by Linnaeus, Phil. Bot. sect. OF GENERA. 283 i52, theoretical botanists ; those who study only species and varieties, practical ones. In methodical arrangement, whether natural or artifi- cial, every thing must give way to generic distinctions. A natural system which should separate the species of a good genus, would,by that very test alone, prove entirely worthless ; and if such a defect be sometimes unavoid- able in an artificial one, contrivances must be adopted to remedy it; of which Linnaeus has set us the example, as will hereafter be explained. Generic characters are reckoned by Linnaeus of three kinds, the factitious, the essential, and the natural, all founded on the fructification alone, and not on the inflo- rescence, nor any other part. The first of these serves only to discriminate genera that happen to come together in the same artificial or- der or section ; the second to distinguish a particular genus, by one striking mark, from all of the same natu- ral order, and consequently from all other plants ; and the third comprehends every possible mark common to all the species of one genus. The factitious character can never stand alone, but may sometimes, commodiously enough, be added to more essential distinctions, as the insertion of the petals in Agrimonia, Engl. Bot. t. 1335, indicating the natur- al order to which the plant belongs, which character, though essential to that order, here becomes factitious. Linnaeus very much altered his notions of the essen- tial character after he had published his Philosophia Bo- tanica, whence the above definitions are taken. Instead of confining it to one mark or idea, he, in his Systema '■k 264 OF ESSENTIAL Vegetabilium, makes it comprehend all the distinctions requisite to discriminate each genus from every other in the system, only avoiding a repetition at every step of the characters of the artificial class and order, which stand at the top of each page, and are not always essen- tial to the character of the genus. This is the kind of generic character now universally adopted, and indeed the only one in common use. The learned Jussieu has given it the sanction of his approbation and adoption, as far as its plan is concerned, throughout his immortal work, subjoining in a different type such characters and remarks as belong to the habit, or refer to other circum- stances. For my own part, I profess to retain, not only the plan, bui the very words of Linnaeus, unless I find them erroneous, copying nothing without examination, but altering with a very sparing hand, and leaving much for future examination. I cannot blame my predeces- sors for implicitly copying the Linnean characters, nor should I have been the first among English writers to set a contrary example, had I not fortunately been fur- nished with peculiar materials for the purpose. The beauty and perfection of these essential generic characters consist in perspicuity, and a clear concise style of contrasting them with each other. All feeble- ness, all superfluity, should be avoided by those who are competent to the purpose, and those who are not should decline the task. Comparative words, as long or short, without any scale of comparison, are among the gross- est, though most common, faults in such compositions. The natural character seems to have been, at one time, what Linnaeus most esteemed. It is what he has & GENERIC CHARACTERS. J85 used throughout his Genera Plantarum, a work now su- perseded by the essential characters in his Systema Veg- etabilium, and therefore in some measure laid aside. The disadvantages of the natural character are, that it does not particularly express, nor direct the mind to, the most important marks, and that it can accord only with such species of the genus as are known to the author, being therefore necessarily imperfect. This kind of character is, however, admirable for the illustration of any difficult natural order. Mr. Gawler's elucidations of the Ensata, Sword-leaved plants, Annals of Botany, v. 1. 219, and Curt. Mag. afford excellent specimens of it, serving as a store of facts and observations for follow- ing systematical writers. Specific characters should be constructed on similar principles to the generic ones, as far as regards certainty, clearness and conciseness. The genus being first well defined, we are to seek for characters, not mentioned among the generic marks, for distinguishing the species. A specific difference for a solitary species of any genus, is therefore an absurdity. Linnaeus at first intended his specific definitions should be used as names ; but the in- vention of trivial names happily set aside this inconve- nient scheme. On this account however he limited each to twelve words, a rule to which all philosophical naturalists have adhered, except in cases of great neces- sity. Nor is the admission of one or two words beyond the allotted number reprehensible, provided the whole sentence be so neatly and perspicuously constructed; that the mind may comprehend it, and compare it with others at one view ; but this can hardly be done when 286 CONSTRUCTION OF SPECIFIC CHARACTERS. the words much exceed twelve. This rule, of course, can be strictly applied to Latin definitions only, though it should be kept in view in any lan- guage, as far as the genius of that language will allow. Linnaeus says, " Genuine specific distinc- tions constitute the perfection of natural science ;" which is strongly confirmed by the great inferiority of most botanists, in this department, to that great man, and especially by that tedious feebleness and insufficien- cy displayed among those who court celebrity by despis- ing his principles. In constructing generic and specific characters, the arrangement of the different parts on which they are founded is to be considered. Such as are most impor- tant in the natural order, or genus, are to stand first, and the subordinate, or more peculiar marks of the object before us, ought to close the sentence. On the contrary, in drawing up natural characters of a ge- nus, as well as full descriptions of particular plants, it is proper to take, in the former instance, the calyx, corolla, stamens, pistils, seed-vessel, seed and receptacle, and in the latter, the root, stem, leaves, appendages, flower and fruit, in the order in which they naturally occur. Nomenclature is no less essential a branch of method- ical science than characteristic definitions ; for, unless some fixed laws, or, in other words, good sense and per- spicuity, be attended to in this department, great confu- sion and uncertainty must ensue. The vague names of natural objects handed down to us, in various languages, from all antiquity, could have PRINCIPLES OF NOMENCLATURE. 287 no uniformity of derivation or plan in any of those lan- guages. Their different origins may be imagined, but cannot be traced. Many of these, furnished by the Greek or Latin, are retained as generic names in scien- tific botany, though neither their precise meaning, nor even the plants to which they originally belonged, can always be determined, as Rosa, Ficus, Piper, &c. It is sufficient that those to which they are now, by common consent, applied, should be defined and fixed. Bota- nists of the Linnaean school, however, admit no such generic names from any other language than the Greek or Latin, all others being esteemed barbarous. With- out this rule we should be overwhelmed, not only with a torrent of uncouth and unmanageable words, but we should be puzzled where to fix our choice, as the same plant may have fifty different original denominations in different parts of the world, and we might happen to choose one by which it is least known. Thus the cele- brated Indian plant, now proved beyond all doubt to be the Cyamus of Theophrastus*, having been erroneously reckoned by Linnaeus a Nymphaa, received from Gaert- ner, one of the first who well distinguished it as a genus, the Ceylon name of Nelumbo ; which being contrary to all rules of science, literature or taste for a generic name, has by others been made into bad Latin as Nelumbium. But the universal Hindu name of the plant is Tamara, * See Exot. Bot. v. 1. 60, where the arguments in support of this opinion are given, and Curt. Mug. t. 903, where some of them are with much candour and ingenuity controverted, though not so as to alter my sentiments ; nor can any thing justify the use of JVehanbium in a scientific work as a generic name. .288 OF BARBAROUS NAMES which, independent of barbarism, ought to have been preferred to the very confined one of Nelumbo. In like manner the Bamboo, Arundo Bambos of Linnaeus, prov- ing a distinct genus, has received the appellation of Batnbusa, though Jussieu had already given it that of Nastus, from Dioscorides*. Perhaps the barbarous name of some very local plants, when they cannot pos- sibly have been known previously by any other, and when that name is harmonious and easily reconcileable to the Latin tongue, may be admitted, as that of the Ja- pan shrub Aucuba ; but such a word as Ginkgo is in- tolerable. The Roman writers, as Cesar, in describing foreign countries, have occasionally latinized some words or names that fell in their way, which may possi- bly excuse our making Ailanthus of Aylanto, or Pan- danus of Pandang. Still I can only barely tolerate such names out of deference to the botanical merits, not the learning, of their contrivers; and I highly honour the zeal and correctness of Mr. Salisbury, who, in de- fiance of all undue authority, has ever opposed them, naming Aucuba, on account of its singular base or re- ceptacle, Eubasis. I know not how Pandanus escaped his reforming hand especially as the plant has already a good characteristic Greek name in the classical Forster, Athrodactylis. " It is not indeed clear that this name is so correctly applied as that of Cyamus, because Nastus originally belonged to « a reed with a solid stem," perhaps a palm ; but not being wanted, nor capable of being correctly used, for the latter, it may very well serve for the Bamboo. There is no end of raking up old uncertainties about classical names. OF GREEK OR LATiN NAMES. 2SS Excellent Greek or Latin names are such as indicate some striking peculiarity in the genus : as Glycyrrhiza, a sweet root, for the Liquorice ; Amaranthus, without decay, for an everlasting flower: Helianthus, asunflow- er ; Lithospermums a stony seed ; Eriocalia*, a flower with a singularly woolly base or cup ; Origanum, an ornamental mountain plant; Hemerocallis, a beauty of a day ; Arenaria, a plant that inhabits sandy places; and Gypsophita, one that loves a chalky soil. Such as mark the botanical character of the genus, when they can be obtained for a nondescript plant, are peculiarly desira- ble : as Ceratopetalum, from the branched hornlike pe- tals ; Lasiopetalum, from the very singular woolly corol- la ; Calceolaria, from the shoe-like figure of the same part i Conchium, from, the exact resemblance of its fruit to a bivalve shell. In all ages it has been customary to dedicate certain plants to the honour of distinguished persons. Thus Euphorbia commemorates the physician of Juba a Moor- ish prince, and Gentiana immortalizes a king of Illyria. The scientific botanists of modern times have adopted the same mode of preserving the memory of benefactors to their science ; and though the honour may have been sometimes extended too far, that is no argument for its total abrogation. Some uncouth names thus unavoida- bly deform our botanical books j but this is often effa- * When I named this genus in Exotic Botany, I was not aware of its having previously been published by M. Billardierc under the name of Actinotus ; a name however not tenable in "Botany, because it has long been preoccupied in Mineralogy. N.V ^» GENERIC NAMES IN eed by the merit of their owners, and it is allowable to model them into grace as much as possible. Thus the elegant Tournefort made Gundelia from Gundelschei- mer; which induced mc to choose Goodenia, for my much honoured and valued friend Dr. Goodenough, though it has, when too late, been suggested that Goode- novia, might have been preferable. Some difficulty has arisen respecting French botanists on account of the ad- ditional names by which their grandeur, or at least their Vanity, was displayed during the existence of the mon- archy. Hence Pittonia was applied to the plant conse- crated to Pitton de Tournefort; but Linnaeus preferred the name by Which alone he was known out of his own Country or in learned language, and called the same genus Tournefortia. Thus we have a Fontainesia and a Louichea, after the excellent Louiche Desfontaines ; but the latter proving a doubtful genus, or, if a good one, being previously named Pteranthus, the former is es- tablished. We have even in England, by a strange oversight, both Stuartia and Butea after the famous Earl of Bute ; but the former being long ago settled by Linnaeus, the latter, since given by Kcenig, is totally inadmissible on any pretence whatever, and the genus which bears it must have a new appellation. In like manner my own Humea, Exot. Bot. t. 1, has been call- ed in France Calomeria after the present Emperor, by the help of a pun, though there has long been another genus Bonapartea, which last can possibly be admitted only in honour of the Empress, and not of her consort, who has no botanical pretensions. Our own beloved HONOUR OF BOTANISTS. £31 sovereign could derive no glory from the Georgia* of Ehrhart ; but the Strelitzia of Aiton stands on the sure basis of botanical knowledge and zeal, to which I can bear ample and very disinterested testimony. Linnaeus, in his entertaining book Critica Botanica, p. 79, has in several instances drawn a fanciful analogy between botanists and their appropriate plants, thus— Bauhinia, after the two distinguished brothers John and Caspar Bauhin, has a twolobed or twin leaf, Scheuchzeria, a grassy alpine plant, commemorates the two Scheuchzers, one of whom excelled in the knowledge of alpine productions, the other in that of grasses. Dorstenia, with its obsolete flowers devoid of all beau- ty, alludes to the antiquated and uncouth book of Dors- tenius. Hernandia, an American plant, the most beautiful of all trees in its foliage, but furnished with trifling blos- soms, bears the name of a botanist highly favoured by fortune, and allowed an ample salary for the purpose of investigating the natural history of the Western world, but whose labours have not answered the expense. On the contrary Magnolia with its noble leaves and flowers, and Dillenia with its beautiful blossoms and fruit, serve to immortalize two of the most meritorious among bot- anists. Linnaa, " a depressed, abject, Lapland plant, Long overlooked, flowering at an early age, was named by Gronovius after its prototype Linnaeus." * Tetrafthis of Hedwig and Engl. Bat. t. 1020. £92 REMARKS ON In pursuance of the same idea Dicksoma, a beautiful and curious fern, is well devoted to our great cryptoga- mist; Knappia, a small and singular grass, to an author celebrated for his minute and curious drawings of that tribe ; Sprengelia, to one distinguished for illustrating the impregnation of plants, which the remarkable form ahd union of its anthers serve to indicate ; while Smithia sensitiva, named by Mr. Dryander* in the Hortus Kew- ensis of our mutual friend Aiton, could at that time be merited only by an original treatise on the Irritability of Plantsf, to which the specific name happily alludes. The generic name being fixed, the specific one is next to be considered. With respect to this, Rivinus has the merit of originality, having been the first to contrive naming each plant in two words. But his names were meant for specific definitions, for which they are totally inadequate. Linnaeus, in constructing his more accu- rate and full specific characters, intended the latter should serve as names, and therefore called them nomina speciHca. When he, most fortunately for the science and for the popularity of his whole System of Nature, invented the present simple specific names, he called them nomina trivialia, trivial, or for common use ; but; that term is now superfluous. Specific names should be formed on similar princi- ples to the generic ones ; but some exceptions are al- lowed, not only without inconvenience, but with great advantage. Such as express the essential specific char- acter are unexceptionable, as Banksia serrata, integrifo^ * Salisb. Hort. 342, f Phil. Trans, for 1788. SPECIFIC NAMES'. 2® Ha, dentata, &c. ; but perhaps those which express something equally certain, but not comprehended in that character, are still more useful, as conveying addi- tional information, like Ixora alba and coccinea, Scle- ranthus annuus and perennis, Aletris fragrans, Saxifraga cernua, &c. ; for which reason it is often useful that vernacular names should not be mere translations of the Latin ones. Comparative appellations are very good, as Banksia ericifolia, Andromeda salicifolia*, Saxifraga bryoides, Milium cimicinum, Elymus Hystrix, Pedicula- ris Sceptrum.( 117) Names which express the local situa- tions of different species are excellent,such as Melampyrum * Some botanists write eriaefolia, salicisfolia, linguaformis, &c, instead of following the analogy of the Latin in forming adjectives with an i, as fialmifer from fialma, a ; baccifer, from bacca, a ,• barbiger, from barba, ** PENTANDRIA. observes, by the habit of a Thistle. Lagoecia is justly referred to this natural order by the same writer, though it has only a solitary seed and style. The Umbellifera are mostly herbaceous ; the qual- ities of such as grow on dry ground are aromatic, while the aquatic species are among the most deadly of poisons ; according to the remark of Linnaeus, who detected the cause of a dreadful disorder among horned cattle in Lapland, in their eating young leaves of Cicuta virosa, Engl. Bot. t. 479, under water. (127) Botanists in general shrink from the study of the Umbellifera, nor have these plants much beauty in the eyes of amateurs ; but they will repay the trouble of a careful observation. The late M. Cusson of Montpellier bestowed more pains upon them- than any other botanist has ever done ; but the world has, as yet, been favoured with only a part of his remarks. His labours met with a most ungrateful check, in the unkindness, and still more mortifying stupidity, of his wife, who, on his absence from home, is recorded to have destroyed his whole herbarium, scraping off the dried specimens, for the sake of the paper on which they were pasted! 3. Trigynia is illustrated by the Elder, the Sumach, or Rhus, Viburnum, &c, (128) also Corrigiola, Engl. (127) [To this general rule there are exceptions. The pois- onous Hemlock, Conium maculatum, grows in dry ground, while several species of Angelica,vfh\ch are aromatic and harmless,inhab- it watery places.] (128) [The Sumach, Rhus ; Elder, Sambucus, and many simi- lar shrubs with pithy stems and small flowers, constitute the Lin- naean order Dumosoe^\ HEXANDRIA. 398 Bot. t. 669, and Tamarix, t. 1318, of which last one species, germanica, has 10 stamens. 4. Tetragynia has only Evolvulus, nearly allied to Con- volvulus, and the elegant and curious Parnassia, t. 82. 5. Pentagynia contains Stat'we, t. 226, 102, and 328, a beautiful maritime genus, with a kind of everlasting calix. The Flora Graca has many fine species. Linum or Flax follows : also the curious exotic Aldro- vanda, Dicks. Dr. PI. 30 ; Drosera, Engl. Bot. t. 867 —9 : the numerous succulent genus Crassula ; and the alpine Sibbaldia, t. 897, of the natural order of Rosacea. 6. Polygynia. Myosurus, t. 435, a remarkable instance of few stamens (though they often exceed five) to a multitude of pistils. Class 6. Hexandria. Stamens 6. Orders 6. 1. Monogynia. This, as usual, is the most numerous. The Liliaceous family,with or without a spatha, (129) called by Linnaeus the nobles of the vegetable king- dom, constitute its most splendid ornament. The beautiful White Lily is commonly chosen by popular writers to exemplify the stamens and pistils. The less ostentatious genus oiJuncusorRu&x,which soon follows is more nearly allied to the Lilies than a young bota- nist would suppose. Near it stand several genera which have little affinity to each other, and of these Capura is a mistake, having been made out of a (129) [Called by Linnaeus Sftathaceoe and Coronarix, according as the spathe is present or wanting.] ;i2* HHPTANDR1A. specimen of Daphne indica, which chanced to have but six stamens. % Digynia, has but few genera. The valuable Oryza, Rice, of which there now seems to be more than one species, is the most remarkable. It is a grass with six stamens. 3, Trigynia. See Rumex, Engl. Bot. t. 1533,127, &c, some species of which have separated flowers ; Tqfi-, eldia, t. 536 ; and Colchicum, t. 133 and 1432. 4. Tetragynia. Petiveria alliacea, a plant the number of whose stamens is not very constant, and whose specific name is supposed to allude, not only to its garlic scent, but also to the caustic humour of the bo- tanist whom it commemorates. 5. Hexagynia. An order in Schreber and Willdenow, contains Wendlandia populifolia of the latter ; with Damasonium of the former, a genus consisting of the Linnaean Stratiotes alismoides, Exot. Bot. t. 15. 6. Polygynia, Alisma only—Engl. Bot. t. 837, 775, &c. Class 7. Heptandria. Stamens 7. Orders 4. 1. Monogynia. Trientalis, Engl. Bot. t. 15, a favour- ite plant of Linnaeus; and ALsculus, the Horse Ches- 'nut. Several genera are removed to this order by late writers. %. Digynia. Limeum, an African genus, only. 3. Tetragynia. Saururus, a Virginian plant. Aponog- eton, placed here by Linnaeus, is now properly re OCTANDRIA. 32i> moved to Dodecandria. It is an East Indian and Cape aquatic genus, bearing above the water white fragrant flowers in a peculiar spike, which is either solitary or double. 4. Heptagynia. Septas, a Cape plant, very nearly akin to Crassula, to which Thunberg refers it. If its char- acter in Linnaeus be constant with respect to number, it is very remarkable, having the calyx in 7 deep seg- ments, 7 petals, 7 germens, and consequently 7 cap- sules. Class 8. Oetandria. Stamens 8. Orders 4. 1. Monogynia. A very various and rich order, consist- ing of the well-known Tropaolum or Nasturtium, whose original Latin name, given from the flavour of the plant, like Garden Cresses, is now become its English one in every body's mouth. The elegant and fanciful Linnaean appellation, equivalent to a tro- phy plant, alludes to its use for decorating bowers, and the resemblance of its peltate leaves to shields, as well as of its flowers to golden helmets, pierced through, and through, and stained with blood. See Linn. Hort. Cliff. U3.—Epilobium, Engl. Bot. U 838, 795, &c, with its allies, makes a beautiful part of this order ; (130) but above all are conspicuous the favourite Fuchsia, the chiefly American genus Vac- (130) [The natural order Calycanthemct,includes many beautiful American plants of this class. Such are Eftilobium, Gaura amothera, Rhexia, &c. These have their petals and stamens in- ,m-ted in the calvx, which commmonly stands upon the germ.] 326 EN NE AN DMA. oinium, t. 456, 319, &c.; the immense and most ele- gant genus, Erica, so abundant in southern Africa, but not known in America ; and the fragrant Daphne, t. 1381, of which last the Levant possesses many charming species. Acer, the Maple, is removed hith- er in Fl. Brit, from the 23d class. 2. Digynia has a few plants, but little known; among them are Galenia africana, and Moehringia mus- cosa. 3. Trigynia. Polygonum, t. 436, 509, 941, is a genus whose species differ in the number of their stamens and styles, and yet none can be more natural. Here therefore the Linnaean system claims our indulgence. Paullinia and Cardiospermum are more constant. 4. Tetragynia. Here we find the curious Paris, t. 7, and Adoxa, t. 453. Of the former I have lately re- ceived a new species, gathered by my liberal friend Buchanan among the mountains of Nepal. Class 9. Enneandria. Stamens 9. Orders 3. 1. Monogynia. Qi this the precious genus Laurus, in- cluding the Cinnamon, Bay, Sassafras, Camphor, and many other noble plants, is an example. 2. Trigynia has only Rheum, the Rhubarb, nearly re- lated to Rumex. 3. Hexagynia. Butomus umbellatus, Engl. Bot. t. 651, a great ornament to our rivers and pools. DECANDRlA. 32f Class 10. Decandriq. Stamens 10. Orders 5. 1. Monogynia. A numerous and fine assemblage, be- ginning with a tribe of flowers more or less correctly papilionaceous and leguminous, which differ very materially from the rest of that natural order in having ten stout, firm, separate stamens. See Cassia, Curt. Mag. t. 107, 633, and Sophora, t. 167; also Exot. Bot. t. 25—27, and Annals of Botany, v. 1. 501. The Ruta, Rue, and its allies, now become very numerous, follow. See Tracts on Nat. Hist. 287. Dictumnus, vulgarly called Fraxinella, is one of them. Dionaa Muscipula, seep. 146, stands in this artificial order, as do the beautiful Kalmia, Rhododendron, An- dromeda, Arbutus and Pyrola, Engl. Bot. t. 213, &c. (131) 2. Digynia. Saxifraga, remarkable for having the german inferior, half inferior, and superior, in differ- ent species, a very rare example. See Engl. Bot. t. 167, 440, 663, 1009, 500, 501. Dianthus, the Pink or Carnation tribe, and some of its very distinct nat- ural order, Caryophyllea, conclude the Decandria, Digynia. (132) 3. Trigynia. The Caryophyllea are here continued, as Cucubalus, t. 1527, Silene, t. 465, 1398, Arenaria, t. 189, 512, very prolific and intricate genera in the Le- (131) [The last genera, with Erica and Vaccinium, from Ihe 8th class, and some others, constitute the natural order Bi- eornes, so called, because their anthers are furnished with two long straight points or horns.] (132) [The Caryofthyllea have five petals inserted with claws. Cucubalus, Arenaria, Stellaria, Etc. are native genera of this order.] '12& DODECANDRIA vant. Malpighia and Banisteria, beautiful plants of the Maple family, which next occur, have no affinity to the foregoing. 4. Pentagynia. Abounds in more Caryophyllea, as Lychnis, t. 573, and Cerastium. t. 789, 790. Coty- ledon, 325, Sedum, t. 1319,, and Oxalis, t. 762, are placed here. Some of the last genus have the fila- ments united at their base, and therefore should be- long to the 16th class,—another defect in the artificial system. 5. Decagynia. Consists of only Neurada, with Phyto- lacca ; the latter an irregular genus as to stamens and styles, which therefore afford good marks to discrim- inate the species. Class 11. Dodecandria. Stamens 12 to 19. Orders 6. 1. Monogynia. A rather numerous and very various order, with scarcely any natural affinity between the genera. Some of them have twelve, others fifteen or more stamens, which should be mentioned in their characters. Asarum, Engl. Bot. t. 1083, and the handsome Lythrum Salicaria, t. 1061, also the Amer- ican Snow-drop-tree, Halesia, not rare in our gardens, may serve as examples of this order. Sterculia is very properly removed hither from Gynandria by Schreber and Willdenow, as its stamens are not in- serted above the germen. 2. Digynia consists of Heliocarpus, a very rare Ameri can tree with a singularly fringed or radiated fruit; ICOSANDRIA. 329 and Agrimonia, Engl. Bot. t. 1335. The latter might as well have been placed in the next class, with which it agrees in natural order. 3. Trigynia is chiefly occupied by Reseda, the Migno- nette, t. S20, 321, and Euphorbia, t. 256, 883, &c, one of the most well defined and natural genera, of which the Punicea, Ic. Pict. t. 3, is a splendid ex- otic species. 4. Tetragynia, in Schreber and Willdenow, consists of Calligonum, a genus illustrated by L'Heritier in the Transactions of Linn. Society, v. 1; and Aponogeton, already mentioned p. 324. 5. Pentagynia has Glinus, an insignificant genus ; and Blackwellia, a doubtful one. 6. Dodecagynia is exemplified in Sempervivum, the Houseleek, Engl. Bot. t. 1320, whose styles vary from 12 to 18 or 20. Sempervivum Sediforme,Jacq. Hort. Vind. t. 81, is a Sedum with a superabundance of parts in the fructification. Linnaeus confounded it with S. rupestre. Class 12. Icosandria. Stamens 20 or more, inserted into the Calyx. Orders 3. 1. Monogynia consists of fine trees, bearing for the most part stone fruits, as the Peach, Plum, Cherry, &c, though the leaves and other parts are bitter, acrid, and, as we have already mentioned, sometimes very dan- gerous, owing to the peculiar essential oil, known by ss ■o# (COS ANURIA. its bitter-almond flavour. See specimens of this fam- ily in Engl. Bot. t. 1383, 706, 841, 842. The Myr- tle tribe (133) is another natural order, comprehended chiefly under Icosandria Monogynia, abounding in a fragrant and wholesome aromatic oil. These are plen- tiful in New Holland. See Tr. of Linn. Soc. v. 3. 255, also Exot. Bot. t. 43, 59, and 84. Caryophyllus aromaticus, the Clove, should on every account be removed hither. 2. Pentagynia. In this order it is most convenient to include such plants as have from two to five styles, and occasionally, from accidental luxuriance only, one or two more. An example of it is the very natu- ral family of the Pomacea, as Pyrus, the Apple, Pear, &c. Engl. Bot. t. 179, 350, 337 ; and Mespilus, t. 1523, Exot. Bot. t. 18, 85. In this family some species of the same genus have five, others three, two, or only one style, and a corresponding number of seeds. Spiraa, nearly allied to it, stands here, most of its species having five styles, though some have a much greater number ; see Engl. Bot., t. 284, 960. Mesembryanthemum, a vast and brilliant exotic genus, of a succulent habit, abounding in alkaline salt, and a few genera naturally allied to it, make up the rest of the order. 3. Polygynia. An entirely natural order of genuine Rosaceous flowers, except possibly Calycanthus. (133) \Hesfteride& of Linnaeus. They have firm, evergreen teaves, sweet scented flowers, and numerous stamens.] ICOSANDRlA. o31 Here we find Rosa, Engl. Bot. t. 187, 990—2 ; Ru- bus, t. 826, 827, 716; Fmgaria, t. 1524 ; Potentil- la, t. 88, 89, 862 ; Tormentilla, t. 863, 864 ; Geum, t.l06\ Dryas, t. 451; and Comarum, t. 172: all elegant plants, agreeing in the astringent qualities of their roots, bark and foliage, and in their generally eatable, always innocent, fruit. (134) The vegetable kingdom does not afford a more satisfactory example of a natural order, composed of natural genera, than this ; and Linnaeus has well illustrated it in the Flora Lapponica. His genus Tormentilla, differing from Potentilla in number of petals and segments of the calyx, though retained by Jussieu, may perhaps be scarcely distinct; yet there is a difference in their habit, which has induced me to leave it for further consideration. Haller united them both with Fraga- ria and Comarum, which the character and habit of the latter totally forbid, and Gaertner has well sug- gested a mark from the smoothness of the seeds in Fragaria, (as well as Comarum,) to strengthen that of its pulpy receptacle. Whatever difficulties may at- tend these genera, how admirably does the fruit serve us in Rosa, Rubus, Dryas and Geum, to discriminate those whose leaves, flowers, and habit all stamp them as distinct ! A student cannot do better than to study this order and these genera, as an introduction to the knowledge of more obscure ones ; and the beautiful plants which compose it, mostly familiar to every body, are easily obtained. (134) [The Rose, Bramble, Strawberry, Cinquefoil, and the other plants mentioned above were called by Linnaeus Senticosai] JJ2 POLYANDRIA. Class 13. Polyandria. Stamens numerous, inserted into the Receptacle. Orders 7. 1. Monogynia. The genera of this order are artificially distributed according to the number of their petals, but not so arranged in the body of the system. They form a numerous and various assemblage of handsome plants, but many are ofa suspected quality. Among them are the Poppy, the Caper-shrub, the Sanguina- ria canadensis, Curt. Mag. t. 162, remarkable for its oiange juice, like our Celandine, Engl. Bot. t. 1581 ; (135) also the beautiful genus Cistus with its copious but short-lived flowers, some of which (Engl. Bot. t. 1321) hive irritable stamens ; the splendid aquatic tribe of Nymphaa, &c, t. 159, 160. But the pre- cious Nutmeg and the Tea are perhaps erroneously placed here by Linnaeus, as well as the Clove ; while on the other hand Cleome more properly belongs to this part of the system than to the 15th Class. 2. Digynia has principally the Paonia, t. 1513, variable in number of pistils, and Fqthergilla alnifolia, an American shrub, 3. Trigynia. Delphinium the Larkspur, and Aconitum the Monk's hood, two variable and uncertain genera as to number of pistils, (135) [The Poppy, Celandine, Blood Root, 8cc. which have a capsule or silique, and a caducous calyx belong to the natural order Rhceadete. Some other genera chiefly of the order Polygy- nia, which have many pods, or many naked seeds, to one flower, are placed in the natural order Multisiliquce. Such are Caltha, Aquilegia, Anemone, Ranunculus, $tc] POLYANDRIA. 333 4. Tetragynia. Tetracera ought, by its name, to have constantly four pistils, but the rest of this order are very doubtful. Caryocar, whose large rugged woody nuts contain the most exquisite kernel ever brought to our tables, and which is the same plant with Gaert- ner's and Schreber's Rhizobolus, as the excellent Willdenow rightly judged, is not certain in number ; and still less the Cimicifuga ; whilst Wahlbomia is probably a Tetracera : see Willdenow, 5. Pentagynia contains chiefly Aquilegia the Colum- bine, and Nigella—both strictly allied to genera in the third order. Reaumuria indeed is here well pla- ced. Some Nigella have ten styles. 6. Hexagynia consists of Stratiotes, Engl Bot. t. 379 ; and Brasenia, a new genus of Schreber's with which I am not acquainted. (136) I would recommend an union of the last five orders, for the same reasons that influenced me in the preced- ing class. They now only serve to keep natural gen- era asunder, the species of which not only differ among themselves as to number of pistils, but each species is often variable besides. The genera are so few that no inconvenience could arise on that account. I conceive such reforms, founded in experience not in theory, serve to strengthen the system, by greatly facilitating its application to practice. (136) [I presume it is the Hydrofteltis of Michaux, the onh species of which is a common North American aquatic ; both from the similarity of their characters, and the application of the iiame in Da. Muhlenburg's catalogue. Ed.~] 334 DIDYNAMIA. 7. Polygynia. An order for the most part natural, com- prehending some fine exotic trees, as Dillenia, Exot. Bot. t. 2, 3, 92 and 93 ; Liriodendron, the Tulip- tree ; the noble Magnolia, &c. ; a tribe concerning whose genera our periodical writers are falling into great mistakes. To, these succeed a family of plants, either herbaceous ©^climbing, of great elegance, but of acrid and dangerous qualities, as Anemone, in a single state the most lovely, in a double one the most splendid, ornament of our parterres in the spring ; Atragena and Clematis, so graceful for bowers; Tha- lictrum, Adonis, Ranunculus, Trollius, Helleborus and Caltha, all conspicuous in our gardens or meadows, which, with a few less familiar, close this class. Nothing can be more injudicious than uniting these two last classes, as some inexperienced authors have done. They are immutably distinct in nature and characters, whether we call the part which immedi- ately bears the stamens in the Icosandria a calyx, with most botanists, or a receptacle with Mr. Salisbury in the 8th vol. of the Linnaean Society's Transactions, where, among many things which I wish had been omitted^ are some good remarks concerning the dis- tinction made between calyx and corolla. This the writer in question considers as • decided in doubtful cases by the latter sometimes bearing the stamens, which the former, in his opinion, never really does. Class 14. Didynamia. Stamens 2 long and 2 short. Orders 2, each on the'whole very natural. 1. Gymnospermia. Seeds naked, in the bottom of the calyx, 4, except in Phryma, which has a solitary DYDINAMIA. 335 seed.—Corolla monopetalous and irregular, a little inflated at the base, and holding honey, without any particular nectary. Stamens in 2 pairs, incurved, with the style between them, so that the impregnation rarely fails.(137) The plants of this order are mostly aromatic, and none, I believe, poisonous. The calyx is either in 5 nearly equal*segments, or 2 lipped. Most of the genera afford excellent essential charac- ters, taken frequently from the corolla, or from some other part. Thus, Perilla has 2 styles, of which it is.an unique example in this class. Mentha a corolla whose segments are nearly equal, and spreading stamens. Engl. Bot. t. 446—8. Lavandula the Lavender and Westringia, Tracts on Natural History, 277, t. 3, have a corolla resupinata, reversed or laid on its back. Teucrium a deeply divided upper lip, allowing the stamens and style to project between its lobes. Engl. Bot. t. 680. Ajuga scarcely any upper lip at all, t. 77 and 489. Lamium has the mouth toothed on each side, t. 768. Prunella, t. 961, has forked filaments ; Cleonia 4 stigmas ; Prasium a pulpy coat to its seeds. These (137) [Plants of this order, besides their 4 unequal stamens, rin- gent corolla and naked seeds ; have their flowers commonly- arranged in whorls, their stems square and their leaves opposite. Examples are common, as, the Mints, Germander, Balm, Catmint, Ground Ivy, 8cc. They form the natural order Verticillatx of Linnaeus, and Labiatte of Jussieu. Some of the genera however depart from the usual mode of inflorescence, as Trichostema and others.] 336 TETRADYNAMIA. - instances will suffice as clear examples of natural gen- era, distinguished by an essential technical character, in a most natural order. 2. Angiospermia. Seeds in a capsule, and generally very numerous. (138)—The plants of this order have the greatest possible affinity with some families in Pentandria Monogynia. (139) Some species even vary from one class to the other, as Bignonia radicans, Curt. Mag. t. 485, and Antirrhinum Linaria, Engl. Bot. t. 658, 260, in which the irregular corolla be- comes regular, and the 4 unequal stamens are chang- ed to 5 equal ones ; nor does this depend, as has been asserted, on the action of any extraneous pollen upon the stigmas of the parent plant, neither are the seeds always abortive. No method of arrangement, natural or artificial, could provide against such anom- alies as these, and therefore imperfections must be ex- pected in every system. Class 15. Tetradynamia. Stamens 4 long and 2 short. Orders 2, perfectly natural. Flowers cruci- form. 1. Siliculosa. Fruit a roundish pod, or pouch. In some genera it is entire, as Draba, Engl. Bot. t. 586, and the Honesty or Satin flower Lunaria: in others (138) [The Perxonatce or masked flowers are chiefly found here, as Antirrhinum, Chelone, Mimulus, 8cc] (139) [Some genera of this order have the rudiment of a fifth stamen ; as Chelone, Pentstemon, 8cc. while many plants of the fifth class have an irregular monopetalous corolla, resembling those of this order.] TETRADYNAMIA, 337 notched, as Thlaspi, t. 1659, and Iberis, t. 52 ; which last genus is unique in its natural order in having un- equal petals. Crambe, t. 924 ; Isatis. t. 97 ; and Bunias, t. 231 ; certainly belong to this Order, though placed by Linnaeus in the next. 2. Siliquosa. Fruit a very long pod. Some genera have a calyx clausus, its leaves slightly cohering by their sides, as Raphanus, t. 856 ; Cheiranthus, t. 462 ; Hesperis, t.73l; Brassica, t. 637, &c. Others have a spreading or gaping calyx, as Cardamine, t. 1000 ; Sisymbrium, t. 855 ; and especially Sinapis, t. 969 and t. 1677. Cleome is a very irregular genus, allied in habit, and even in the number of stamens of several species, to the Polyandria Monogynia. Its fruit, moreover, is a capsule of one cell, not the real two-celled pod of this Order. Most of its species are foetid and very poisonous, whereas scarcely any plants properly be- longing to this Class are remarkably noxious, for I have great doubts concerning the disease called Ra- phania, attributed by Linnaeus to the seeds of Ra- phanus Raphanistrum. The Cruciform plants are vulgarly called antiscor- butic, and supposed to be of an alkalescent nature. Their essential oil, which is generally obtainable in very small qualities by distillation, smells like volatile alkali, and is of a very acrid quality. Hence the foetid scent of water in which cabbages, or other plants of this tribe, have been boiled. TT 338 MONADELPHIA. Class' 16. Monadelphia. Stamens united by their filaments into one tube. Orders 8, distinguished by the number of their stamens. 1. Triandria is exemplified by Sisyrinchium, Ic. Pict. t. 9, and Ferraria, Curt. Mag. t. 144, 532, both erro- neously placed by Linnaeus in Gynandria. Also the singular Cape plant Aphyteia, consisting of a large flower and succulent fruit, springing immediately from the root, without stem or leaves. On this plant Linnasus published a dissertation in 1775. Tama- rindus has lately been removed hither from the third Class, perhaps justly. 2. Pentandria. Erodium, Engl. Bot. t. 902, separated, with great propriety, from Geranium by L'Heritier ; Hermannia, a pretty Cape genus, Curt. Mag. t. 307 ; and a few other plants, more or less akin to the Mal- low tribe, compose this Order ; to which also strictly belong some species of Linum, Geranium, &c. Pas- sifiora, removed from Gynandria, belongs most un- questionably to Pentandria Trigynia, and by no means to this Class. 3. Heptandria consists only of Pelargonium of L'Heri- tier, an excellent genus, comprising most of the Cape Geraniums, and marked by its irregular flower, 7 stamens, and tubular nectary. , 4. Octandria contains Aitonia, Curt. Mag. t. 173, nam- ed in honour of the excellent and universally respected author of the Hortus Kewensis. Pistia is, I believe justly, placed here by Schreber and Willdenow. MONADELPHIA. 335 5. Decandria. Geranium, properly so called, Engl. Bot. t. 404, 405, 272, &c, is the principal genus here. The late Professor Cavanilles, however, in his Dissertationes Botanica referred to this order a vast number of genera, never before suspected to be- long to it, as Bannisteria, Malpighia, Turraa, Melia, &c, on account of some fancied union of their fila- ments, perhaps through the medium of a tubular nec- tary ; which principle is absolutely inadmissible ; for we might just as well refer to Monadelphia every plant whose filaments are connected by insertion into a tubular corolla. Some species of Oxalis, see p. 327, belong to this Order ; as do several papiliona- ceous genera, of which we shall speak under the next class. (140) 6. Endecandria contains only the splendid South-Amer- ican genus Brownea, the number of whose stamens is different in different species. 7. Dodecandria, Stamens mostly 15, is composed of some fine plants allied to the Mallows, as Pterosper- mum, t. 620, Pentapetes, &c. 8. Polyandria, a very numerous and magnificent Order, comprises, among other things, the true Columnife- ra or Malvacea, (141) as Malva, Engl. Bot. t. 671, 754, Althaa, t. 147, Hibiscus, Spied. Bot. t. 8, Gos- (140) [The Geraniums, Oxalis, and some others, which have a five petalled corolla, and their fruit surmounted with a beak, are called by Linnaeus Gruinales.~] (141) [The Malvaceous plants were called by Linnaeus Colum- nifera, on account of the large tube of stamens, rising like a col- umn in the centre of the flower.] 340 DIADELPHIA. sypium, the cotton-tree, Alcea the Hollyhock, &c. Stately and beautiful plants of this Order, though not Malvacea, are Carolinea, whose angular seeds are sold in our shops by the name of Brasil nuts ; Gusta* via, named after the late King of Sweden, a great pat- ron of botany and of Linnaeus ; Camellia, Curt. Mag. t. 42, whose splendid varieties have of late become favourites with collectors ; Stuartia, Exot. Bot. t. 110 ; and Barringtonia, the original Commersonia, Sonnerat Voy. a la Nouv. Guinee, t. 8, 9. Class 17. Diadelphia. Stamens united by their fila- ments into 2 parcels, both sometimes cohering at the base. Orders 4, distinguished by the number of their Stamens,—Flowers almost universally papiliona- ceous, 1. Pentandria. The only genus in this Order is Mon- nieria, Lamarck, t. 596, .a rare little South American plant, vvhose natural order is uncertain. It has a rin- gent corolla, ternate leaves, a simple bristly pubes- cence, and is besprinkled with resinous dots. 2, Hexandria. Sqraca, in this Order, is as little known as the Monnieria, except that it undoubtedly belongs to the leguminous family. It seems most alli- ed to Brownea, Jonesia,9Afzelia, &c. Fumaria, the only genus besides, is remarkable for the great varie- ty of forms in its seed-vessel, whence botanists who make genera from technical characters, without regard to natural principles, have injudiciously subdivided it, See Engl. Bot. t. 588—590, 943, 1471. DIADELPHIA. 341 3. Obtandria. Polygala, t. 76, is the principal genus here. America and the Cape of Good Hope abound in beautiful species of it, and New Holland affords some new genera, long confounded with this. Dal- bergia is perhaps as well placed in the next Order. 4. Decandria is by far the most numerous, as well as natural, Order of this Class, consequently the genera are difficult to characterize. They compose the fam- ily of proper Papilionaca or Leguminosoz, the Pea, Vetch, Broom, &c.' Their stamens are most usually 9 in one set, with a single one separate^ The genera are arranged in sections variously charac- terized. * Stamens all united, that is, all in one set. The plants of this section are really not diadelphous but mo- nadelphous. See Spartium, Engl. Bot. t. 1339. Some of them, as Lupinus, and Ulex, t. 742, 743, have in- deed the tenth stamen evidently distinguished from the rest, though incorporated with them by its lower part. Others have a longitudinal slit in the upper side of the tube, or the latter easily separates there, as Ononis, t. 682, without any indication of a separate stamen. Here therefore the Linnaean System swerves from its strict artificial laws, in compliance with the decisive natural character which marks the plants in question. Wre ea- sily perceive that character, and have only to ascertain whether any papilionaceous plant we may have to ex- amine has 10 stamens, all alike separate and distinct, in which case it belongs to the 10th Class, or whether they are in any way combined, which refers it to the 17lh. 342 DlADELPHIA ** Stigma downy, without the character of the pre- ceding section, for this and all the following are truly di- adelphous. Very nice, but accurate, marks distinguish the genera, which are sufficiently natural. The style and stigma afford the discriminative characteristics of Orobus, t. 1153 ; Pisum, t. 1046 ; Lathyrus, t. 670, 1108 ; Vicia, t. 334, 481—483 ; and no less decisively in Ervum, t. 970, 1223, which last genus, notwithstand- ing the remark in Jussieu 360, " stigma non barbatum," (taken probably from no genuine species,) most evi- dently belongs to this section, as was first remarked in the Flora Britannica ; and it is clearly distinguished from all the other genera of the section by the capitate stigma hairy all over ; nor is any genus in the whole Class more natural, when the hitherto mistaken species are removed to their proper places. See Fl. Brit. *** Legume imperfectly divided into two cells, al- ways, as in all the following, without the character of the preceding sections. This is composed of the singular Biserrula, known by its doubly serrated fruit, of which there is only one species ; the Phaca, Jacq. Ic. Rar. t. 151 ; and the vast genus of Astragalus, Engl. Bot. t. 274, &c, lately illustrated in a splendid work by an able French botanist, Decandolle. **** Legume with scarcely more than one seed. Of this Psoralea, Curt. Mag. t. 665; the curious Stylosan- thes of Swartz ; the Hallia of Thunberg ; and our own Trifolium, Engl. Bot. t. 1770, 1048—1050, are exam- ples. The last genus, one of the most natural as to DlADELPHIA. 34 j habit and qualities, is extremely untractable with re- spect to botanical characters. Some species, t. 1047, 1340, 1769, have many seeds in each pod ; some have not even the capitate inflorescence made a part of the generic definition. The difficulty is lessened by estab- lishing Melilotus as a genus, with Jussieu : but the whole requires to be well reconsidered ; for, if possible, so great a laxity of definition, with such glaring excep- tions, should not disgrace any system. ***** Legume composed of single-valved joints, which are rarely solitary. Hedysarum, t. 96, is the most important genus of this section, and is known by its obtuse or rectangular keel. Hippocrepis, t. 31 ; Ornithopus, t. 369 ; and Scorpiurus, known in gardens by the name of Caterpillar, from its worm-like pod, are further examples. Smithia, Ait. Hort. Kew. t. 13, is remarkable for having the joints of the legume connect- ed by means of the style, as by a thread ; the stamens in 2 equal divisions, with 5 anthers to each ; and a two- lipped calyx. Hedysarum vespertilionis, Jacq. Ic. Rar. t. 566, in some points approaches this genus, and more certain species are possibly latent among the numerous unsettled papilionaceous plants of India. ****** Legume of one cell, with several seeds. To this belong the genus Meliotus, if separated from Trifo- lium ; the Indigofera, several species of which are so valuable for dyeing blue ; the handsome Robinia, Curt. Mag. t. 311 ; Cytisius,t. 176, &c. ; and Clitora*, Ins. * From Knite, to close or shut up, in allusion to the situation of the wings and keel. v 344 POLYADELPHIA. of Georgia, t. 18 : also Lotus, Engl. Bot. t. 925, and Medicago, t. 1616 ; which last is justly transferred by Willdenow from the foregoing section to this. Papilionaceous plants are rarely noxious to the larger tribes of animals, though some species of Galega intoxi- cate fish. The seeds of Cytisus Laburnum have of late been found violently emetic, and those of Lathyrus sati- vus have been supposed at Florence to soften the bones, and cause death ; we know of no other similar instan- ces in this Class, which is one of the most abundant in valuable esculent plants. The negroes have a notion that beautiful little scarlet and black seeds of Abrus pre- catorius, so frequently used for necklaces, are extremely poisonous, insomuch that half of one is sufficient to kill a man. This is totally incredible. Linnaeus however as- serts rather too absolutely, that" " among all the legum- inous or papilionaceous tribe there is no deleterious plant to be found." Class.18. Polyadelphia. Stamens united by their filaments into more than 2 parcels. Orders 3, dis- tinguished by the number or insertion of their stamens. which last particular Linnaeus here overlooked. No part of the Linnfean system has been less accu- rately defined or understood than the Orders of the 18th Class. Willdenow, aware of this, has made some improvements, but they appear to me not suffi- cient, and I venture to propose the following arrange- ment. 1. Dodecandria. Stamens, or rather Anthers, from 12 to 20, or 25, their filaments unconnected with the POLYADELPHIA. 145 calyx. Of this the first example that presents itself is Theobroma, the Chocolate tree, Merian. Sarin, t. 26, 63, Lamarck Encycl. t. 635. The flowers have not been seen fresh in Europe, and we only know them from drawings made in the West Indies, one of which, preserved in the Linnaean herbarium, is my authority for the following descriptions. The fila- ments are inserted between the long tapering segments of a 5-cleft nectary, on its outside, and each bears at Its summit 4 sessile,, obtuse, spreading anthers. Aublet's figure of this genus, which Schreber and Willdenow seem to have followed, represents but 2. The fruit is perhaps most properly a berry with a hard coat, whose seeds, when roasted, make choco- late. Bubroma of Schreber, Guazuma Lamarck, t. 637, confounded by Linnaeus with the preceding ge- nus, has similar filaments, but each bears 5 anthers ; Jussieu and Cavanilles say 3. The fruit is a woody capsule, with 10 rows of perforations. Abroma, Jacq. Hort. Vind. v. 3. t. 1. Miller Illustr. t. 63, has 5 par- cels of anthers, nearly sessile on the outside of the nectary, between its obtuse, reflexed, notched lobes. It is difficult to say how many anthers compose each parcel, for the different accounts on record are totally irreconcileable. We have found 3 ; the drawing sent to Linnaeus represents 6 ; and Miller has a much greater number. Perhaps they may vary. In this uncertainty the genus in question is best placed with its natural allies in this order, wifh a reference to it in italics at the end of Polyadelphia Polyandria. Its UTT ,46 POLYADELPHIA. fruit is a membranous winged capsule, opening at the top. Monsonia, Curt. Mag. t. 73, Lamarck, t. 638, removed by Schreber and Willdenow to Monadel- phia, rather, I think, belongs to this class where Lin- naeus placed it. The 5 filaments, bearing each 3 long-stalked anthers, are merely inserted into a short membranous cup, or nectary, for so the analogy of the 3 preceding genera induces us to call it ; and if we refer Monsonia to Monadelphia, we fall into the error of Cavanilles mentioned p. 339. Lastly, Citrus, the Orange, Lemon, Sec, Lamarck, t. 639, most unques- tionably belongs to this Order. Its stamens are about 19 or 20, combined variously and unequally in sev- eral distinct parcels ; but those parcels are inserted into a proper receptacle, by no means into the calyx, as the character of the Class Icosandria indispensably requires. Even the number of the anthers of Citrus accords better with most plants in Dodecandria than in Icosandria, notwithstanding the title of the latter. 2. Icosandria. Stamens numerous, their filaments inser- ted (in several parcels) into the calyx.—To this Order Professor Willdenow properly refers Melaleuca Exot. Bot. t. 34—36, 55, 56, which had previously stood in Polyandria, botanists having only considered num- ber and not insertion in the Orders of Polyadelphia, whence a double mistake has arisen, concerning Cit- rus on the one hand, and Melaleuca on the other. 3. Polyandria. Stamens very numerous, unconnected with the calyx. This Order consists of several gen- era. The most remarkable is Hypericum, Engl. Bot. SYNGENESIA 347 t. 109, 1225—1227, &c, whose stamens united into 3 or 5 parcels, corresponding with the number of its styles. Munchhausia is a Lagerstromia, nor does it appear to be polyadelphous at all. Linnaeus seems to have intended bringing Thea into this Order. Class 19. Syngenesia. Anthers united into a tube. Flowers compound. Orders 5. This being truly a "natural Class, its Orders are most of them equally so, though some are liable to exceptions, as will presently be explained. I. Polygamia aqualis. In this each floret, taken sep- arately, is perfect or united, being furnished with its own perfect stamens and pistil, and capable of bring. ing its seed to maturity without the assistance of any other floret. The Order consists of 3 sections. * Florets all ligulate, or strap-shaped, called by Tournefort Scmifiosculous. These flowers are gen- erally yellow, sometimes blue, very rarely reddish. They expand in a morning, and close towards noon or in cloudy weather. Their herbage is commonly milky and bitter. Leontodon, Engl. Bot. t. 510 ; Tragopogon, t. 434, 638 ; Hieracium, t. '349, &c; and Cichorium, t. 539, exemplify this very natural section. ** Flowers globose, generally uniform and regular, their florets all tubular, 5-cleft, and spreading. Car- duus, t. 107, 675, 973^976 ; Onopordum, t. 977 ; and Arctium, t. 1228, well exemplify this. Carli- 348 SYNGENESIA. na, t. 1144, does not so exactly agree with the above definition, having a flat disk ; but its affinity to the other genera is indubitable. Its flattened disk and radiating coloured calyx seem contrived to imitate the radiated flowers of the following Order. *** Flowers discoid, their florets all tubular, regu- lar',crowded and parallel, forming a surface nearly fiat, or exactly conical. Their colour is most generally yellow, in some cases, pink. Santolina, t. 141 ; and Bidens, t. 1113, 1114, are genuine examples of this section : Eupatorium, t. 428, and the exotic Staheli- na, Dicks. Dr. PI. 13, approach to the preceding one. There is however the most absolute difference between these two sections, collectively, and the first; while, on the other hand, they have considerable af- finity with some of the following Orders, as will be hereafter explained. 2. Polygamia superfiua. Florets of the disk perfect or united ; those of the margin furnished with pistils only j but all producing perfect seed. * Discoid, the florets of the margin being obsolete or inconspicuous, from the smallness or peculiar form of the corolla; as Artemisia, Engl. Bot. t. 338, 978, 1230; Tanacetum, t. 1229 ; Conyza, t. 1195 ; and Gnaphalium, t. 267, 1157. In the last the marginal florets are mostly 5-cleft and tubular like the rest, on- ly wanting stamens. Caution is requisite to detect the difference between this section and the preceding Order, SYNGENESIA. 3*19 ** Ligulate, 2-lipped, of which Perdicium, a rare exotic genus, is the only instance. *** Radiant, the marginal florets ligulate, form- ing spreading conspicuous rays ; as Bellis the Daisy, t. 424 ; Aster, t. 87, a very numerous genus in America; Chrysanthemum, t. 601, 540; Inula, t. 1546, &c. This section seems at first sight, a com- bination of the first and third sections of the former Order, but this is chiefly in the form of its corollas. It is rather an approach of that third section towards what is equivalent to becoming double in other tribes. Accordingly, the Chamomile, Anthemis nobilis, t. 980; Chrysanthemum Leucanthemum, t. 601 ; and some others, occasionally have their whole disk changed to ligulate white florets, destitute of stamens, and con- sequently abortive. Such are called double flowers in this Class, and very properly. Many exotic spe- cies so circumstanced are met with in gardens. A few very strange anomalies occur in this section, as already mentioned, p. 341, one Sigesbeckia having but 3 stamens, instead of 5, the otherwise universal number in the Class : and Tussilago hybrida, t. 430, as well as paradoxa of Retzius, having distinct an- thers. Nature therefore, even in this most natural Class, it is not without exceptions. 3. Polygamia frustranea. Florets of the disk, as in the preceding, perfect or united ; those of the margin neuter, or destitute of pistils as well as of stamens ; only some few genera having the rudiments of pistils in their radiant florets. 350 SYNGENESIA. This Order is, still more evidently than the last, analogous to double flowers of other Classes. Ac- cordingly, Coreopsis is the very same genus asBidens, only furnished with unproductive radiant florets. C. bidens of Linnaeus is the same species as in B. cer- nua ; C. coronata is his B. frondosa ; and C. leucan- tha, B. pilosa. Some species of Coreopsis indeed have never been found without rays. Linnaeus ex- presses his difficulties on this subject in Phil. Bot. sect. 209, but seems inclined to unite the two genera. A similar ambiguity occurs between Gorteria and Atractylis, Relhania (of the last Order) and Athana- sia, and in some degree between Centaurea, Engl. Bot. t. 278, 1678, 56, &c, and Carduus, or Serra- tula ; only the scales of the calyx of Centaurea gen- erally keep that genus distinct. I should be much inclined to abolish this Order, Those of its genera which have rudiments of pistils in their radiant florets,.as Rudbeckia and Helianthus, would very commodiously range with their near rela- tions in Polygamia superfiua, nor are we sure that such radiant florets are in all circumstances abortive, neither can a student often know whether they are so or not. It does not follow, from what has just been observed, that the presence of radiant florets, whether abortive or not, can never afford a generic character, provided there be no corresponding genus without them. This must be determined by experience and observation. They are indeed to be considered as a very secondary mark, the most essential in this Class being derived from the receptacle, crown of the seed. SYNGENESIA 351 and calyx. These Gaertner has illustrated with the greatest accuracy and skill, but even these must not be blindly followed to the destruction of natural gen- era. 4. Polygamia necessaria. Florets of the disk furnished with stamens only, those of the margin, or radius, only with pistils ; so that both are necessary to each other. This is well seen in the common Garden Ma- rigold, Calendula, in whose calyx, when ripening seed, the naked and barren disk is conspicuous. Othonna, Curt. Mag. t. 306, 768, Arctotis, Osteospermum and Silphium, not rare in gardens, are further examples of this Order, which I believe is constant and founded in nature. We have no British specimens either of it or the fellowing. Filago, at least as far as our Flora is concerned, belongs to Gnaphalium. See Engl. Bot. t. 946, 1193, &c. 5. Polygamia segregata. Several flowers, either simple or compound, but with united tubular anthers, and with a partial calyx, all included in one general calyx. Of these the Globe-thistle, Echinops, and Stoebe, with Seriphium and Corymbium, (which two last require to be removed hither from the abolished Linnaean Order Syngenesia Monogamia,) have only 1 floret in each partial calyx ; Jungia has 3, Elephantopus 4, others more. In every case the partial calyx is distinguished from the chaffy seed-crown observable in several gen- era of the other Orders, (though the latter is indeed analogous to a calyx,) either by being inferior, or by the presence of a seed-crown, or feathery down, be- 352 GYNANDRIA. sides. See Lamarck, t. 718—723, where the plants in question are well represented. Class 20. Gynandria. Stamens inserted either upon the style or germen. Orders 9 in Linnaeus, but some alterations concerning them are necessary. This is one of those Classes abolished by the celebra- ted Thunberg, and by several less intelligent writers who have followed him. The reasons which led to this measure appear to have been that Linnaeus has errone- ously placed in Gynandria several plants which have not the requisite character ; hence that character itself has been judged ambiguous, or not founded in nature, and the system has been supposed to be simplified by over- looking it. This appears to me a great mistake. The character of the Class, taken as above, is as evident, constant and genuine as that of any other in the system. No doubt can arise, if we be careful to observe that the stamens actually grow out of the germen or style, and not merely out of any part that supports the germen ; as will appear by examples. 1. Monandria. Stamen, or sessile Anther, 1 only. This contains all the beautiful and curious natural family of the Orchidea, or Orchis tribe, except only Cypripedium, which belongs to the next Order. I am induced to consider the bulk of this family as mo- nandrous, upon a careful review of Professor Swartz's representation of the subject, in his excellent treatise, just come to my hands in English. See Tracts rela- tive to Botany translated from different Languages GYNANDRIA. 353 (by Mr. Konig,) printed for Phillips and Fardon, 1805. I have already,/). 217, mentioned the glutin- ous nature of the pollen of these plants. This forms yellow elastic masses, often stalked, in each cell of the anther, and the cells are either parallel and close to- gether, or removed from each "other to the opposite sides of the style : which serves to connect them, just as the filament does in many Scitamineous plants, alike therefore decided to be monandrous. Such a decision with regard to those also is justified by the analogy of other species, whose cells being approxi- mated or conjoined, properly constitute but one an- ther. The grand and absolute subdivision of the Orchidea is justly founded by Dr. Swartz, after Hal- ler, on the structure of the anther, whether it be, as just described, parallel, like that of Orchis, Engl. Bot. t. 22 ; Ophrys, t. 65 ; and Diuris, Exot. Bot. t. 9, &c.; or vertical, consisting of a moveable lid on the top of the style, like Dendrobium, t. 10—12 ; or Ma- laxis, Engl. Bot. t. 72. The style of the Orchidea has been called a column, but I think that term now altogether superfluous. It is really a style, and the stigma is a moist shining space, generally concave, and situated, for the most part, in front of the style beneath the anther. In Orchis bifolia, t. 22, and others, it is just above the orifice of the spur. Con- cerning the nectary of these plants there has been much diversity of opinion. The calcar, spur, in Or- chis, and some other genera, is acknowledged to be such, and holds abundance of honey. This spur is judged by S.vurtz, as well as Linnaeus, a decisive WW 54 GYNANDRIA. generic mark of distinction, and it commonly is so; but some Indian species brought by Dr. Buchanan prove it not to be absolute. The remarkable and often highly ornamented lip, considered by Swartz as the only corolla, for he takes all the other leaves of the flower for a calyx, has, by Linnaeus and others, been thought, either a part of the nectary, or, where no spur is present, the only nectary. Nor is this opin- ion so ill-founded as many botanists suppose ; for the front of the lip evidently secretes honey in Ophrys (or Epipactis) ovata, t. 1548, and probably in others not yet attended to. Nevertheless, this lip might, like the petals of lilies, be deemed a nectariferous corolla, were it certain that all the other leaves were truly a calyx. But the 2 inner are so remarkably different from the 3 outer ones in Ophrys, t. 64, 65, 71, 383, and above all, in Stelis, Exot. Bot. t. 75, that I am most inclined to take the former for the corolla, the latter being, according to all appearance, a calyx. An insensible gradation from one to the other, of which we have pointed out other instances in treating of this subject already, occurs in Diuris, t. 8, 9 ; while in some Orchidea the leaves all partake more of the habit of a calyx, and in others of a corolla. Even the lip in Thelymitra, t. 29. assumes the exact form, colour, and texture, of the rest of the flower ; which proves that a dissimilarity between any of these parts is not always to be expected in the family under consideration. Vahl appears by the preface to his Enumeratio Plantarum to have removed the Scitami- nea to Gynandria, because the stamen of Canna ad* GYNANDRIA. 356 heres to the style. This, if constant, could only con- cern that genus, for the rest of the Order are in no sense gynandrous. 2. Diandria. To this Order Cypripedium, Engl. Bot. t, 1, must be referred, having a pair of very distinct double-celled anthers. See Tr. of Linn. Soc. v. 1.1. 2, 3. Here we find Forstera, so well illustrated by Professor Swartz in Sims and Konig's Annals of Bot- any, v. 1. 291, t. 6 ; of which genus Phyllachme, t. 5 of the same volume, is justly there reckoned a spe- cies. Of the same natural order with Forstera is Sty- lidium, but that having I think, 4 anthers, belongs to the fourth Order of the present Class. Gunnera, plac- ed by Linnaeus in Gynandria Diandria, is not yet sufficiently well understood. 3. Triandria. Salacia, if Linnaeus's description be right, is properly placed here ; but Jussieu doubts it, nor does my dried specimen serve to remove the uncertainty. Stilago proves to be merely the barren plants of Antidesma alexiteria, and belongs to Dioecia ; as Sisyrinchium and Ferraria do to Monadelphia, the tubular united stamens of the two last having been mistaken for a solid style. Rhopium of Schreber (Me- borea oiAublet, t. 323,) seems therefore the only cer- tain genus of the Order under consideration ; unless Lamarck be right in referring to it Jacquin's Strump- fia, upon which I have not materials to form any opin- ion. The original discoverer attributes to this plant 5 stamens with united anthers; hence it found a place in the Syngenesia Monogamia of Linnaeus. Lamarck 356 ttYNANDRIA. merits attention, as he appears to have had an authen- tic specimen. See his t. 731. 4. Tetrandria. Nepenthes, of whose extraordinary kind of leaf mention is made p. 162, is the only genus of this Order in Linnaeus, but very erroneously plac- ed here, for it belon gs to Dioecia Monadelphia. The Order however must be retained for the sake of Styli- dium, a New Holland genus, related, as above men- tioned, to Forstera. This is my Ventenatia, Exot. Bot. t. 66, 67 ; but another genus having previously, without my knowledge, received the latter denomina- tion, that of Stylidium, under which I had, some time ago, communicated this genus to the French botan- ists*, and which they have adopted, becomes estab- lished. See La Billardiere's excellent work on New Holland plants, where several species of it are figured. 5. Pentandria. The original genera of this Order, Ayenia, Gluta, and Passflora, Exot- Bot. t. 28, most unquestionably have nothing to do with it, their sta- mens being inserted below the germen, merely on a columnar receptacle. The learned Schreber there- fore removed them to the 5th Class. But this Order may receive a reinforcement from the Linnaean Pentandria Digynia. Several of the * I was not aware of Loureiro's Stylidium, a plant, according to his description, of the 7th, Class; Fl. Cochinch. v. 1.221 ; but this can scarcely interfere with ours, being probably, as it grows about Canton, some well-known shrub that happened to have a 7-cleft flower. It should seem to belong to the Rubiaceee, not- withstanding some points in the description. GYNANDRIA. 35.7 Contorta have long been thought to belong to Gynan- dria; see Pergularia, Ic. Pict. t. 16, and Ander. Re- pos. t. 184. In this genus, as well as Cynanchum and Asclepias, the pollen is borne in 5 pair of glutin- ous masses, exactly like the pollen of Orchidea, by 5 glands upon the stigma. Some obscurity arises from each mass of pollen being received into a bag or cell, formed by a peculiar valvular apparatus that encircles the organs of impregnation, and bears a great resem- blance to stamens. The pollen however is, in the above genera, not attached to these cells or valves, but to the 5 glands, each of which is double, and all of them seated on that thick abrupt angular body which acts as a stigma*. Nor is it worth while to dispute whether this whole body be a stigma or not, with re- gard to the question under consideration, for it is borne by the styles, above the germen, and itself bears the anthers. I humbly conceive, however, with Lin- naeus and Jacquin, that as part of it, at least, receives the pollen, stigma is full as good a name for this body as Haller's term dolium, a tub ! Still less is it worth while to controvert with Kolreuter the propriety of the term pollen, because the substance in question is not actually a dry powder, any more than in the Or- chis tribe, or in Mirabilis, Exot. Bot. t. 23. That term is technically used for the matter which renders the seeds fertile, including its vehicle, whether the * Mr. R. Brown believes the cells secrete the pollen, and pro- ject it on the stigma, as the pollen of some Orchidea stick to any part of the plant,. If so, these plants must remain in Pen- tandria. 358 GYNANDRIA. latter be capsular or glutinous, in short, whatever the appearance or texture of the whole may be. Anoth- er question remains, more immediately to our present purpose, whether these plants have 5 stamens or 10 ? Jacquin, who has well illustrated several of them in his Miscell. Austr. v. 1. t. 1—4, and Rottboll in a dissertation on the subject, contend for the latter. Rottboll wrote to Haller, that " finding Linnaeus deaf to all that had been said, he sent him his treatise, to see whether he would persist in falsifying nature." Thus sordid underlings foment the animosities and flatter the failings of their superiors ! Linnaeus judi- ciously suspended his opinion, and, after all, proves to be most correct. The annalogies of the Orchidea and Scitaminea very clearly decide that the 2 cells, or the double masses of naked pollen, can only be considered as one anther of 2 lobes. Even Periploca graca, though not gynandrous, confirms this. Each lobe of its anthers stands, as in many Scitaminea, on the outermost edge of the filament ; thus meeting that on the adjoining filament, and in appearance con- stituting with it a 2-lobed anther, as the lobe of the Sci- taminea, where there is but one filament, meets its cor- responding lobe by embracing the style. *6. Hexandria. Aristolochia, Engl. Bot. t. 398, a curi- ous genus, of which there are many exotic species, is the only example of this, Pistia being removed to Monadelphia Octandria. ' 7. Octandria. The Scopolia of Linnaeus, which origi- nally constituted this Order, proves to be a Daphne ; CYNANDRIA. 35$ see Piant. Ic. ex Herb. Linn. t. 34. Cytinus how- ever, Cavan. Ic. t. 171, a singular parasitical plant on the roots of Cistus in the south of Europe, has pro- perly been brought hither from the Order Dodecan- dria, of which it originally formed the only example. The observations of Dr. Sibthorp and Mr. Ferd. Bauer confirms those of other botanists, that the an thers are 8, not 16, and that they are truly inserted upon the style. 8. Decandria is now abolished. Of the two genera which constituted it, Kleinhovia belongs to the Class Dodecandria, having 15 stamens, see Cavan. Mona- delph. t. 146 ; and Helicteres to Decandria Mono- gynia. 9. Dodecandria is likewise abolished. 10. Polyandria is in a similar predicament, for I am not aware of any genus that can be admitted into it. Xylopia goes with the greatest propriety to its natural allies in Polyandria Polygynia, Annona, &c, its short stamens being inserted into the receptacle below the germen. Grewia, as well as Schreber's Microcos if a good genus, belong to Polyandria Monogynia, the organs of impregnation being merely elevated on a common stalk, like those of Passifiora and Ayenia. Ambrosinia, Arum, and Calla, are all justly removed by Schreber to Monoecia, though I think, for reasons hereafter given, they are more commodiously and naturally placed in the Order Polyandria of that Class, 360 MONOECIA. than in the Order Monandria. Dracontium+md Po those of the same natural family, having perfect or uni- ted flowers, the former with 7 stamens to each, the latter with 4, are undoubtedly to be referred to their cor- responding Classes, Heptandria and Tetrandria- Zostera, the only remaining genus of Gynandria Polyandria in Linnaeus, I have long ago ventured to remove to Monandria Monogynia ; see Engl. Bot. t. 467. Class 21. Monoecia. Stamens and Pistils in sepa- rate flowers, but both growing on the same individual plant. Orders 9 or 10. Several reformers of the Linnaean system have also abolished this Class and the two following, by way of rendering that system more simple. Ten years' ad- ditional experience since the preface to the 7th vol- ume of English Botany was written, have but con- firmed my opinion on this subject. If any plants ought to be removed from these Classes, they must be such as have the structure of all the accessory parts of the flower exactly alike, (the essential parts, or stamens and pistils only, differing,) in both barren and fertile flowers ; and especially such as have in one flower perfect organs of one kind, accompanied by rudiments of the other kind, for these rudiments are liable occasionally to become perfect. By this means dioecious species of a genus, as in Lychnis, Valeriana, Rumex, &c, would no longer be a re- proach or inconvenience to the system. But, on the other hand, some difficulty would occasionally arise MONOECIA, 361 to a student, in deciding whether there were any real difference of structure between these accessory parts or not, and it might puzzle an adept to determine the question. For instance, whether the nectary in Salix, different in the barren and fertile flowers of some spe- cies, should lead us to keep that genus in Dioecia, though in other species the nectary is precisely alike in both the kinds, and occasionally an abortive ger- men occurs in the barren flowers, as stamens do, more rarely, in some fertile ones. Considering all this, I should refer Salix to Diandria Monogynia. With respect to those Monoecious or Dioecious genera whose barren flowers are decidedly unlike the fertile ones, the former being in a catkin, the latter not, as Corylus, Quercus, &.C., I conceive nothing more pernicious or troublesome can be attempted than to remove them to the Classes of united flowers. They meet with no allies there, but, on the contrary, form so natural an assemblage by themselves, as to be unanimously kept separate by the authors of every natural system that has appeared. But even if this Were not the case, there is a most important reason for keeping them as they are, which regards the artificial system more particularly, and of which its author was well aware ; they are of all plants most uncertain in the number of their stamens. Now this uncertaintv is of little moment, when we have them primarily distinguished and set apart from other plants by their Monoecious or Dioecious character; because the genera being few, and the Orders constructed widely as to number of Stamens, we find little diifi- xx MONOECIA. culty in determining any genus, which would be by no means the case if we had them confounded with the mass of the system. Even the species of the same genus, as well as individuals of each species, differ among themselves. How unwise and unscien- tific then is it, to take as a primary mark of discrim- ination, what nature has evidently made of less conse- quence here than in any other case! It is somewhat like attempting a natural system, and founding its primary divisions on the artificial circumstance of number of stamens. I proceed to give some illustrations of the Orders in Monoecia. 1. Monandria. Zannichellia, Mill. Illustr. t. 77, and Aegopricon, Plant. Ic. ex Herb. Linn. t. 42, are gen- uine examples of this Class and Order, having a dif- ferent structure in the accessory parts of their barren and fertile flowers. Artocarpus, the celebrated Bread- fruit, may likewise be esteemed so on account of a partial calyx in the barren flower. The other amen- taceous genera may most intelligibly perhaps be re- ferred to the Order, Polyandria. Chara is now re- moved to the first Class in the system ; see Eng. Bot. . t. 336. 2. Diandria. Anguria can remain here only till the pro- posed reformation takes place, having no difference of ■tructurein its flowers. Lemna, so imperfectly known when Linnaeus wrote, is now well understood, and, having frequently united flowers, belongs to the sec- ond Class ; see Engl. Bot. t. 926, 1095, 1233, MONOECIA. 363 3. Triandria. The great genus of Carex, t. 1051,928, 993—995, &c, and some other grassy plants, are found here. Typha, t. 1455—1457, is less clear in its structure; Sparganium, t. 744, 745, 273 is suffi- ciently so. Tragia, Hernandia and Phyllanthus are properly placed in this Class and Order. 4. Tetrandria. Littorella, t. 468 ; the valuable genera Betula, t. 1508, and Buxus, t. 1341; also the Net- tle Urtica, t. 1236 ; are good examples of this. Mo- rus the Mulberry, of the same natural order as the Nettle, has scarcely any difference of structure in the accessory organs of the flowers. This tree however is remarkable for being often inclined to become even dioecious in its constitution, one individual bearing most fruit when occompanied by another whose barren flowers are more effective than its own. Empleurum, Exot. Bot. t. 63, is one of those^ambiguous genera which are but imperfectly monoecious, 5. Pentandria. Xanthium, Ambrosia, Nephelium, Par- thenium, Iva and Clibadium all partake, more or less accurately, of the nature of compound flowers, but their anthers not being united, they could not be re- ferred to the Class Syngenesia ; particularly Xanthi- um and Nephelium, whose fertile flowers have no re« semblance to that Class. Amaranthus, an extensive dunghill genus in warm countries, analogous to our Chenopodium, follows next. Leea is the same with Aquilicia, and belongs to Pentandria Monogynia, the former name being retained for the sake of the highly meritorious botanist and cultivator whom it commem- 364 MONOECIA. orates. The Gourd tribe, (142) Cucurbita, Cucumis, Bryonia, Engl. Bot. t. 439, might be brought hither from the abolished Order Syngenesia, unless it should be thought better to consider them as polyadelphous, to which I am most inclined. 6. Hexandria. Zizania, Tr. of Linn. Soc. v. 7. t. 13 ; and Pharus, Browne's Jamaica, t. 38, both grasses, compose this Order, to which Schreber has added Epibaterium and Pometia of Forster, as well as the splendid Guettarda, Hort. Mai. v. 4. t. 48. The latter varies from 6 to 9 in the parts of the flower, and constitutes the Order Heptandria in Linnaeus, according to his usual principle, of placing such ir- regular plants, as much as possible, in small Classes or Orders, that they might be the more easily found. 7. Polyandria, Stamens more than 7. Ceratophyllum, Engl. Bot. L 947, 679 ; Myriophyllum, t. 83, 218 ; and the handsome Sagittaria, t. 84, stands here at present, but the accessory parts in their two kinds of flowers are alike. Begonia, Exot. Bot. t. 101, has the number of its petals, though various in several species, always sufficiently different in the barren and fertile flowers to fix it here.—/The most indubitable " plants of this Order are amentaceous, (143) Quercus, Engl. Bot. t. 1342 ; Fagus, t. 886 ; Corylus, t. 723 ; (142) [The Cucurbitacee, or Gourd tribe of Linnaeus, include the Melon, Cucumber, Pumpkin, and others of similar fruit. The Passion Flower is referred to this natural order.] (143) [The A,mentace cd to is that the process should meet with no check. Several vegetables are so tenacious of their vital princi- ple, that they will grow between papers, the conse- quence of which is a destruction of their proper habit and colours. It is necessary to destroy the life of such, either by immersion in boiling water, or by the applica- tion of a hot iron, such as is used for linen, after which they are easily dried. I cannot however approve of the practice of applying such an iron, as some persons do, with great labour and perseverance, till the plants are quite dry, and all their parts incorporated into a smooth flat mass. This renders them unfit for subsequent ex- amination, and destroys their natural habit, the most important thing to be preserved. Even in spreading plants between papers, we should refrain from that pre- cise and artificial disposition of their branches, leaves, and other parts, which takes away from their natural as- pect, except for the purpose of displaying the internal parts of some one or two of their flowers, for ready ob- servation. After all we can do, plants dry very variously. The blue colours of their flowers generally fade, nor are reds always permanent. Yellows are much more so, but very few white flowers retain their natural aspect. The Snowdrop and Parnassia, if well dried, contin- ue white. Some greens are much more permanent than others ; for there are some natural families whose leaves as well as flowers turn almost black by drying, as Melampyrum, Bartsia, and their allies, several Wil- lows, and most of the Orchidea. The Heaths and Firs in general cast off their leaves between papers, 3ft6 PRESERVATION OF which appears to be an effort of the living prin- ciple, for it is prevented by immersion of the fresh specimen in boiling water. Nandina domestica, a Jap- anese shrub, lately introduced among us by Lady A. Hume and Mr. Evans of Stepney, is very remark- able in this respect. Every leaflet of its very com- pound leaves separates from its stalk in drying, and even those stalks all fall to pieces at their joints. Dried specimens are best preserved by being fas- tened, with weak carpenter's glue, to paper, so that they may be turned over without damage. Thick and heavy stalks require the additional support of a few transverse strips of paper, to bind them more firmly down. A half sheet, of a convenient folio size, should be allotted to each species, and all the species of a genus may be placed in one or more whole sheets. On the latter the name of the genus should external- ly be written, while the name of every species, with its place of growth, time of gathering, the finder's name, or any other concise piece of information, may be inscribed on its appropriate paper. This is the plan of the Linnaean Herbarium, in which every spe- cies, which its original possessor had before him when he wrote his great work the Speeies Plantarum, is numbered both in pencil and in ink, as well as nam- ed, the former kind of numbers having been tempo- rary till the book to which they refer was printed, af- ter which they were confirmed with a pen, and a co- py of the book, novv also in my hands, was marked in reference to them. Here therefore we do not de- pend on the opinion merely, even of Linnaeus, for we AN HERBARIUM. 38'7 have always before our eyes the very object which was under his inspection. We have similar indica- tions of the plants described in his subsequent works, the herbarium being most defective in those of his 2d Mantissa, his least accurate publication. We often find remarks there, made from specimens acquired after the Species Plantarum was published. These the herbarium occasionally shows to be of a different species from the original one, and it thus enables us to correct such errors. The specimens thus pasted, are conveniently kept in lockers, or on the shelves of a proper cabinet. Lin- naeus in the Philosophia Botanica exhibits a figure of one, divided into appropriate spaces for each class, which he supposed would hold his whole collection. But he lived to fill two more of equal size, and his herbarium has been perhaps doubled since his death by the acquisitions of his son and of its present posses- sor. One great and mortifying impediment to the per- fect preservation of an herbarium arises from the at- tacks of insects, A little beetle called Ptinus Fur is, more especially, the pest of collectors, laying its eggs in the germens or receptacle of flowers, and others of the more solid parts, which are speedily devoured by the maggots when hatched, and by their devastations paper and plants are alike involved in ruin. The most bitter and acrid tribes, as Euphorbia, Gentiana, Prunus, the Syngenesious class, and especially Wil- lows, are preferred by these vermin. The last-men- tioned family can scarcely be thoroughly dried before Itffc PRESERVATION OF AN HERBARIUM. it is devoured. Ferns are scarcely ever attacked, and grasses but* seldom.—To remedy this inconvenience I have found a solution of corrosive sublimate of mercurv in rectified spirits of wine, about two drams to a pint, with a little camphor, perfectly efficacious. It is easily applied with a camel-hair pencil when the specimens are perfectly dry, not before ; and if they are not too tender, it is best done before they are pas- ted, as the spirit extracts a \ellow dye from many plants, and stains the paper. A few drops of this so- lution should be mixed with the glue used for pasting. This application not only destroys or keeps off all vermin, but it greatly revives the colours of most plants, giving the collection a most pleasing air of freshness and neatness. After several years' experi- ence, I can find no inconvenience from it whatever, nor do I see that any dried plants can long be preserv- ed without it. The herbarium is best kept in a dry room without a constant fire. Linnseus had a stone building for his museum, remote from his dwelling-house, into which, I have been told, neither fire nor candle was ever ad- mitted, yet nothing can be more free than his collec- tion from the injuries of dampness, or other causes of decay. C 389 ] EXPLANATION OF THE PLATES. Tab. I-fig- 1. Anatomy of wood, after Mirbel. See p. 30. f. 2. Embryo of Pinus Cembra, shown in a section of the seed, then separate, and magnified, from Mr. Lambert's work. See p. 91, 229. f 3. Seedling plants of the Dombeya, or Norfolk Island Pine, with its 4 cotyledons, and young leafy branches of the natural size, p. 91. f. 4. A garden bean, Vicia Fabia, laid open, showing its 2 cotyledons, p. 90 ; f the radicle, or young root, p. 90 ; g the germ or corculum, p. 90. Above is a bean which has made some progress in vegetation, showing the descending root, the ascending plumula. and the skin of the seed bursting irregularly. Tab. 2. Roots, f. 5. Fibrous, in Grass, p. 96. f. 6. Creeping, Mint, p. 96. f. 7. Spindle-shaped, Rad- ish, accompanied by its cotyledons and young leaves, p. 197. f 8. Abrupt, Scabiosa succisa : f.9. Tube- rous, Potatoe, p. 198. f. 10. Oval knobs of some Orchidea: f. 11. Palmate ones of others : y*12. Several pairs of knobs in Satyrium albidum : p. 109. f. 13. solid Bulb in Crocus: f. 14. Tunicate Bulb in Allium: f. 15. Scaly one in Lilium : p. 100. f. 16. Granulated Root of Saxifraga granulata, p. 101. 360 EXPLANATION OF THE PLATES. Tab. 3. Stems and Buds. f. 17. Forked Stems, in Chlora perfoliata, p. 105. f. 18. Scaly, in Oroban- che : f 19. Radicans, or Clinging, in Ivy,/). 106. f. 20. Twining from left to right, in Lonicera ;f.2l: from right to left, in Convolvulus, p. 107. f. 22. Sarmentum, a Runner, in the Strawberry, p. 108. f. 23. Caulis determinate ramosus, as in the Azalea, family, p. 122. / 24. Three pair of Buds, in Loni- cera carulea, f. 25. Bud of thd Horse Chesnut, p. 137. Tab. 4. Leaves. / 26. Tufted leaves, p. 126. f. 27. Imbricated : f 28, Decussated : f. 29. Two-ranked, Yew : / 30. Unilateral,/;. 147. / 31. Peltate, Nas- turtium, p. 149. f. 32. Clasping the stem, p. 150. / 33. Perfoliate : f. 34. Sheathing:/ 35. Equitant: f. 36. Decurrent, p. 130, and spinous, p. 162. f. 37. Flower-bearing, Ruscus aculeatus, p. 130. Tab. 5. / 38. Orbicular, Hedysarum styracifolium, p. 131. / 39. Roundish, Pyrola : f 40. Ovate : / 41. Obovate : fA2. Elliptical or oval : f. 43. Spatulate, p. I54.fi 44. Wedge-shaped : f. 45. Lanceolate : / 46. Linear : / 47. Needle-shaped : / 48. Trian- gular, p. 155. f. 49. Quadrangular, (also abrupt, p. 159), Tulip-tree : / 30. Deltoid : / 51. Rhomboid : / 52. Kidney-shaped,p. 133. / 53. Heart-shaped: f 54. Crescent-shaped : f 55. Arrow-shaped : f. 56. Halberd-shaped, (also acute, p. 137),/57. Fiddle- shaped, (also obtuse, p. 137), Rumex pulcher, p. 157. / 58. Runcinate : / 59. Lyrate : / 60. Cloven : / EXPLANATION OF TUB PLATES. 391 61. Three-lobed, Anemone Hepatica : f 62. Sinua- ted, Oak : / 63. Deeply divided, HeUeborus, p. 135. / 64. Laciniated : Tab. 6. / 65. Palmate : / 66. Pinnatifid : f. 67. Doubly pinnatifid, p. 136. / 68. Pectinate : / 69. Unequal, Begonia : f 70. Jagged-pointed, p. 160. f.7\. Retuse, Rumex digynus : f 72, Emarginate : / 73. Pointed : / 74. Blunt with a small point, p. 161. / 75. Sharp pointed, Ruscus aculeatus : / 76. Cirrose : / 77. Spinous, p. 138. / 78. Frin- ged : / 79. Toothed : / 80. Serrated : / 81. Crenate, p. 139. Tab. 7. / 82. Doubly as well as sharply crenate, ap- proaching to / 80. : / 83. Jagged : / 84. Wavy, Menyanthes nymphaoides : f. 85. Plaited, p. 165. / 86. Undulated ;/ 87. Curled,p. 141./ 88. Veiny : / 89. Ribbed : / 90. Three-ribbed, p. 167./ 91. Three—ribbed at the base : / 92. Triply-ribbed : / 93. Cylindrical, Conchium, p. 142. / 94. Semicy- lindrical: / 95. Awl-shaped :/ 96. Doubly tubular, Lobelia Dortmanna:f. 97. Channelled,/?. 143./98. Hatchet-shaped, p. 171. / 99. Three-edged, Mes- embryanthemum deltoides: f. 100. Four-edged : Tab. 8. / 101. Alienated, Mimosa virticillata, p. 145.* / 102. Hooded, Sarracenia,p. 146. / 103. * I have found by recent experiment, that the first leaf of Xathi/rus JVissolia is like the rest, not pinnated, but simple and pessiie. See ft. 173. 392 EXPLANATION OF THE PLATES. Furnished with an appendage, Dionaa muscipula: f. 104. Jointed, Fagara tragodes, p. 149./ 105. Bin- ate,/?. 148. / 106. Ternate: / 107. Interruptedly Pinnate, p. 148. / 108. Pinnate in a lyrate form, p. 149./ 109. Pinnate in a whorled manner, p. 150. / 110. Auricled:/ 111. Compound, p. 150. / 149. Doubly compound, or Twice ternate: / 113. Thrice compound, or Thrice ternate : / 114. Pedate, Helleborus, p. 151. Tab. 9. Appendages. / 115. Stipulas of Lathyrus Jatifolius, p. 178 ; also an abruptly pinnated leaf, end- ing in a tendril, p. 176. / 116. Stipulas united to the footstalk, in Rosa, p. 178 ; also a pinnated leaf with a terminal leaflet, p. 148. / 117. Floral leaf of Tilia, p. 180. / 118. Coloured floral leaves, Lavan- dula Stoechas : f. 119. Spinous ones, Atractylis can- cellata : f. 120. Thorns, Hippophae rhamnoides, p. 223. f 121. Prickles, p. 182. / 122. Tendril, Lathyrus latifolius : f. 123. Glands of the Moss Rose, p. 226. f. 124. Hairs : /. 125. Bristles of Echium pyrenaicum, p. 185. Tab. 10. Inflorescence. / 126. Whorl, in Lamium, p. 188./ 127. Whorled leaves, and axillary flowers, of Hippuris vulgaris, p. 188. / 128. Cluster, Ribes : f. 129. Spike, Ophrys spiralis : f. 130. Less correct Spike, Veronica spicata, p. 180. / 131. Spikelet, Br ornus, p. 189. /. 132. Corymb : / 133. Corym- bose fascicle, Achillea, p. 190. / 134. Fascicle, Dianthus Armeria, p. 190. / 135. Head or Tuft, EXPLANATION OF THE PLATES 395 Trifolium : f 136. Simple Umbel, Eucalyptus pi- perita, p. 191. / 137. Simple Umbel in th- natural order of Umbellata, Astrantia major, with the Involu- crum, a : Tab. 11. / 138. Compound Umbel, Laserpitium simplex, with its general Involucrum, a, and partial one, b, p. 198. / 139. Cyme, Laurustinus, p. 192. / 140. Panicle, Oat,/?. 192. / 141. Banch, Com- mon Vine, p. 193. , Calyx. / 142. Perianthium, or Calyx properly so called, Dianthus deltoides, p. 197. / 143. Involu- crum, so called, in Anemone, p. 198. / 144. Invo- lucrum or Indusium of Ferns, p. 199. / 145. One of the same separate, with a capsule and its ring. / 146. Catkin of the Hasel-nut p. 200. Tab. 12. Calyx and corolla, with Nectary. / 147. Sheath of the Narcissus ; a, the Petals, called by Jussieu, Calyx; b, the Crown or Nectary, seep. 212. / 148. /Husk of Grasses, p. 201. / 149. Awns. / 150. Scaly Sheath, Pterogonium Smithii, p. 201. / 151. Veil of the same, p. 203. / 152. Jun- germannia epiphylla, showing a, the Calyx, p. 201; b, the Veil or Corolla, p. 203 ; and c, the uno- pened Capsule. /. 153. Wrapper, Agaricus : f 154. Radical Wrapper, p. 203.fi 155. Monopetalous Salver-shaped Corolla, p. 206. / 156. Polypet- alous Cruciform Corolla : / 157. A separate Petal cbd 3J4 EXPLANATION OF THE PLATES. of the same ; a, Claw ; b, Border ; / 158« Unequal Corolla, Butomus, p. 206. Tab. 13. / 159. Bell-shaped Corolla : / 160. Fun- nel shaped: / 161. Ringent :/. 162. Personate, Antirrhinum reticulatum, p. 207. / 163. Papiliona- ceous, Lathyrus ; f. 164. Standard of the same ; / 165. One of the Wings ; / 166. Keel ; / 167. Stamens, style Sec,; / 168, Incomplete Corolla, Rit- tera.fi 169. Peloria, or regular-flowered variety of Antirrhinum Linaria, p. 207. / 170. Nectary in the Calyx of Tropaolum : / 171. Nectary of Aquilegia, p. 266. / 172, 173. The same part in Epimedi- um : f. 174. Pair of Nectaries in Aconitum, p. 214. / 175. Fringed Nectaries in Parnassia, p. 214. Tab. 14. Stamens, Pistils and Fruit. / 176. A Sta- men : a, filament ; b, anther, p. 217. / 177. Pistils : a, g-ermen ; b, style; e, stigma, p. 218. / 173. Capsule of an annual Mesembryanthemum, open and shut,/>. -:-21. / 179. Transverse section of the capsule oi Datura, p. 221, showing the partitions and columella, f 180. Sdiqua, or Pod : / 181. Silicula, or Pouch, p. 222. f 182. Legume, p. 223./ 183. Stone-fruit,/*. 282. / i84. Apple : / 185. Berry : / 186. Compound Berry, p. 225. f 187. Berry of Passifiora suberosa, p. 284. / 188. Cone, Larch, p. 227. / 189. Capsule of a Moss, Splachnum, with its fleshy base, or apophysis, a, and fringe, b, p. $74. EXPLANATION OF THE PLATES. 396 Tab. 15./ 190. Barren flower of a Moss, much mag- nified, after Hedwig : / 19!. Stamens, with the Pol- len coming forth, and the jointed filaments, p. 275. / 192. Fertile flower of a Moss, consisting of num- erous pistils, only one of which in general comes to perfection. They are also accompanied by jointed filaments: / 193. A germinating seed of Gymnos- tomum pyriforme, from Hedwig likewise, showing its expanding embryo: / 194. The same more advan- ced : / 195. The same much further advanced, and become a young plant,showing its leaves and branched cotyledons,/;. 274. / 19 . Young plant of Funaria hygrometrica, exhibiting the same parts, p. 276. / 197. Powdery wart of a Lichen, presumed to be its barren flower : / 198. Perpendicular section, magni- fied, of the shield or fruit of a Lichen, showing the seeds imbedded in its disk, p. 3 77. / 199. Section of the seed of a Date, Phoznix dactylifera, from Gaertner, the bulk of which is a hard Albumen, p. 230, having a lateral cell in which is lodged the horizontal embryo,a,p. 229. / 2(10. Section of the Vitellus in Zamia, from the same author, with its embryo a, with which it is, like a co- tyledon, closely connected,/?. 231. / 201. Rough coats of the seeds in Cynoglossum, p. 298. / 202. Arillus of a Cafex, p. 235. f 203. Seed of Afzelia, with its cup-shaped Arillus.p. 235.fi. 204. Pappus, or seed-down, of Tragopogon, p. 237. f. 205. Tail of the seed in Dryas : f 206. Beaked fruit of Scandix, with its seeds separating from their base, p. 238. / 207. Winged seed of Emhothrium, p. 238. f. 396 EXPLANATION OF THE PLATES 208. Section of the conical Receptacle of the Daisy, with its calyx : /. 209. Cellular Receptacle of Ono- pordum,p. 241. / 210. Ligulate floret with both stamens and pistil, in a Dandelion, p. 242./ 211. Ligulate floret with only a pistil, in the radius of a Daisy, p. 242. / 212. Tubular floret from the disk of the same, having stamens and a fertile pistil, p. 242, / 213. Capsule of a Moss with a double fringe, the lid shown apaft,*^. 373. / 214. A portion of the same fringe magnified,/?. 374. £ 397 J INDEX I. INDEX OF REMARKABLE PLANTS, OR THOSE OF WHICH ANY PARTICULAR MENTION, OR ANY CHANGE IN THEIR CLASSfr FICATION, IS MADE. Abroma, 345 Abrus Preccttorius, 344 Acer, 326 ----saccharinum, 67 iEsculus Hippocastanum, 120 Agrimonia, 283 Ailanthus, 369 Alga, 377 Alopecurus bulbosus, 102 Amaranthus, 363 Amaryllis formosissima, 251 Ambrosinia, 365 Anagallis, 258 Angiopteris, 300 Annona hexapetala, 184 Aponogeton, 324 Aquilicia, 363 Arenaria, 261 Aristolochia Clematitis, 263 ----------Sipho, 263 Arum, 85 Ash, 62 Asperifoliae, 320 Athrodactylis, 366 Atriplex, 369 Aucuba, 288 , Bamboo, 73 Barberry, 255 Bauhinia, 291 Black rose, 82 Blandfordia, 281 Bonapartea, 270 Brodisea, 211 Browallia, 297 Bryonia, 297 Bubroma, 345 Buffonia, 297 Cactus coccinellifer, 265 Cxnopteris, 300 Calamagrostis, 300 Calceolaria, 289 Calla, 359 Canna, 354. Cannabis, 398 INDEX l Capura, 323 Carpinus Betulus, 201 'Caryocar, 337 Caryophyllus, 330 Celosia, 254 Ceratonia, 370 Ceratopelatum, Chara, 361. Cherry, double-blossomed, 219 Chrysanthemum indicum, 77 Cistus creticus, 156 Citrus, 346 Cleome, 337 Climbing plants, 107. Cluytia, 368 Coffee, 268 Columniferae, 339 Conchium, 291 Conferva bullosa, 173 Contorts, 321 Coriaria, 369 Cornus mascula, 156 Corymbium, 349 Cucumis, 364 Cucurbita, 364 Cuscuta, 319 Cyamus Nelumbo, 287 Cycas revoluta, 259 Cytinus, 358 Darea, 302 Devil's-bit, 97 Dicksonia, 292 Dictamnus albus, 156 Dillenia, 291 Dionaca muscipula, 146 Dodecatheon Meadia, 35 Dog-rose, 250 Dombeya, 91 Dorstenia, 291 Dracontium, 360 Epimedium alpinum, 280 Eriocalia, 371 Ervum, 347 Euclea, 370 Euphorbia, 365 Ferns, 371 Ficus, 262, 376 Filices, 371 Flores tristes, 78 Fontainesia, 290 Fraximus Ornus, 157 Fungi, 389 Gentiana, 289 Glaucium phcenicium, 253 Glycyrrhiza, 289 Goodenia, 290 Gourd tribe, 364 Grasses, 318 ® Grewia, 359 Guettarda, 364 Gundelia, 290 Gypsophila, 289 Hastingia coccinea, 311 Hedysarum gyrans, 172 Helianthus ainnus, 171, 15A INDEX I. 399 Helianthus tuberosus, 98 Helicteres, 366 Hemerocallis, 289 Hemp, 258 Hepaticae, 376 Hernandia, 291 ..» .'' Hillia, 297 Hippomane Mancinella, 167 Hippophae rhamnoides, 367 Hippuris, 349 Holmskioldia, 311 Hop, 157 Horse-chesnut, 12Q Humea, 290 Jatropha urens, 251 Jerusalem artichoke, 98 Jungermannia, 376 Kalmia, 255 Klcinhovia, 259 Knappia, 2i>2 Lace-bark, 38 Lachenalia tricolor, 101 Lasiopetalum,289 Lathyrus Aphaca, 180 Lavatera arborea, 95 Leea, 363 Lemna, 344, 361 Lichen, 377 Liliacese, 323 Lilium buibiferum, 61, Linnae-i, 291 Lithospermum, 289 Liverworts, 376 Lobelia longiflora, 167 Lonicera c»rulea, 118 Lurid*, 320 Magnolia, 291, 323 Maltese oranges, 82 Malvacese, 339 Marchantia, 376 Meadow Saffron, 349 Melaleuca, 346 Mentha, 335 Mimosa pudica, 210 ———sensitiva, 172 Mirabilis, 357 Monocotyledones, 60 Mensonia, 346 Morus, 364 Mosses, 372 Murrseu, 296 Musa, 250 Musci, 372 Mussxnda, 181 Mysosolis, 187 Mytistica, 369 Myrti, 330 Nandina domestica, 387 Nastus. 73 Neluinbium, 287 Nepenthes disiillatoria, 356 146 Nopal, 265 Norfolk island, pine of, 91 Nymplisca, 260, 168 400 INDEX 1. Omphalea, 365 Orchidex, 352 0 Origanum, 289 Ornithopusperpusillus, 121 Orobus sylvaticus, 130 Oxalis sensitiva, 172 Palmx, 382 Pandanus, 366, 288 Papilionacex, 341 Passiflora, 338 Periploca grxca, 357 Phleum pratense, 102 Phyllachne, 352 Pine-apple, 348 Pinus, 365 Pistacia Lentiscus, 270 Pistia, 339 Plane-tree, its buds, 119 Pomacex, 330 Populus dilatata, 157 Potamogeton, 260 Pothos, 360 Precis, 320 Primula marginata, 85 Pteris, 300 Rhapis, 25 1 Rhodiola, 368 Rivularia, 376 Rosacea:, 330 Rotacex, 320 Rubiaceac, 319, 219 Rumex sanguineus, 72 Rutacese, 235 Ruta graveolens, 254 Salix, 361 Salvia pomiferu, 270 Sarracenia, 146, 161 Scheuchzeria, 29 1 Scitamineae. 316 Scopolia, 358 Seriphium, 349 Silene inflata, 271 Sisyrinchium, 344 Smithia sensitiva, 343, 292" Solandra grandiflora, 123 Spergula, 281 Sprengelia, 292 Sterculia, 328 Stilago, 35 5 Strelitzia, 291 Strumpfia, 354 Stuartia, 90 Stylidium, 369 Tabasheer, 73 Tamarindus, 344. Taxus nucifera, 227 Thea, 347 Theobroma, 345 Tmesipteris, 300 Tournefortia, 290 Tragopogon major, 270 Tropseolum, 326 Tulbaghia, 211 Umbelliferae, 321 Uredo frumenti, 271 INDEX I. 40k Valisneria spiralis, 252 Vaucheria, 380 Ventenatia, 355 Viscum album, 170 Willows, 156 Xanthe, 369 Xylopia, 359 Yew, 227 Zostera, 360 CCC t «« ] INDEX II. INDEX TO THE EXPLANATIONS AND ILLUSTRATIONS TECHNICAL TERMS, &c. Abrupt leaves, 136 Abruptly pinnate leaves, 148 Abrupt root, 97 Absorption, 157 Acaulesplantx, 113 Acerosum folium, 132 Acid secretions, 71 Acinaciforme folium, 144 Acinus, 224 Acrimony, 77 Aculeus, 182 Acuminate leaf, 137 Acuminatum folium, 137 Acute leaf, 137 Acutum folium, 137 Adpressa folia, 127 Adscendens caulis, 106 Aqualis polygamia, 309, 347 Aggregate flowers, 243 Aggregati pedunculi, 116 Air vessels, 164 Ala, 238, 207 Alatus caulis, 110 Alatus petiolus, 117 Albumen, 230 Alburnum, 43 Algx,377 Alienatum folium, 145 Alkaline secretions, 72 Alterna folia, 125 Alterne ramosus caulis, 108 Alterne pinnatum folium, 149 Ament, 200 Amentacex, 364 Amentum, 200 Amplexicaulia folia, 129 Anceps caulis, 110 Anceps folium, 144 Angiocarpi fungi, 381 Angiospermia, 308, 336 AngulosuscauHs, 110 Annual roots, 94 Anther, 217 Anthera, 217 Aphylls plantx, 124 Apophysis, 373 INDEX II. 40S Apothecium, 378 Appendicuiatum folium, 146 Appendages of plants, 178 Apple, 223 Arillus, 234 Arista, 202 Arrow shaped leaf, 134 Articulatus caulis, 110 Articulatum folium, 147 Articulatus culmus, 114 Articulata radix, 101 Articulate pinnatum folium, 149 Artificial system, 279 Asperifoliae, 320 Atmosphere, 173 Astringent principle, 71 Auriculatum folium, 150 Avenium fol. 141 Awl shaped leaf, 143 Awn, 202 Axillaris pedunculus, 115 Bacca, 225 Bacillum, 378 Baik, 38 Barren flowers, 241 Basi trinerve fol. 142 Beak, 238 Beard, 202 Bell shaped corolla, 206 Berry, 225 Bicorncs, 327 Biennial roots, 94 Bifid leaf, 134 Biflori pednuculi, 116 Bigeminatum fol. 151 Bijugum fol. 150 Bilobum fol. 135 Bin a folia, 125 Binatum folium, 148 Bipinnatifidium fol. 136 Bipinnatum fol. 151 Biternatum fol. 151 Bitter secretion, 71 Blistery leaf, 140 Blunt leaf, 137 Border, 205 Brachiate stem, 109 Brachiatus caulis, 109 Bracte, 180 Bractea, 180 Buds, 119 Bulbiferous stem, 100 Bulbosa radix, 100 Bulbous root, 100 Bullatum fol. 140 Bunch, 193 Caducous, (falling early,) 179, 332 Calycanthemx, 325 Calyculatus calyx, 197 Calyptra, 203 Calyx 194—197 Cambium, 45 Campanulata corolla, 206 Canaliculatum fol. 143 Capitulum, 190 Capsule, 221 Capsula, 221 Carina, 207 404 INDEX If Carinatum folium, 144 Cartilagineum fol. 138 Caryophyllea, 327 Catkin, 200 Catulus, 200 Caqda, 238 Caudex, 95 Caulina folia, 125 Caulinu6 pedunculus, 115 Caulis, 105 Cellular integument, 36 Central vessels, 54 Channelled leaf, 143 Characters, 283 Ciliatum folium, 138 Ciliatum perianthium, 197 Cirrhifer petiolus, 117 Cirrhosum folium, 137 Cirrhose pinnatum, fol. 148 Cirrhus, 182 Classes, 303 Cl?sping leaves, 129 Clavus (Ergot) 271 Climbing stems, 107 Climbing petioles, 117 Cloven leaf, 134 Cluster, 187 Coccum, 222 Coloratum folium, 142 Columnifeix, 339 Coloured leaf, 142 Colours, 79 Coma, 238 Completus flos, 241 Composite folia, 150 Compound flowers, 242 Compressum folium, 143 Compressed leaf, 143 Compressus petiolus, 117 Concavum folium, 141 Concave leaf, 141 Conduplicatum folium, 140 Cone, 228 Conferta folia, 125 Coniferae, 365 Conjugatum folium, 150 Conjugate leaf, 150 Connata folia, 129 Connate leaves, 129 Conniventia stamina, 216 Contorts, 321 Corculum, 228 Cordate leaf, 133 Cordatum folium, 133 Coriaceum folium, 145 Coriaceous leaf, 145 Corolla, 205 Coronarisc, 323 Cortex, 38 Cortical glands, 165 Corymb, 189 Corymbus, 189 Costatum folium, 141 Cotyledons, 90, 229 Creeping root, 96 Creeping stem, 106 Crenatum folium, 139 Crenate leaf, 1 39 Crescent shaped leaf, 134 Crispum folium, 141 Cruciformis corolla, 25*llt 6-1