ne Pi STEED 25 39, 23 Ae sé Sra ness ah 7 . i . i 2 a } . een = Hai a ee ml 1 u bah at i Hi eh a ay = fii Uh ini a 4} Hd ead Hin} 513592 ii j i eETERSELEES: i HEE Hh } i j i) a) | Zz AH 1) ALi | eit isi pri Tm act gon fatetetate riety er a Rain i) wy 7 iit — aes Hy a a _ a - ay 7 Wh i i i HT i = | i 2 aii; p22 a i) Ha ce Hi ii) i ae i ih . _ ‘ Ves i i iH AY: bit F BOs tase at3 Es ie = 2 ieee piu aith is ais ~F, me zor | iy =o: 3986 = etetewt ate sacha neal ieManaies pak ay dap, Meg: van ag ce aces seal Fes Sh aot me, se bon ase? Fg HM 7 nes wld meh se Pe ie om : ras peer! Fosecterts ores! - sy Meningie i Hl He aN es RATURA! History JAN 3 7 394) Digitized by the Internet Archive in 2010 with funding from - University of Illinois Urbana-Champaign http://www.archive.org/details/ladiesbotanyofpr01 lind LADIES BOTANY: OR A FAMILIAR INTRODUCTION To the Study OF THE NATURAL SYSTEM OF BOTANY. BY JOHN LINDLEY, Pu.D. F.RS. ETC, ETC. ETC. PROFESSOR OF BOTANY IN UNIVERSITY COLLEGE, LONDON. Dich yerwirret, Geliebste, die tausendfaltige Mischung, Dieses Blumengewiihls tiber dem Garten umher ; Viele Namen horest du an, und immer verdranget Mit barbarischem Klang, einer den andern im Qhr. Alle Gestalten sind ahnlich, und keine gleichet der andern ; Und so dentet das Chor auf ein geheimes Gesetz, Auf ein heiliges Rathsel. O! konnt ich dir, liebliche Freundinn, Ueberliefern sogleich gliicklich das lisende Wort. —GérTHE. IN TWO VOLUMES.—VOL. I. FIFTH EDITION. QAP LONDON: JAMES RIDGWAY AND SONS, PICCADILLY. ver hall AN) Al yaniv i a, | - 530 4 Leas / vei INDEX CLASS I DICOTYLEDONS I THALAMIFLORAE Page Ranunculaceae I.5 Berberidaceae II.11 Nymphaeaceae 99 210 Papaveraceae I.19 Cruciferae 3.95 Resedaceae II.36 “Cistaceae oe 4 Violaceae I.64 -Droseraceae II.81 — Polygalaceae II.30 = Caryophyllaceae I.96 ~ Malvaceae 1.86 Hypericaceae 1.82 . Geraniaceae 1.36 ~ Linaceae II.129 Ly gs il.Caliciflorae- | Rhamnaceae II. 18 Leguminosae I.123 \ Rosaceae 1.107 ~ Ly thraceae II.66 _ Tamariscaceae >> 78 Onograceae I.46 sat Cucurbitaceae II.51 ~ Portulaceae 1.102 “s Crassulaceae IL.106 Grossulariaceae$Ribes) ,, 16 Saxifragaceae 93 112 Umbelliferae ; 1.26 XO III. COROLLIFLORAER Caprifoliaceae 1.175 Rubiaceae II.171 - Dipsacaceae +. oe >, Compositae I.199 Campanulaceae, I.170 Ericaceae I158 - 1116649 Plate I XXVI XLIX ore i oe o's «3 2 OTGo 22 33 4 OP eup Lok aX oat Cc : aNr.t ss onvowtfot tage . £0£.EE eseontduhH - ECL 2h eseosonecid — eer.t esi tesoqued- Ovr.t =—(i(s (ORO D BLUME GED” earl oseonokte ee P.I.166 Pi,XIII Bab.49 164 XIII Oléeacéae Gentianaceae BS 51 Polemoniaceae II 164 XLIII 52 Convolvulaceae I 161 Xii 53 Boraginaceae I 180 XV 54 Solanaceae I 185 XV55 Scrophulareacae I 194 XVI 57 Labiatae I 191 XVI 58 Primulaceae I 187 II 157 XLII 61 Plantaginaceae I 208 XVII 63 IV MONOCHLAMYDEAE PAGE PLATE BABINGTON Amaranthaceae I 133 IX 64 Chenopodiaceae II 143 XL 65 Poly goneaceae II 140 XL 66 Euphorbiaceae II 124 XXXVIII 72 Urticaceae I 148 XI 75 Amentiferae I 155 XI 78 ViGYMNOSPERMAE Conifere@ (Oak) I 138 x CLASS II MONOCOTYLEDQNS II FLORIDAE Orchidaceae I 223 XIX 83 Iridaceae I 219 XVIII 84 Amaryllidaceae I 216 XVIII 85 Alismgceae I 247 XXI 86 ' 29 II2206 XLIX Liliaceae I 231 XIX 88 (Asphoc 29 I 237 XX 9, (rulig) Melanthaceae I 239 89 Juncaceae I 241 xX 90 Typhaceae I 244 XXI 92 Araceae II 192 XLVI 93 Lemnaceae I 249 XXI 94 | . TIX ne HE aadaaet on nul | waite anbinlde i i Ut ALLINGIS Se Bis Mrthr o foal Ree eoasn i 7 a aS ssistiiaemA 4 Ee : a 1G III GLUMIFERAE 196 Pitcher Plants P1.L Mango 98 100 102 Cyperaceae Page I 262 P1.XXII Bab.97 Gramineae I 252 XXII CLASS ITiI CRYPTOGAMBAE Filices I 266 XXIII _Lycopodiaceae I 273 XXIII V6L.I (Page) VOL.I typ ‘ob 71 Passion Flower 92 Orange 130 Protea ana Marvel of Peru. 275 Moss 286 Jungermannia 282 Lichen 285 Mushroom 287 Sea-Weed 212 Distinction of Dicotyledon & Monocotyledon ‘VOL II VoL II 6 Magnolia 20 Vine 26 Pittosporum 40 Caper 44 Cactus 56 Begonia 60 Fig Marigold 87 Venus Fly Trap 98 Horse Chestnut 101 Walnut 1236 Rue 150 Mezereum 153 Cinnamon 161 Epacris 167 Trumpet Flower 179 Jasmine 182 Asclepis 188 Birthwort gti a towolt sotsesd IT . sesost OSI XTIXX TIIKx oon. > booW-se8 Fl G papsreny i SAARI 29° S88 EX eget sés I EAMLAOOTTYHD aoc I | sve f I ..0V rn = md be aH SAY BRSe s.® hey uh) i i (pespti liye ens A oil jin » . ory, tereves ] } sole fiutn . ony , a! iioth smiias TABLE OF CONTENTS. LETTER I. Page Introductory Remarks—Fundamental Terms—The Crowfoot Tribe—The Poppy Tribe : : ° : 6 ol LETTER II. The Umbelliferous Tribe—Blanching—The Geranium Tribe—Hybrid Plants 26 LETTER III. The Evening Primrose Tribe—The Myrtle Tribe : : . 46 LETTER IV. The Cruciferous Tribe—Double Flowers—The Violet Tribe 3 - bo LETTER V. The Passion-flower Tribe—Affinity—The Gourd Tribe—The Tutsan Tribe 71 LETTER VI. The Mallow Tribe—The Orange Tribe ; : . . 86 LETTER VII. The Chickweed Tribe— Metamorphoses of Plants—The Purslane Tribe— Succulent Plants——Breathing-pores . : : » 96 LETTER VIII. The Rose Tribe—Budding and Grafting—The Pea Tribe . 5 ley LETTER IX. The Protea Tribe—The Amaranth Tribe. ; 2 . 180 LETTER X. The Marvel of Peru Tribe—The Oak Tribe—Structure of Dicotyledonous Wood . ° : Z - : . 136 LETTER XI. The Nettle Tribe—Woody Fibre—The Breadfruit Tribe—The Willow Tribe 148 LETTER XII. The Heath Tribe—The Bindweed Tribe . : - . 158 Xvi TABLE OF CONTENTS. Page LETTER XIII. The Gentian Tribe—The Olive Tribe—The Jasmine Tribe . . 164 LETTER XIV. The Hare-bell Tribe—The Lobelia Tribe—The Honeysuckle Tribe—The Coffee Tribe . ° . : . . 170 LETTER XV. The Borage Tribe—The Nightshade Tribe—The Primrose Tribe. - 180 LETTER XVI. The Mint Tribe—The Foxglove Tribe & : ° - 191 LETTER XVII. Compound Flowers—The Ribgrass Tribe. 5 5 - 199 LETTER XVIII. Distinctions of Exogenous or Dicotyledonous, and of Endogenous or Mo- nocotyledonous Plants—The Narcissus Tribe—The Cornflag Tribe . 212 LETTER XIX. The Orchis Tribe—The Asphodel Tribe 3 : : . 222 LETTER XX. The Lily Tribe—The Colchicum Tribe—The Rush Tribe ‘ 5 Pasir LETTER XXI. The Bullrush Tribe—The Arrow-grass Tribe—The Duckweed Tribe . 244 LETTER XXII. Glumaceous Plants—The Grass Tribe—The Sedge Tribe ° . 252 LETTER XXIII. Cellular, Flowerless, or Cryptogamic Plants—The Fern Tribe—The Club- moss Tribe : : ° e 5 . 266 LETTER XXIV. The Moss Tribe—The Jungermannia Tribe . : + - 275 LETTER XXV. The Lichen Tribe—The Mushroom Tribe—The Seaweed Tribe . 282 Lis iseak ay; a) Cal oan 1 ae 4 A ) - 4 foals, aa’, an ~ Os i. ‘ e . / { s - Upright Yaa ois (SEO POND ES). s Nched- wath i Jb fi/s Y. q Mis Drake: ted. NALS wre | LETTERS ON BOTANY, &e. §e. LETTER I. INTRODUCTORY REMARKS—FUNDAMENTAL TERMS — | * THE CROWFOOT TRIBE—THE POPPY TRIBE. | (Plate I.) | You ask me how your children are to gain a know- ledge of Botany, and whether the difficulties which are said to accompany the study of this branch of science, cannot, by some little contrivance, be either removed altogether, or very much diminished.— Allow me, in answer to this question, to repeat a fable which I remember to have read in some French author. A lady, observing some ants travelling across a table, dropped a lump of sugar in the midst of them ; but, to her surprise, although ants are noted sugar- | eaters, they all retreated in terror from the spot, nor could any of them afterwards find courage to return to examine the object of their dread; on the con- trary, they chose another track, and carefully avoided that which would have proved a treasure had they known its value. Struck by the occurrence, the lady B 24 LETTER I. placed the same piece of sugar on a part of the table near which the ants were in the habit of crossing, and when she saw one of them approaching it, she gently placed her finger in his way, so as to obstruct his passage without alarming him; the ant paused, looked around him. and then took a new direction, not exactly towards the sugar, but near it; the lady again opposed his passage gently, and at last, by making him take a sort of zigzag direction, tacking, as it were, at every few steps, the ant was unconsciously brought to the sugar without being frightened. Once there, he examined the glittering rock attentively, touched it with his antenne, broke off a morsel, and hastened away with it to the ant- hill; whence he presently returned at the head of a host of his comrades, by whom the rest of the sugar was quickly carried off. So it is with science and the young who have to acquire a knowledge of it. Let them be once alarmed at the aspect of their new pursuit, and it is almost impossible to restore their confidence ; but there are few who, if led to it insensibly, will not perse- vere till they have made themselves masters of the subject. The most discouraging parts of Botany to a be- ginner, consist either in the numerous new and strange names one has to learn the meaning of, or in the minuteness of the parts by which plants are distin- guished from each other, or in the great multitude of species of which the vegetable kingdom consists ; and it must be confessed, that there is something seriously INTRODUCTORY REMARKS. 3 alarming in the mass of preliminary knowledge which it would appear has to be acquired before any per- ceptible progress can be made. But if we look at the subject a little more closely, we shall find that, of the technical names employed, only a small number is really necessary in the be- ginning; that minute parts are little consulted in practice, however much they may be in theory; and that in consequence of the perfect arrangements of Botanists, no more inconvenience is experienced from the number of species, than in any other branch of Natural History. There are certain terms, the exact meaning of which must be understood, and which cannot be dispensed with, if the science is to be studied to any good purpose; a sort of habit of observation has also to be acquired, without which the differences between one plant and another, can never be appreciated or remembered ; but these things may be gained imperceptibly and without any extraordinary exertion either of in- dustry or patience. We have only to begin with the beginning, and never to take one step till that which precedes it is secured ; afterwards, the student may advance to what point he pleases. ‘This appears to me to be the only secret in teaching Botany. We must, however, be careful while we attempt to strip the study of its difficulties, that we do not also divest it of its interest, and imitate those who, by the ingenious substitution of words for ideas, have contrived to convert one of the most curious and interesting of all sciences into a meagre and aimless system of names. BQ 4, LETTER If. Names are, no doubt, necessary for the purpose of dis- tinguishing one thing from another; but, as no one would call that man a carpenter, who only knew the names of all the instruments in a carpenter’s chest of tools, so neither can that person be considered a Bo- tanist, whose knowledge is confined to the application of a few hundred Latin names to flowers and weeds. Were the latter the mark of a Botanist, then would every gardener be so accounted, which would be a great and grievous mistake. « J’ai toujours cru,” said Rousseau, whom I would at once have adyised you to take as your guide, if his inimitable Letters were not both incomplete and obsolete, —‘*‘ J’ai toujours cru qu’on pourrait étre un tres grand Botaniste, sans connaitre une seule plante par son nom,”—and to a great extent he was right. Only to apply their names to a few plants, is a poor insipid study, scarcely worth the following; but to know the hidden structure of such curious objects, to be acquainted with the simgular manner in which the various actions of their lives are performed, and to learn by what certain signs their relationship, for they have their relations like ourselves, is indicated, is surely among the most rational and pleasing of pursuits. It is only by acquiring a knowledge of the natural system of Botany, that you can systematically provide yourself with such information. If timid, or unin- ered: or interested persons have alarmed you with an account of the difficulties of this mode of study, let me advise you to disbelieve them, and to give FUNDAMENTAL TERMS. 5 your little people the opportunity of making the at- tempt. With such assistance as I shall be happy to give you, I cannot doubt of their succeeding. You need not be told, that plants have generally five very distinct parts, viz. ROOT, STEM, LEAF, FLOWER, and rruir; the application of the three first of these terms, in their common acceptation, is already well known to you; the last is applied by Botanists, not only to such objects as apples, pears, cherries, and the like, but also to any part which contains the seed ; so that the grains of corn, the heads of the poppy, the nuts of the filbert, and even the little bodies which are commonly called caraways, are all diffe- rent kinds of fruit. These terms may pass without further explanation for the present. It is in the flower that the beauty of plants chiefly resides ; it is there that we find all the curious apparatus by means of which they are perpetuated, and it is the spot where the greatest number of parts are found, the names of which are unusual, and re- quire to be remembered. ‘To illustrate these let us take a very common plant, to be found in every meadow, by the learned called Ranunculus, by the vulgar Buttercup, or Crowfoot. On the outside of the flower of this plant, about the middle of its stalk, are one or two little leaves, which look like the other leaves, only they are a great deal smaller; indeed, they are so small as to resemble scales; these are the Bracts (Pl. I. 1. a. a.). Next them, and forming the external part of the flower itself, are five small greenish-yellow hairy 6 LETTER I. leaves (A. 6.), which are rather concaye, and fall off shortly after the flower opens ; leaves of this sort form the caLyx, and are called sepaLs; it is sup- posed that they are intended to protect the more tender parts of the flower, when the latter are very young and delicate. Next the sepals are placed five other leaves, which are much larger, and of a bright shining yel- low; they stand up and form a little cup, in the bottom of which the other parts of the flower are curiously arranged; these five shining yellow leaves form the coroixa, and are called prrats. They give all its gay and glittering appearance to the Crow- foot ; which, when they have dropped off, is scarcely to be distinguished from the grass it grows among. Their business is, in part, to prepare the honey which exudes from a little scale you will find on their in- side, near their base (jig. 1.), and, which, if secreted in sufficient quantity, is collected by bees for their’ sweet food; and it is, in part, to protect from injury the delicate organs which lie in their bosom. ‘These jast are of two sorts ; as you will soon learn. In a ring from which both the sepals and petals arise, you will find a number of little thread-like yellow bodies, which are thicker at the top than at the bottom ; they spread equally round the centre, as if they wished to avoid that part, and are a great deal shorter than the petals; we call them sTAaMENs. Their lower part, which looks like a thread, is called the FILAMENT ; their upper thickened end is named the anruer. ‘This last part is hollow, and will be FUNDAMENTAL TERMS. vf found, if you watch it, to discharge a small quantity of yellow powder, called the potten. ‘The pollen has a highly curious office to perform, as will be shewn you presently. Next to the stamens, and occupying the very centre of the flower, are a number of little green grains, which look almost like green scales ; they are collected in a heap, and are seated upon a small ele- vated receptacle (fig. 3.); we call the whole collection of them the pistrt, and each separate one a CARPEL, They are too small to be seen readily without a mag- nifying glass; butif they are examined in that way, you will remark that each is roundish at the bottom, and gradually contracted into a kind of short bent horn at the top; the rounded part (fig. 4. a.) is the ovary; the horn (d.) is the sryLe ; and the tip of the style (c.), which is rather more shining and somewhat wider than the style itself, is named the sTiGMA; so that a carpel consists of ovary, style, and stigma. At first sight, you may take the carpels to be solid, and fancy them to be young seeds: but, in both opinions, you would be mistaken. ‘The ovary of each carpel is hollow (fig. 5.); and contains a young seed called an ovute (fig. 5. d.), or little egg; so that the carpel, instead of being the seed, is the part that con- tains the seed. Although the ovule is really the young seed, yet it is not always certain that it will grow into a seed ; whether or not this happens, depends upon the pollen, of which we have already spoken, fallmg upon the stigma. If the pollen does fall on the stigma, it 8 LETTER) (1. sucks up the moisture it finds there, swells, and finally each of the minute grains, of which it con- sists, discharges a jet of matter upon the stigma, which fertilizes the ovule, and then the latter grows and becomes a seed. But if the pollen does not fall upon the stigma, then the ovule withers away, and no seed is produced. Thus, you see every one of these parts of the flower 1s formed for some wise purpose. ‘The sepals are to protect the petals ; the petals to protect the stamens and carpels, and to form sugary food for their support ; the stamens are to fertilize the ovules, and the carpels are to guard the young and tender seeds from injury; fertilization could not take place without the aid of the pollen; and the pollen could not produce its effect if it were not for the moisture and peculiar construction of the stigma. How admirable is the skill which is mani- fested in the construction of this little flower, and how striking a proof does it offer of the care with which the Creator has provided for the humblest of his works! You have now seen all the parts of which flowers usually consist; the fruit is merely an alteration of the carpels, and the seed of the ovules. So perfect is the adaptation of the several parts to the end they have to perform, that it rarely happens that in the Crowfoot any of the ovules miss being fertilized. For this reason, the fruit of the Crowfoot is almost ex- actly the same when ripe as when young, except that its parts are larger, and it has become brown, dry and hard (fig. 6.). Separate, at this period, one of FUNDAMENTAL TERMS. 9 the carpels from the remainder, and place it under the miscroscope ; it will be found to resemble a seed very much in appearance, and indeed is often called by that name; but you have already seen, from an examination of the carpel, that the real seed is hidden in its inside ; formerly fruits of this sort were called naked seeds; they are now called Grains; as for instance a grain of caraway, a grain of wheat, and so on. What remains to be seen of the structure of the Crowfoot is very minute, and requires some expert- ness in the use of a dissecting knife and microscope to be easily made out. It is not, perhaps, very im- portant that you should understand it; but, I may as well complete my account of the plant now that it is before us. I would recommend you to trust, at first, to the drawing that accompanies this; and not to waste your time in cutting up the grains, until you have well understood what it is you have to look for. The inside of the grain is filled up with the seed, now arrived at its perfect state; the shell of the carpel has become hard and thick, and not only effectually protects the seed from harm (fig. 8. a.) but keeps it in the dark; another wise provision, for without darkness the seed could not grow. ‘The shell thus altered is called pericarp. If you cut the seed through, you will, for a long time, discover nothing but a solid mass of white flesh, in which all the portions seem to be alike ; but if you happen to have divided it accurately from top to 10 LETTER I. bottom, cutting through both edges of the grain, as at fig. 8, you will then be able to discover near the base of the seed a very minute oval body (fig. 8. a.), which may be taken out of the flesh with the poimt of a needle. This oval body isa young plant; it is the part which grows when the seed germinates, and 1s named the EMBRyo; the fleshy matter that surrounds it, called ALBUMEN, is only intended to nourish the young and delicate embryo, when it first swells and breaks through the shell. Small as is the embryo, so small as to be invisible to the naked eye, it also is constructed in a regular manner. It is not merely an oval fleshy body, but it has two differently organized extremities, of which the one is divided into two lobes, called coryLepons (fig. 10.), or seed-leaves, and the other is undivided, and called rapicLe ; the latter is the beginning of a root, as the former were the begin- nings of leaves. Let the seed fall upon the earth, the embryo imbibes moisture, swells and shoots forth into a young plant, and thus the growth of the Ranunculus is renewed as soon as it is completed. Such is the structure of a perfect flower, and such the principal terms which you have to remember, in order to understand the language of Botanists; other terms there are, besides these, which are equally essential, but they are not used so frequently, and it is not worth detaining you about them now. I shall explain them whenever we meet with them. Having thus minutely examined the flower of the Crowfoot, let us next observe the way in which its other parts are formed. FUNDAMENTAL TERMS. 18) The roots of this plant consist of a number of little taper divisions, the points of which are very tender and easily bruised ; from near the ends of these little divisions, you have a number of delicate fibres, also with soft and tender points. It is by these points that the root obtains its watery food, from out of the soil; and if you break off the points the plant will languish until the wounds are healed, and new and perfect rootlets formed; if it is unable to renew them it will die. ‘This should always be thought of when you wish to transplant any thing; for the same cir- cumstance occurs in all other plants, and the success of removing shrubs, or flowers, or trees, depends very much upon the points of the roots being pre- served. In the gay Asiatic Ranunculus, which is so often cultivated by gardeners, for the sake of the gaudy colours of its beautiful double flowers, the roots at the time when they are taken out of the ground to be dried, have become so hard and tough, up to the very points, as not to be easily injured; yet it is pos- sible even in this case to prevent the plants from producing healthy leaves, and well-formed flowers another season, if the roots are carelessly mutilated when taken up. The Leaves are dark-green, and very much divided into lobes, which are narrower in the leaves near the top of the stem than in those near the root. The business of these little appendages of the stem is not merely to render the face of nature pleasing to the eye by the charming verdure they produce; nor, as in such plants as have eatable leaves, to supply men and 12 LETTER. I. animals with wholesome food. The plant itself could not grow without them; or, if it grew, could not bear fruit, but would totally perish as soon as it was born. ‘The business of the leaves is to suck out of the stem the watery food which the roots had sucked out of the soil, and the stem out of the roots ; and having filled themselves with it, to expose it to light and to air, to evaporate the superfluous part, and having thus in a manner digested it, to discharge it again back into the stem in the form of the peculiar matter which it may be the property of the plant to produce; such for instance as sugar in the Sugar Cane, flour in the Potatoe, gum in the Cherry Tree, a powerful medicinal substance in the Peruvian Bark tree, and poison in the Ranunculus itself. In order to enable the leaf to convey the watery food it sucks out of the stem to all parts of its own surface, and to return it back again, nature has furnished this little organ with a most curious and complicated arrange- ment of drains or conduits, consisting of excessively minute water-pipes glued together and branching in every direction ; these are what we call veins; which you see in the Ranunculus are all joimed together in the stalk of the leaf, but separate as soon as they enter the leaf itself, when they first divide into a few large arms, then subdivide into a number of smaller ones, and again divide over and over again until at last they form a net with meshes finer and more delicate than the most exquisitely manufactured lace. If you could examine the veins with a microscope you would find them still more curious in their structure than I have 2 THE CROWFOOT TRIBE. 15 represented them to be; for in the middle of every little vein is a sort of windpipe which conveys vital air to their extremest points. Such is the way in which the veins of the leaf are disposed in the Crowfoot. It is very essential that you should pay attention to this netted branching arrangement, because one of the great natural divi- sions of the vegetable kingdom is to be known by that circumstance. One of the great natural divisions of plants is called Exocenous, because the stems grow by addition to the outside of their woody centre ; the same division is also called DicoryLeponous, because the embryo has two seed-leaves or cotyledons. You may generally recognize such plants by their leaves having netted veins; so that you see it is neither necessary to watch the stem to see how it grows, nor to examine the seed under a microscope in order to count the cotyledons, if you would ascertain whether a plant is Exogenous or not; the manifest arrange- ment of the veins in the leaf reveals the secret struc- ture of the stem. If you have rightly understood what I have ex- plained thus far, you will not only have mastered several terms, but you will actually have made one important step in the study you have taken up: you will have become acquainted with the essential charac- ters of a large and important natural order of plants, called the Crowroor tripe (or Ranunculaces), among which are some that are remarkable for the virulent poison which often lurks beneath their beau- tiful exterior. The Crowfoot genus itself contains 14 LETTER I. some species, such as that called “the wicked” (Ra- nunculus sceleratus), and another called ‘the burn- ing” (R. acris), which will blister the skin if applied externally to the human body, or produce dangerous symptoms if taken into the stomach; these, however, are mild and harmless if compared with such as I shall presently mention to you. But first of all let us see in what the most essential character of the Crow- foot tribe consists. By far the greater part of the characters which we have seen that the Crowfoot possesses, will be also found in other and extremely different plants; but there are two characters which are what we call essen- tial: that is to say, such as will distinguish it and the other plants belonging to the same natural order, from other natural orders resembling it. These essential characters are, there being a great many stamens which arise from beneath the carpels, (which is what Botanists term being hypogynous, Pl. I. 1. fig. 3.); and also several carpels which are not joined together. If you will pay attention to these two circumstances, you will always know a Ranunculaceous plant, that is to say, a plant belong- ing to the Crowfoot tribe; and although you may not remember its name, you will know, what is of far more consequence, that it is, in all probability, a poisonous plant, and that its stem grows by addition to the outside of the woody centre, beneath the bark. A few instances of other genera, belonging to the same natural order, will put this in a clearer light. There is a little annual, with leaves cut into divi- THE CROWFOOT TRIBE. 15 sions as fine as hairs, and with small but rich dark scarlet flowers, called Adonis, or Pheasant’s eye. This plant agrees with the Crowfoot in its structure, in almost every point: but its petals have not a scale near their base, on which account Adonis is reckoned a plant of the same tribe, but is separated as a distinct genus. Another and charming little collection of pretty flowers is formed by the Anemones, with their purple, or white, or scarlet petals, which modestly hang their heads, as if unwilling to expose their beauty to every curious eye. ‘These have the calyx and corolla mixed together, so that you cannot distinguish the one from the other; and when their flowers are gone, they bear little tufts of feathery tails, or oval woolly heads, in the place of the clusters of grains which you found in the Ranunculus. Such tails or heads of wool, are collections of the grains of the Anemone, and contain the seeds; the tails themselves are no- thing but the styles of the carpels, grown large and hard and hairy; they are thought to be intended by nature as wings, upon which the grains may be car- ried by the wind from place to place. If you look at the leaves, or the stamens, or the young carpels, or the ripe seeds of the Anemone, you will find all those parts constructed, in every essential respect, like the Crowfoot. Hepaticas, which you have so often seen thriving, when neglected, in a cottage garden, when, perhaps, they perished under your own con- tinual care, as if they were created specially for the pleasure of the poor, are nothing but Anemones, with 16 LETTER I. three bracts underneath the flower, and either six or nine sepals and petals. You have seen the Globe-flowers (‘Trollius), with their yellow heads, in the borders among American plants; these have a great many sepals, which give the beauty to their flowers; their petals are little strap-shaped bodies lying on the outside of the stamens; and each of their carpels contains several seeds; in this they differ from the Crowfoots, but otherwise re- semble them so much, that before the flowers appear, you would take the Trollius for a Ranunculus. Marsh Marigold, again (Caltha), which grows in large green tufts in the meadows, and by the sides of ditches, differs from the Globe-flower in having no petals at all. Christmas Roses (Helleborus), and Winter Aconites (Eranthis), are also of the Crowfoot tribe ; each differing in one respect or other from those I have mentioned, but possessing the essential charac- ters already explained. All the plants yet mentioned, are so like the Ranunculus, that it is impossible to overlook their resemblance, even if it were not pointed out. But there are some others in which the resemblance is less striking at first, although it is equally great when understood. Who has not heard of Larkspurs? Rocket Larkspurs, with their spikes of white, and pink, and purple starry flowers; of Bee Larkspurs, which look as if the insect from which they take their name were glued to their inside; or Siberian Larkspurs, with their branches of blue flowers, which no gem nor mineral can emulate in brightness, or ~ THE CROWFOOT TRIBE. 17 deepness of colour? These are of the Crowfoot tribe, but less closely allied to Ranunculus itself, than what I have already mentioned. We are so accustomed to combine in our minds the idea of Buttercups and yellowness; that we are apt to overlook the resem- blance which really exists between the Ranunculus and the Larkspur, because of the want of yellow in the latter. But setting aside this, which is of no Bota- nical importance whatever, let us look at the calyx of the Larkspur (Delphinium). It is composed of five leaves, or sepals, the uppermost of which has a horn arising from out of its back ; so is that of Ranunculus, excepting the horn. It has four petals, of which two have long tails, hidden within the horn of the petal ; it is they which look like the bee’s body : Ranunculus has nothing of this, but five common petals instead. The Larkspur has a great many stamens arising from below the carpels; this is the first essential character of Ranunculus ; it has also several carpels (two or three) which are not grown together: and this is the second essential character of Ranunculus; so that this plant has, in reality, no essential character by which it can be distinguished from the Crowfoot tribe. As for its four strange petals, they are of no importance; for you will remark that in Trol- lius, the petals are little hollow bodies, and that the Marsh Marigold has none whatever ; so that not only the form of the petals is of no consequence in the Crowfoot tribe, but it does not even signify whether they are present at all or not. When you have once satisfied yourself that the é 18 LETTER I: Larkspur belongs to Ranunculacez, you will have no difficulty in perceiving that the true Aconite (Aconi- tum), is also of the same natural order ; for the re- semblance of these two is too striking to be mistaken. The true Aconite, which yields to no plant in the vi- rulent poison of its roots, has all the structure of the Larkspur, except that the upper leaf of its calyx has not any horn, but is very large, and resembles a sort of helmet, overshadowing all the other parts of the flower. In consequence of there being no horn to the upper leaf of the calyx, the two uppermost petals, which have horns, are forced to hide them be- neath the helmet, instead of inserting them into it. With these differences the Larkspur and the true Aconite are formed nearly alike. Peonies are the last plants I need mention, as be- longing to the Crowfoot tribe. They have a calyx which resembles green leaves, and which never drops off ; in other Ranunculacez, the calyx often drops off, even before the petals; im this respect, Peeonies are unlike the rest of the Crowfoot tribe; but they have the two essential marks of distinction in the carpels and the stamens. Let me recommend you to procure, if possible, all the plants that have thus been enumerated, and to compare them with one another till you fully under- stand their resemblance, which you may very readily do; and then you will find, that to know the struc- ture of the common Crowfoot, is, indeed, as I said in the beginning, te know the properties and general character of a large natural order. THE POPPY TRIBE. 19 The next plants I would advise you to study, are the Poppies; that singular genus, which, in the form of a few red flowered species, is the plague of the care- less farmer, who calls them Redweed, and, in the form of another, is rendered, by the folly and vice of man, the scourge of half the world, in the shape of opium. The Poppies form a genus of plants re- presenting the characters of a small natural order, very nearly related to the Crowfoot tribe, from which it differs in its properties, being of a stupifying, in- stead of a burning and blistering nature, as well as in its botanical characters. Like the Crowfoot, the Poppy has leaves with netted veins, and also a great many stamens, arising from under the carpels; but, unlike the Crowfoot, the carpels are not several, and distinct from each other, but have all grown together into a single ovary (Pl. I. 2. fig. 2.); the styles are wanting; and the stigmas are elevated hairy lines, which spread equally from the top of the ovary, forming a sort of star-like crown. If you open the ovary, you will find that it consists of but one cell, or cavity; and that several little plates, which project from the sides of it into the cavity (fig. 6.), are covered with very numerous and very small ovules, or young seeds. In course of time, the ovary changes to a hollow box, with a hard brittle shell, called a capsuLx, which is the fruit: and when it has become of a pale brownish colour, it, and the seeds it contains, are ripe; in this state it is the poppy-head you see in the windows of druggists’ shops. So hard is the shell of the capsule, and so c2 20) LETTER I. small are the seeds, that the latter would never be able to get out unless nature had contrived some certain manner of opening the box. Lid it has none, for the hardened stigmas bind down the top and prevent its opening: but in order to remove this im- pediment, a number of little valves open underneath the edges of the stigma (fig. 5. a.), and through these the seeds fall out. You see then, that the Poppy differs from the Ra- nunculus, in haying the carpels united into an undi- vided ovary, instead of being all separate ; in the same way all the Poppy tribe differ from all the Crowfoot tribe ; but this is not all. Ifyou break the stem or leaf of a poppy, there runs out a milky fluid, in which the stupifying principle of the plant is contained; no milk is found in the Crowfoot tribe, the juice of which is always watery and transparent. This is another and most important mark of distinction. The most essential differences between the Crow- foot tribe, and the Poppy tribe, therefore, stand ianse—— Crowfoot Tribe, or Ranunculacee. Stamens very numerous. Carpels distinct. Juice watery. Poppy Tribe, or Papaveracee. Stamens very numerous. Carpels united into one central ovary, with a single cavity. Juice milky. Besides these marks, by which you may know the two natural orders, there are others. The Poppy has two sepals, and twice two petals; this is never THE POPPY TRIBE. Q] found in the Crowfoot tribe; but as some of the Poppy tribe have three sepals, and twice three petals, the number of those parts is not sufficiently constant to form an essential mark. Having thus examined the flowers, and ascertained what the differences and resemblances are between the one tribe and the other, I would next advise you to compare the leaves of wild Poppies with those of the Crowfoots, and you cannot fail to be struck with their great resemblance ; and thus will you have become acquainted with two striking natural orders, neither of which will you ever be likely, I should hope, to forget. For the sake, however, of impressing the characters of the Poppy tribe more strongly upon your mind, I should advise you to take a few more examples ; especially as the fruit by which the Poppy tribe is partly known, frequently seems, until it has been carefully explained, to be very unlike the only instance we have, as yet, examined. On the sea-shore near Brighton, and indeed on most parts of the English coast, there grows a blue- leaved plant, which looks as if the salt of the sea spray had encrusted itself upon its skin; but which is sure to be remarked when in flower, because of its large bright yellow flowers, and when in fruit by the long stiff horns it bears in the place of a poppy head ; for this last reason it is called the Horned Poppy (Glaucium). This plant also belongs to the Poppy tribe. It differs from the Poppy itself, in its fruit being very long and slender, instead of short and 29 LETTER I. round; but like that plant it contains only one cavity. The reason why the poppy head is so thick, is, that it is formed out of as many carpels grown together, as there are stigmas; in the naked-stalked Poppy there are seven; in the Opium Poppy (Papaver somniferum) there are a great many; in others more and in others less: but m the Horned Poppy the fruit is formed of only two carpels grown together, which will at once explain why the fruit is so narrow. Celandine (Chelidonium majus), a pale green cut- leaved plant, with little yellow flowers, found in groves and in shady lanes, or in churchyards, by no means uncommonly, is another plant belonging to the Poppy tribe. Its milk is of an orange colour, and has a nauseous taste; its fruit is a long pod constructed like that of the Horned Poppy, but when it is ripe dropping into two pieces called vALVEs. The Argemone or Prickly Poppy, and the Esch- scholtzia, so very remarkable for its finely cut bluish leaves, and bright yellow flowers, are also of this natural order. In the Eschscholtzia a circum. - stance happens which you should not omit to note, because it seems to explain in other plants several things which appear at first sight very puzzling. The flower of this species before it expands is enclosed in a taper-pointed green sheath, shaped like a hutkin, which is pushed off by degrees as the petals unfold, and at last drops to the ground. What is this singular part, which is so unlike any thing im the plants hitherto examined? it is the calyx, which, like that THE POPPY TRIBE. 25 of the Poppy is formed of two sepals; these sepals grow so firmly together by their edges, where they touch each other, that when the time for them to fall off arrives, they are unable to separate; but as it is ab- solutely indispensable to the plant that the calyx should in some way or other be got rid of, in order to enable the flower to expand, nature has provided the calyx with the means of separating from the stalk by its base; and thus it is pushed off in the manner I have mentioned. ‘This, which is the first instance you have yet seen, of two parts that stand next to each other having grown together, is an exceedingly common occurrence in plants, and is one of the means by which the real nature of flowers is frequently so masqued that one can hardly discover how it is they are formed. I would advise you to recollect this occurrence, and in good time you will see how it explains other things. This letter will have found occupation enough for your little girls in beginning their Botany, without my carrying the subject further for the present. EXPLANATION OF PLATE I. 1. Tue Crowroor Trise.—A. A twig of the upper part of the stem of the Upright Meadow Crowfoot ; aa bracts, 6 calyx.—l. A petal seen in the inside with the scale at the base.—2* An anther with a part of the filament seen in front ; 2** the same more mag- nified, viewed sidewise.—3. The centre of a flower cut through, the calyx and corolla being removed ; the stamens are seen spreading outwards, with their filaments originating from underneath the Q4 carpels ; the latter occupy the centre, and are shewn to arise from a short conical central part, which is their receptacle.—4. One of the carpels; a@ the ovarium ; 4 the style; ¢ the stigma.—d. The same carpel cut open so as to shew the young seed, or ovule, ¢.— 6. A cluster of ripe carpels, or grains.—7. One of the grains sepa- rate ; compare this with fig. 4, on the opposite side of the plate. -- 8. The same grain cut in half, shewing @ the young plant or em- bryo, and 4 albumen or nutritive matter stored up for feeding the young plant when it begins to grow.—9. Is an embryo extracted from the albumen and seen from the back.—10. The same seen from the side, so as to shew the two minute seed-leaves or cotyle- dons, a. (N.B. The principal part of these figures is more or less magnified.) 2. THE Popry Tripe.—A. A flower and leaf of the naked-stemmed Poppy, the flower of which is turned so as to exhibit the four petals, the stamens, and the ovary; the natural size.—1. Is a flower-bud, with the two sepals by which it is covered.—2. An ovary, with its diverging star-like stigmas.—3. The same part cut through from top to bottom, with the ovules or young seeds exposed.—4. A stamen, with the filament and anther.—5. A capsule, or head, when ripe ; the little valves by which the seeds fall out are seen at a.— 6. The capsule cut across, so as to shew the plates which project from its shell into the cavity, and the multitude of seeds that grow upon the plates.—7. A seed.—8. The same cut through; a the albumen ; 4 the young plant, or embryo. LIBRARY QF THE _ UNIVERSITY OF ILLINOIS hh OY Yn Umble tout ys ee ; 3 ¥ ce FE Lae Z CVMVIVMNAL DI?) LETTER II. THE UMBELLIFEROUS TRIBE—BLANCHING—THE GERA- NIUM TRIBE—SPIRAL VESSELS—HYBRID PLANTS. weer. ncn (Plate II.) en nn rene You ask me whether the Strawberry is not a plant of the Crowfoot tribe; and if so, how it happens that it is so wholesome a fruit. It is true that the Straw- berry plant has, in many respects, a resemblance to the Crowfoot, especially in its numerous stamens and carpels; and I, therefore, am not surprised at your thinking that they must both belong to the same natural order. But when you are more accus- tomed to the making accurate observations, you will cease to be deceived by such resemblances. On a future occasion I shall introduce the Strawberry and its relations to your notice (see Letter VIII.) ; for the present I shall content myself with calling your attention to a difference by which they may be readily distinguished. ‘The Crowfoot is, as you have seen, a plant with the stamens arising from underneath the carpels, so that when the calyx drops, or is taken off, the stamens still remain surrounding the car- pels, and are, as Botanists say, hypogynous (see p- 14.). But in the Strawberry flower you cannot tear off the calyx, without bringing the stamens 20 LETTER Il. away along with it; the stamens therefore arise out of the calyx, which is a very different affair from what occurs in the Crowfoot, and in this way they, and the natural orders to which they respectively belong, may be certainly known from each other. When stamens have such an origin as in the Straw- berry, they are technically called perigynous, a term which is so commonly used, that I could wish you to remember it. Let me now shew you a natural order of plants, which, although less beautiful than the Poppy tribe and the Crowfoot tribe, is not less interesting or important. Enclosed with this letter are fresh gathered specimens of a little plant with dark-green leaves, cut into many fine divisions, like parsley- leaves; their smell is strong and unpleasant. ‘The flower-stem of this weed is about a foot high, and it bears small greenish-white blossoms, arranged at the ends of the branches in a very peculiar manner (Pl. Il. 1. fig. 1.). From its resemblance to Parsley, and from its noxious qualities, for it is very poisonous, the vulgar call it Fool’s Parsley (Aithusa Cynapium). You will: find it growing wild in almost any piece of waste garden ground, where it has sometimes been mistaken for Parsley that has sprung up sponta- neously, and has proved fatal to unfortunate children who have eaten of its leaves. As it is rather a dangerous neighbour, you will not be sorry that I have taken an early opportunity of shewing you how to know the traitor, notwith- standing his resemblance to one of the most harmless THE UMBELLIFEROUS TRIBE. a7 of plants. Look at the way in which the flowers are arranged. You will remark that the flower-stem divides at the top into a number of short slender branches, whieh all proceed from a common point, just as the rays of a parasol all proceed from the ring which slides up the stick; this is called an uMBEL. Lach of these rays is terminated by a cluster of flowers, the stalks of which also proceed from a common point, and form again an umbel. So that the Fool’s Parsley not only has its flowers arranged in umbels, but in what, in consequence of their divided nature, are called compound umbels; the clusters of flower-stalks by which the branches of the first set of rays are terminated, are called simple umbels, by way of distinction. It is to this circum- stance of the peculiar arrangement of the flowers, that the natural order to which the Fool’s Parsley belongs is called Umbelliferous, or Umbel-bearers ; for all the other plants belonging to the order, have their flowers arranged in a similar manner ; and thus you have one exceedingly simple and manifest cha- racter by which the order is known. Let us next look at a separate flower ; the parts are very small, but your little people’s eyes are, I dare say, good enough for them to see all that I think it necessary to point out, without the use of a microscope. In the first place, there is scarcely any sign of a calyx; all that you can find is a little narrow border, from within which the petals arise. The petals are five in number (fig. 2.), of a greenish- white colour, and each has its point doubled inwards 98 LETTER if. (fig. 3.), in such a way as to look like the spots ina suit of hearts in playing-cards; there are only five stamens, and they arise from between the petals. The centre of the little flower is occupied by a whitish fleshy body, which is divided into two lobes, from the top of each of which springs a style (fig. 5.). Where now is the ovary? Is it the whitish fleshy body from out of which the styles arise ? if so, young seeds must be found in the inside of that part; but if you cut it, you will find neither cavity nor young seed. The ovary is in this plant so concealed, that a beginner would not be likely to find it without assist- ance. Look at the top of the flower-stalk, on the outside of the petals; you will find a thickish deep- green furrowed part (fig. 5.a.), from the top of which the petals and stamens spring; and if you cut that part across you will discern two little cavities, in each of which hangs a young seed. ‘This then is the ovary, which in Umbelliferous plants seems placed below the calyx and the corolla, on which account it is called inferior, just as in the Crowfoot and Poppy tribes, in which it stands above the calyx and corolla, it is termed superior. These terms, like many others used in Botanical books, were invented long since, when Botany was in a rude state, and they convey an incorrect notion of the true nature of the parts to which they are ap- plied. I shall, therefore, digress a little, to explain to you the real nature of the difference between a superior and an inferior ovary. In plants, such as the Crowfoot, which have a superior ovary, the THE UMBELLIFEROUS TRIBE. QQ sepals, the petals, the stamens, and the pistils, grow separate from each other ; but in umbelliferous plants, whose ovary is inferior, the principal part of the calyx, the stalks of the petals, and the lower half of the filaments, grow to the sides of the ovary so firmly that they cannot be separated, and hence the ovary looks as if it grew beneath the other parts ; while, in reality, the parts of the flower, both of the Crowfoot and Fool’s Parsley spring from the top of the flower-stalk, beneath the pistil ; but in the former, they are all separate; while in the latter, they grow all together. After the petals and stamens have fallen off, the ovary gradually increases in size; the furrows on its surface become deeper; it hardens, acquires a dull brown colour, and, at last, a fruit (fig. 6.) is formed, which, in time, separates into two halves (fig. 7. a. b.), or grains; which are what are vulgarly and in- accurately named seeds. These are the principal peculiarities in the flowers of umbelliferous plants; and they will always serve to know them by. You may, if you wish it, render their characters more simple and more easy to re- member, by taking the essential distinction of um- belliferous plants to consist in flowers growing in umbels, and inferior fruit, which when ripe separates, or may be separated, into two grains. The appearance of this order is, however, so peculiar, that I have no fear of its being recognised with certainty after you have seen a few more instances of it. Let us now return to the means of distinguishing 30 LETTER II. Fool’s Parsley from common Parsley. Observe, once more, the simple umbels of the former species; at the bottom of the flower-stalks there are a few narrow taper-pointed green leaves which you will, pro- bably, recognize by their situations to be bracts (see page 5. and fig. 1. a. a. a.). When bracts sur- round a number of flowers in aring, just as sepals surround petals, and petals surround stamens, they form what is called an INvoLUCRE; it is, therefore, by this name that I must speak of the bracts of um- belliferous plants. The involucres, then, of Fool’s Parsley, consist each of three leaves, which all turn one way, spreading towards the outside of the umbel ; by this easy character it may be certainly known from common Parsley, and from all the rest of our wild umbelliferous plants, the involucres of which are quite different. It would be a good thing if they could all be dis- tinguished from each other as easily; but, unfortu- nately, umbelliferous plants are often so much alike, that nothing but a very minute attention to the for- mation of the fruit, will enable you to find out their names and qualities with certaimty. I shall not pre- tend to shew you much of the manner of doing this ; for, if you would learn to distinguish them, you must peruse books on systematic Botany, im which umbelliferous plants are described. But, as it will be useful for you to know the meaning of some words that are, of necessity, employed in speaking of their fruit, I may as well explain what those are. The back of each half of the fruit of Fool’s Parsley, THE UMBELLIFEROUS TRIBE. 31 has four deep furrows (vallecule) which cause five elevated ridges to appear (fig. 10. a.); the nature of these furrows and ridges is very much attended to. The faces of the halves of the fruit, where they touched each other before they were separated, are also noticed; they are called the commissure. In the skin of the seed, underneath the rind of the fruit, you will often see very minute slender brown lines (fig. 10. and 9. b.), which, if highly magnified, are found to be bags filled with oil; they are called stripes, or witfe, and it is in them that the substance which gives so pleasant a flavour to caraways and coriander grains, is stored up. You may, perhaps, have a difficulty in finding the stripes; if so, cut a ripe grain across (fig. 10.), and you will see the ends of the stripes (fig. 10. b.) looking like little mouths, out of which a dark oily matter slightly oozes ; or if you are still unsuccessful in your search, then make a thin slice in the same direction, place it in water under the microscope, and throw light upon it from beneath, by means of the mirror, and the ends of the stripes will appear as so many holes. There are few tribes of plants more familiar to us than the umbelliferous, because of the many useful species that it contains. ‘The carrot, the parsnep, celery, eryngo, angelica, lovage, caraway, cori- ander, dill, anise, hemlock, fennel, and samphire, are all well known kinds; besides which there is a host of others with which the Botanist is acquainted. I should advise you to desire the gardener to find you specimens of all those I have mentioned, and, 32 LETTER II. on learning the distinctions of them, to compare them with each other, and with the descriptions of Botanists, before you attempt to attend to the wild species; in that way you will familiarise yourself a little with the manner in which the characters are drawn up; a very necessary qualification for every one who would study umbelliferous plants like a Botanist. The greater part of the species has white or whitish flowers: a good many, as the fennel for example, have yellow flowers, and a very few blue ones. ‘To the latter class belong most of the species of Eryngo, and the beautiful Didiscus coeruleus (Bot. Register, fig. 1225.), which, although a native of New Holland, forms so charming a hardy ornament of the flower garden in the summer. It is not a common circumstance for a tribe so very similar in the structure of the species as um- belliferous plants, to contain both poisonous and wholesome kinds; but here we have the Deadly Hemlock and Dropwort, associated with Parsley, Carrots and Fennel; and what seems still more re- markable, a species, Celery, which is unwholesome in its wild state, become harmless when cultivated. Common Celery is a native of the meadows of many parts of England, where it forms a rank weedy strong-smelling herb, which is unfit for human food ; how different it is mm gardens every body knows. It is thought that its ceasing to be noxious when culti- vated is owing to the greater part of its stems and leaves being blanched. No doubt you must be Oc BLANCHING. 33 curious to know why blanching a plant should destroy its unwholesomeness, and therefore we will again digress from our principal subject for the purpose of explaining this curious fact. In my last letter, I told you that the business of leaves is to expose to light and air the sap they suck out of the stem. ‘The consequence of light and air acting upon the surface of leaves, is the forming in their substance, which is originally of the same yellowish-white that you see in seeds, a green colour, which is more or less deep in proportion to the degree in which the light is powerful; thus a plant which stands exposed to the sun all day long, has its leaves of a darker green than another which grows among other trees, or near a building which throws it into the shade for a part of the day: and the latter again is darker green than a plant which grows at the north side of a high wall, or in an enclosed court which the sun’s rays never enter. In like manner, if you cause a plant or any part of a plant to grow in total darkness, it will be entirely desti- tute of greenness; or in other words, the substance of the plant will remain of its original yellowish- white, because no green matter can be formed but by the action of light; and if a part already green is kept for a long time in darkness, it will be- come yellowish-white, in consequence of all its green bemg destroyed by the peculiar action of the atmo- sphere upon plants in darkness.—This is the explana- tion of blanching. But mere loss of colour is not the only consequence of plants being kept in the dark ; D 34 LETTER II. you have already been told that poisons, when it is the nature of plants to yield poisons, are also formed in leaves by the action of light; the absence of this wonderful agent will therefore prevent the formation of poison, as well as the formation of green colour ; and hence blanching renders poisonous plants harm- less. ‘Thus, in the Celery, but a small portion only of the leaves is exposed to light; the whole of the stem and of the lower part of the leaves is buried in the earth ; the small quantity of noxious matter that might be formed by the few leaves which are allowed to bask m the sun, has to pass down the buried stalks of the leaves before it can reach the stem, where it would be laid up; but you know the leaf- stalk of the Celery is very long, and any thing which has to filter from the upper part of such a leaf to its bottom has to take a long journey, in the course of which it is constantly under the destroying influ- ence of darkness; so that before it can reach the stem, it will all have perished. A _ similar effect is produced by the Italians upon Fennel, which, although not a poisonous plant, has too powerful a taste to be a pleasant food, except as an ingredient for flavouring sauces. The Italians, in their warm climate, cause Fennel to grow rapidly in darkness, and thus obtain it in a state very like Celery in appearance; the darkness destroys the principal part of the flavour, no more of the Fennel taste being left than is sufficient to give the blanched stems a pleasant aromatic quality, There are no plants which you are likely to mis- THE _-UMBELLIFEROUS TRIBE. 55 take for umbelliferous, if you will only attend to the exact nature of the characters I have already explained. Nevertheless, as it is exceedingly diffi- cult for begimners to comprehend the necessity of exactness in natural history, and as you have already been puzzled about the Strawberry and the Crowfoot, I may as well caution you against an error which you may fall into; and I cannot do better than point it out in the words of Rousseau himself. “If you should happen, after reading my letter, to walk out and find an Elder-bush in flower, I am almost sure that at first sight you would exclaim; here we have an umbelliferous plant. You would find a large umbel, a small umbel, little white blossoms, an in- ferior ovary, and five stamens; yes, it must be an umbelliferous plant. But let us look again; suppose I take a flower. In the first place, instead of five petals, I find a corolla, with five divisions, it is true, but nevertheless with all five joined into one piece ; now flowers of umbelliferous plants are not so con- structed. Here indeed are five stamens, but I see no styles: I see three stigmas more often than two; and three grains more often than two; but umbel- liferous plants have never either more or less than two stigmas, nor more nor less than two grains to each flower. Besides, the fruit of the Elder is a juicy berry, while that of umbelliferous plants is dry and hard. ‘The Elder, therefore, is not an umbel- liferous plant. If you now go back a little, and look more attentively at the way in which the flowers are disposed, you will also find their arrangement D 2 36 LETTER II. only in appearance like that of umbelliferous plants. The first rays, instead of setting off exactly from the same centre, arise some a little higher, and some a little lower; the little rays originate with still less regularity ; there is nothing like the invariable order you find in umbelliferous plants. In fact, the ar- rangement of the flowers of the Elder is in a cyme, and not in an umbel. See how mistakes will some- times lead us to the discovery of truth.” You must not suppose from so much having been said about the umbel, that that kind of arrangement of flowers, always indicates an umbelliferous plant ; on the contrary it is only when the umbels bear infe- rior fruits separating into two grains that they really belong to plants of this natural order. ‘There are many other plants which bear umbels, with a different structure of the flower, as for instance the Geranium tribe (Plate II. 2.). Many species of that natural order have simple umbels, but the structure of their flowers is exceedingly different. Suppose I fill up my letter with some account of them; if you are weary of study for the moment, you can leave off at the point at which we have now arrived, and resume the subject on another day. Do you know what a Geranium is? if you ask the gardener for one, he will bring you a neat-looking shrubby green-house plant, with fragrant leaves and upright umbels of beautiful red flowers ; this however is not a Geranium, although it is nearly related to one, and belongs to the Geranium tribe; it is a Pelargo- nium. ‘The real Geraniums are little herbs which THE GERANIUM TRIBE. 37 grow by the way side, or in waste places, or in the meadows, and some of which are often cultivated in the borders of the flower-garden or shrubbery, for the sake of their gay red or white or purple blossoms. One of them, the Meadow Geranium, is so very common that vou can scarcely fail to procure it; if you should fail, then almost any other kind will do as well for the purpose of enabling you to follow me. This plant has roundish leaves, divided into several deep lobes, with the veins branching in the manner of Exogenous plants (p. 13.), a circumstance which also occurred in the umbelliferous order, although I forgot to mention it. The leaves are placed upon long hairy stalks which are singularly swollen at the base, where there grows a pair of pale thin green scales called strputes; these parts you have not before seen; they are frequently not met with in any species of a whole natural order, but when they do occur they usually accompany the leaves of every plant in the order; their use is unknown. ‘The flowers of this species can hardiy be said to be in an umbel, for only two of them grow together, but if more were to appear, as is the case in other species, they would all diverge from one common centre; and this you know would make an umbel. ‘Their calyx consists of five ribbed sepals which spread when the flower is open, and when the petals have fallen off contract round the young and tender ovaries, to which they form an efficient protection. ‘The petals are five, of a purplish blue colour; they are very round at their ends, and spread in such a manner as to form a 58 LETTER Il. figure something resembling a saucer ; their veins are unusually prominent, and give the petals a streaked or pencilled appearance. We did not see any veins in the petals of the Crowfoots, or the Poppies, or the Umbelliferous plants, and yet we might have found them if we had paid attention, for veins are as regularly found in petals as in leaves, and, what is very curious, they have the same structure, except that they are usually composed of air-vessels only. ‘The tough and flexible tubes, or water-pipes, which you find surrounding the air-vessels in the veins of leaves (p. 12.), are in those organs indispensable for the protection of the air-ves- sels, and for giving strength to the leaf, during the many months which it has to exist; but all this won- derful provision against injury, would be thrown away in the petals, which never live beyond a few days, sometimes only a few hours ; and would be prejudicial to that delicate and transparent appearance in them which we so much admire. Nature, therefore, who creates nothing in vain, has generally formed petals with veins composed of air-vessels only ; and hence the extreme delicacy of the fragile corolla. The petals of the Geranium are so well adapted to shew you this arrangement, and you must be so curious to witness the way in which the secret workings of vegetation take place, that I am sure you will thank me for teaching you how you can best view the structure. For this purpose place the petal of a Geranium upon a piece of perfectly smooth and flat glass, such as is usually furnished for the transparent stage of a SPIRAL VESSELS. 39 microscope ; wet it with water; and then lay over it another flat piece of glass. Press the two glasses firmly together, and by degrees you will squeeze all the air out of the petal, and it will become transparent. You may then, with a pretty good magnifying power, observe all the air-vessels of the veins distinctly, looking like fine threads of silver wire twisted up like a spiral spring. It is on account of this appear- ance that the air-vessels are called technically sprra VESSELS. The stamens (fig. 2.) are ten, arising from beneath the pistil; that is, they are hypogynous; they are placed in two rows, each of which consists of five sta- mens. The lower part of the filament is broad, and rather convex ; it curves a little towards the pistil, and then tapers off into the part which bears the anther. The pistil (fig. 3.) has a very singular appearance. At the base it has five roundish projections, covered all over with clammy hairs; from the top of these projections a sort of column arises, which at the point is five-lobed (fig. 4.); the projections are the ovaries, the column is composed of five styles glued together, and the five lobes are the stigmas. ‘The hairs upon the ovaries will give you a good idea of the nature of hairs in other plants. Cut off, with a sharp knife, a very minute portion of the skin of one of the ovaries, and lay the morsel on its side in water under the microscope; you will find that the hairs are delicate transparent projections, tapering to a point. Some of them are very short and 40 LETTER II. curved downwards, as if it was their business to protect the surface of the ovary (fig. 11.), others stand erect, and have a head of a brownish colour, from which a clammy fluid exudes; the last are secreting hairs, and their duty is supposed to consist in carrying off the volatile matter to which the plant owes it smell; for they are not only found on the ovaries, but on almost all the other parts. When the fruit (fig. 6.) is ripe, it resembles, in a striking manner, the bill of certain birds; on which account the Geranium is called, in English, Cranes- bill, by which I would have introduced it to you, if the Latin name had not become the more common. This singular appearance is owing to a very simple circumstance. In most plants the styles shrmk up, or fall off, at the same time that the flower fades, and by the time the fruit is ripe, have entirely disap- peared. But in the Geranium, the styles continue to grow and harden as fast as the fruit itself; and when the latter is ripe, the styles project from the ovaries in the form of a beak. At the time when the fruit is ripe the seeds are shut up in the cavities of the ovary, so that one would wonder how they are to get out; if you would wish to catch the Geranium in the act of sowing its seed, gather a little branch of the ripe fruit in a fine summer’s morning, before the dew is off it, and put it in the sun. By degrees the fruits will dry, and if you watch them, you will be surprised by some of them, on a sudden, emitting a snapping sound, and you may see first one and then others of the ovaries THE GERANIUM TRIBE. 41 quickly curving upwards towards the top of the style, opening, at the same time, by their face, so as to let their seed drop out (fig. 6. a.). This is caused by the styles contracting from dryness, and shortening ; they stick so close together at their points, that they cannot separate there, and so they actually pull the ovary up by the roots, and then roll up upon themselves, as if they were frightened at what they had done. ‘The seeds are often beautiful objects, and are sometimes curiously pitted or netted all over their surface. No workman ever gave such finishing to the setting of the most costly gems, as Nature has given even to the seeds of a weed. Among our wild flowers are two genera which belong to the Geranium tribe ; the Geranium itself, and the Storksbill (Krodium). The latter is very common in gravelly and sandy wastes, and looks so like a Geranium, that you will, most likely, mistake it for one. You may, however, know it by five only of its ten stamens bearing anthers. In the Geranium you will find that the five outermost of the stamens, are much shorter than those which form the inner row, and more stunted (jig. 2.), but they all have anthers. In the Storksbill the five outer are still more stunted, and have no anthers. But the most interesting part of the tribe is that which is cultivated in green-houses, and to which J have already said the name Pelargonium is applied. This differs from both the other genera in the stamens being more than five, and fewer than ten in number, and in the co- rolla being irregular, that is to say, different in dif- 42 LETTER Il. ferent parts; the two upper petals are larger than the three lower, and stand altogether apart, so as to give the flower the appearance of having two lips. These Pelargoniums are almost entirely natives of the Cape of Good Hope, and have become as much the favourites of modern florists, as the tulip, the pink, the ranunculus, and the auricula were of their forefathers. And yet they were not originally so very beautiful; their leaves indeed were always fragrant and their colours gay, but they possessed nothing like the clearness of complexion, the regular features, and the rich variety of colour which characterise the present race. To what are we to attribute this sudden change? To cultivation? No doubt to cul- tivation; but to cultivation of a very peculiar kind, of which our ancestors never dreamed; we call it HYBRIDIZING. You are already acquainted with the singular causes which bring about the change of ovules into seeds (see page 8.); and you know, that if the pollen does not act upon the stigma, the ovules shrivel up and die prematurely. It has been discovered, that if two plants are very near relations, the pollen of one will act upon the stigma of the other, just as well as if the pollen was produced by the anthers of the plant to which the stigma belongs; but when the seeds so obtained are sown, they change to plants which are not exactly like either of those from the intermixture of which they sprang, but which bear a strong re- semblance to both. For instance, if you take the pollen of a plant with blue flowers, and place it upon 2 HYBRID PLANTS. 45 the stigma of one which has red flowers, the seed will produce a plant having purple flowers; or, if a plant with a very vigorous mode of growth is thus inter- mixed with another of a very dwarf habit, the plants which spring from seeds thus procured, will be neither very dwarf nor very tall; and soon. This is the secret of the improvement of Pelargoniums, which happen to intermix very easily: a sort with large ugly flowers, is intermixed with one with small neat flowers, and you have, in all probability, a variety with large flowers, that are as neat in appearance as those of the small flowered kind. I need not parti- cularize, with more minuteness, the way in which plants respectively influence each other; a little reflection must render it apparent to you, now that you understand the principle. I must not, however, omit to tell you, that intermixture can only take place between plants very closely related to each other, and that distant relations have no influence the one on the other. You could not hybridize a Ge- ranium with a Pelargonium, nor those Pelargoniums which have fleshy tumours for stems with such as have slender stems, nor even a gooseberry with a currant ; but to the power of intermixing the slender stemmed real Pelargoniums there seems to be no limit. That nature acted thus, long before man discovered her secret, there can be no doubt; for winds and in- sects are as skilful hybridizers as we are; and the different races of apples, pears, and other fruit, which have, in all ages, sprung up in gardens, are, no doubt, indebted for their origin to such circum- 44, LETTER II. stances; but it is only in modern times that this mode of proceeding has been reduced within certain rules, and that hybridizing has become a fixed and useful art. EXPLANATION OF PLATE II. I. Toe UmBetuirerous Tripe.—l. A portion of the flowering stem of Fool’s Parsley, shewing the umbel; aaa the one-sided in- volucres by which the plant is especially known.—2. A flower mag- nified, shewing the petals, stamens, styles, and disk.—3. A petal separated from the rest, with its curious incurved point.—4. A stamen, with the filament and anther.—5. A young ovary seen from the side ; a the ovary itself; 4 the styles; c the line where the calyx is to be sought for.—6. A ripe fruit viewed from its side; at the base, a forked axis is just perceptible, from the arms of which the grains finally swing.—7. The fruit with its grains separated, and swingmg from the arms of the axis.—8. A back view of one of the grains; the five prominent ridges are distinctly visible-—9. The face or com- missure of the same grain; 6 one of the stripes or vittee——10. The same grain cut through; a@ the ridges; } the stripes; ¢ the albumen.— 11. Half a seed taken out of the rind of the gram: @ the embryo, lying at the upper end of a large quantity of albumen.—12. The embryo very highly magnified, and seen sideways for the sake of . shewing its two seed-leaves, or cotyledons. Il. Toe Geranium Trise.—l. A couple of flowers of Meadow Geranium, one of which has dropped its petals; a bracts.—2. The ten stamens and the style-—3. The lower part of a pistil, covered with glandular hairs.—4. The top of the style and the five stigmas.— 5. The lower part of a pistil spht, to shew a the ovule, and 4 a tapering axis, to which the styles are glued. It is this part which forms the hard centre of the beak in the ripe fruit, and from which the styles drop, after they have curled up to shed the seeds.—6. A couple of ripe fruit, one of which is beginning to shed its seed; a an ovary from which the seed has dropped.—7. A seed; a the 45 hilum, or scar left by its separating from the ovary.—8. Seed split ; the embryo /is curiously rolled up, and plaited, and there is no albumen; @ is the radicle, or seed-root; 5 the cotyledons, or seed- leaves.—9. Is a cross section of the same seed.—l0. The embryo in its natural state, with the skin of the seed stripped off; the radicle is a taper body, hooked back at the narrow end of the embryo.— 11. Hairs very highly magnified; the short sharp-poimted ones are lymphatic hairs; the long upright pin-headed ones are secreting hairs. LETTER III. THE EVENING PRIMROSE TRIBE—THE MYRTLE TRIBE. wore rerrece. (Plate IIT.) oer. aed My last letter was so long that I fear you must consider me unreasonable in expecting you to be already prepared for another. And yet I think that considering the interest you say your little girls take in plants, I shall scarcely do wrong in profiting by - the present opportunity of going on with the subject, especially as this letter is likely to be much shorter than the last. They already begin to wonder where the terrible difficulties lie concealed, with which you have hitherto been frightened from allowing them to study Botany ; but I can venture to assure them that, as far as the elementary parts of the science are con- cerned, there are no difficulties to encounter greater than what they have already overcome. I feel per- fectly sure that Crowfoots, and Poppies, and Umbel- bearing plants, and Geraniums, are now familiar to you, together with all their relations. We will next take a family of quite another kind. In the meadows and woods of Europe, North America, and the colder parts of Asia, are found a great number of herbs which, with a great accor- She Evening. ee tose. tle: LET | fie rag - V4 A) : ' Dprubly OVEWMATGY — Lez mtoat. * Ve My ae OS LZ 2. | IF Lem P71! 10 LIBRARY ° OF THE MIVERSITY QF ILLINGIS THE EVENING PRIMROSE TRIBE. 47 dance in their general appearance, agree also in this remarkable circumstance, that every one of the parts of the flower consists either of four pieces or of some number which may be divided by four; in South America are many species of a similar nature, only they are shrubs and are much more richly coloured. Botanists call these Onagracee, or the Evening Prim- rose tribe, because the charming yellow flower which unfolds its bosom to the evening sun, and drinks up the dews of night with its petals, rendering darkness as lovely as noon-day, but which retires at the ap- proach of the sun, rolling up its petals and carefully protecting its stamens and pistils from the glare of light, is one of the tribe; it might be called the owl of the vegetable world, only it is more beautiful and delicate than that hard-hearted enemy of mice. If you have ever examined one of them accurately you will be at no loss to recognize all the rest. For this purpose suppose you take the Shrubby Evening Primrose (Osnothera fruticosa), a beautiful little North American plant, with an absurd name, for it is not a shrub. The leaves of this plant are of a narrow figure, not unlike the head of a lance, and their veins are dis- posed in a netted manner like all the preceding ; it has therefore a stem which mereases in size by addition of matter to the outside of the wood; or in a word it is Exogenous; the leaves do not grow opposite each other from opposite sides of the stem, but are placed one a little above the other, so as to be alternate ; mark this. 48 LETTER IIi. The flowers are bright yellow; and are entirely different from those of any of the preceding tribes. In the first place the calyx has a long slender tube (Plate III. I. fig. 1. a.), from the top of which arise two leaves, both turned the same way, and notched at the point (fig. 1. 6.) ; itis in reality composed of four sepals, united at the base into a tube, but capable of being separated above the tube into four pieces, as you may easily see if you attempt to divide it with the point of a pin. From the top of the tube of the calyx arise four petals.—Observe, again,—four,—which are of a bright yellow, and are rolled together, except in the night, when the flowers are expanded. Twice four stamens spring from the top of the tube ; each has a very long anther, which swings by its middle from the summit of the filament, and sheds its pollen in such a way that it looks as if it were mixed with cobweb. If you magnify this pollen in a drop of water, each grain will be found three-cornered (fig. 5.), and held to its neighbour by excessively delicate threads; a peculiarity in the pollen which is rarely met with, except in the Evening Primrose tribe. The ovary (fig. 1. c.) is inferior, and is marked by eight ribs, of which four are more prominent than the others; it contains four cavities, in each of which is a great many seeds. The style is a long slender body, rising within the tube of the calyx, as high as the stamens, and then separating into four narrow stigmas. THE EVENING PRIMROSE TRIBE. 49 The fruit is a dry oval case, with four angles, opening into four pieces, called vatves (fig. 6.). Thus, you see all the parts of this plant, from its calyx to its fruit, consist either of four, or twice four parts; the like happens in all the genuine species of the same natural order ; by which character they are easily known. There are many plants of very diffe- rent orders, that have four sepals, or four petals, or some of their other parts of that number; but it is only in the Evening Primrose tribe that all the parts are in fours at the same time; or some multiple of four, which is botanically the same thing. There are no Evening Primroses, really wild, in Great Britain, however frequent they may be in gar- dens. But there is an exceedingly common wild flower, called Willow-herb (Epilobium), one of the species of which, called the ‘ great hairy,” is, perhaps, the most noble of all our British herbs. Its stout shaggy stems grow five or six feet high, and are terminated by long clusters of bright red flowers. If you were to compare it with the description of the Evening Primrose, you would think it really must be a species of that genus, only the flowers are not yellow. This, however, is not the only difference. When the fruit of the Willow-herb is ripe, it sheds seeds which are furnished with a curious apparatus to enable them to fly about, and spread themselves over the land; each of them has a very long tuft of silk at one end, which is so light, that the smallest breeze is sufficient to buoy it up, and raise it aloft into the air, there to be caught and carried to a great distance. E 5O EETPTERGI(: Nothing of this sort is found in the Evening Prim- rose. Another plant, of far greater beauty than either of the foregoing, is the Fuchsia, an American genus, for which no English name has been contrived, and which is now one of the greatest of all the foreign ornaments with which our gardens are embellished in the sum- mer and autumn. Every body has Fuchsias; the poor weaver grows them in his window; many an industrious cottager shews them as the pride of the little plot of ground before his door; and even the suburban inhabitants of London itself, speak of the beautiful Fuchsias they rear, with enthusiasm and delight. You must, therefore, know very well what the Fuchsia plant is. Examine its flowers; on the outside of all, you have a deep crimson covering, divided into four firm sharp-pointed leaves; this is the calyx. Rolled up within it, and closely em- bracing the stamens, are four little dark purple leaves, which are not half so long as the calyx; they are the petals. The other parts you will easily recognise. But the fruit is not a hard dry case, or capsule, bursting into four valves when it is ripe; it contains four cavities indeed; but its rind is deep purple, fleshy and juicy ; ina word, it isa berry. ‘This, then, is a marked distinction from other plants of the Evening Primrose tribe; but, as in all other respects the Fuchsia agrees with them, it is not accounted suffi- ciently different to belong to any other natural order. The Evening Primrose tribe has little, except its beauty, to render it imteresting to mankind; for THE MYRTLE TRIBE. 5) | there is not a single species which possesses any useful property worth mentioning. Remember, that num- ber four, throughout all the parts of the flower, is its character; and you will be in no danger of either forgetting it, or mistaking it. I have already said that other orders have, occa- sionally, four parts of the calyx, or corolla, or of some other class of organs, and yet do not belong to the Evening Primrose tribe. 1 will give you an instance of this. You know what a Myrtle is. Takea sprig of that beautiful, but delicate evergreen, for your next sub- ject. It has hard shining deep-green leaves, which do not drop off when winter comes; but seem as if they were intended to make us forget that winter has power over vegetation; the stand opposite each other, and if you bruise them, emit a fragrant aromatic odour. If you hold them against the light, you will see them look as if pierced with holes, closed up by a green transparent substance; they are not, how- ever, pierced: but the appearance is owing to their containing a vast number of little transparent cells, in which the aromatic matter, to which they owe their fragrance, is laid up (Plate III. 1. fig. 10.). The flowers have a calyx of five divisions; there are five petals of a dazzling white; and from the sides of the calyx, there arises, in a ring, a very con- siderable number of slender white filaments, tipped by little roundish anthers (fig. 2.). The ovary, which is inferior, contains three cells, and a good many ovules; from its flat top springs E 2 52 LETTER Vim. one style (fig. 2.), which ends in a stigma, so small that it cannot be discovered without a microscope (fig. 4.). The fruit of the Myrtle is a purple berry, so like a Fuchsia berry on the outside that you might mis- take the one for the other; but it has only three cells, instead of four, and has a strong aromatic taste, of which the Fuchsia is entirely destitute. You will, after reading this, ask me, perhaps, with surprise, what resemblance [ can discover between the Myrtle and the Evening Primrose tribe; for it seems difficult to select two objects more unlike. I although the Myrtle itself is not very like an Evening Primrose, yet there are many of the answer thus Myrtle tribe, which, having only four divisions of the calyx, and four petals, might be mistaken for plants belonging to the Evening Primrose tribe, for they have an inferior berry, like that of a Fuchsia; you would however see that the number four could not be traced further than the petals, and conse- quently, the resemblance would cease with these parts. The Myrtle tribe, like the last natural order, abounds in beautiful plants; it also contains many that are of great use. The spice you call Cloves, con- sists of the young flower-buds of a tree found in the East Indies (Caryophyllus aromaticus) ; and Adlspice is the berries of a West Indian species (Myrtus Pi- menta.) The pleasantfruits called the Rose Apple, and the Jamrosade, in the Kast Indies, are produced by dif- ferent kinds of Eugenia; Guava Jelly is prepared from the succulent berries of trees of the Myrtle Tribe, found THE MYRTLE TRIBE. 5a in the West Indies; and, finally, the Pomegranate is an example of another fruit-bearing kind, which has migrated from Barbary into Europe. All these are trees with berries for their fruit; and they form the greatest part of the tribe. Others how- ever there are which have dry fruits opening at the top, and containing a great number of very minute seeds ; these, the principal part of which are natives of New Holland, have very often also alternate leaves. It is therefore neither to the fruit nor to the position of the leaves upon the stem, that you are to look for the precise character of the Myrtle tribe. The infe- rior ovary, the numerous stamens, the single style, and the dotted leaves, are what you will know it by with most certainty. To that division of the tribe in which the fruit is dry and many-seeded belong Melaleuca and Metrosideros, with their long tassels of silken stamens, purple, or yel- low, or crimson; and so dothe gigantic Gum Trees of New Holland (Eucalyptus). These last are remarkable for having no petals ; and for their calyx falling off like a lid or extinguisher. I told you, m my first letter, to observe what I said about the curious calyx of Eschscholtzia, which was pushed off by the petals in the form of a hutkin, in consequence of the sepals not being capable of separating in the usual way. So is it with the Eucalyptus; its calyx has all its parts soldered together, as it were, into a hard fleshy lid; when it is time for the stamens to unfold, they push the calyx so forcibly, that it breaks away by its base and drops off, leaving the stamens at liberty to ex- pand as fully as may be necessary. EXPLANATION OF PLATE III. 1. Toe EventnG Primrose Trise.—l. A flower of the Shrubby Evening Primrose half unfolded ; a the tube of the calyx ; 4 the divi- sions of the calyx ; c the ovary.—2. The same flower deprived of its petals, and with itssepals divided from each other, shewing the stamens and stigma.—3. The tube of the calyx cut open ; at the top are seen the bases of the eight stamens that spring out of it.—4. A stamen.— 5. A cluster of pollen grains, with the threads by which they are held together ; represented as they are seen when immersed in water.— 6. A ripe fruit, with the four openings at the top, through which the seeds escape.—7. The ovary cut through, before it is ripe; it exhibits the four cells, and the numerous seeds in them.—8. One of the valves of the fruit separated from the others, with the seeds sticking to it. —9. A seed.—10. An embryo, from which the seed-coat has been stripped ; it is not surrounded by albumen, but is protected only by the skin of the seed. II. Toe Myrrie Trise.—l. A flower of the Common Myrtle, much magnified.—2. The same cut perpendicularly, shewing two of the cells of the ovary, and the origin of the style and stamens.—2*. A cross section of the same.—3. Another with part of a filament. —4. The tip of the style and stigma.—5. A ripe fruit.—6. The same cut across, with the curved embryo seen lying within it, with- out any albumen.—9. A leaf.—10. A portion of a leaf magnified, shewing the transparent dots in it. — : as * a . : “ _ << j= |. LIBRARY << 22> OF THE | ‘ UNIVERSITY OF ILLINOIS be f . Fr 2 -f qr She C1r0ucifcr0ottd Lbe, : Y a Wea Gedas on LETTER IV. THE CRUCIFEROUS TRIBE—DOUBLE FLOWERS—THE VIOLET TRIBE—METHOD OF ANALYSIS. i oead anne aamatemaamamendamaad (Plate IV.) wens nan I am pleased, but not surprised, to find from your last letter, that Botany dees not prove, upon exami- nation, to be either so dry and technical a science as you imagined, or so little related to objects of daily interest, as others had persuaded you. Depend upon this truth, before all others, that knowledge is always useful, and that when we are unable to discover its utility, we have to blame our own short-sightedness, or incapacity, or any other cause, rather than know- ledge itself. Sir John Herschel, in that admirable treatise of his which should be in the hands of every human being who has arrived at an age to be capable of under- standing it,—Sir John Herschel has well remarked that, ‘* the question to what practical end and advan- tage do your researches tend? is one which the spe- culative philosopher, who loves knowledge for its own sake, and enjoys, as a rational being should enjoy, the mere contemplation of harmonious and mutually dependent truths, can seldom hear without a sense of humiliation. He feels that there is a lofty 56 LETTER IV. and disinterested pleasure in his speculations which ought to exempt them from such questioning ; com- municating as they do, to his own mind the purest happiness (after the exercise of the benevolent and moral feelings), of which nature is susceptible, and tending to the injury of no one; he might surely allege this as a sufficient and direct reply to those who, having themselves little capacity, and less re- lish for intellectual pursuits, are constantly repeating upon him this inquiry. But if he can bring himself to descend from this high but fair ground, and justify himself, his pursuits, and his pleasures in the eyes of those around him, he has only to point to the history of all science, where speculations, apparently the most unprofitable, have almost invariably been those from which the greatest practical applications have emanated. What, for instance, could be apparently more unprofitable than the dry speculations of the ancient geometers on the properties of the conic sections, or than the dreams of Kepler (as they would naturally appear to his contemporaries) about the numerical harmonies of the universe. Yet these are the steps by which we have risen to a knowledge of the elliptic motions of the planets, and the law of gravitation, with all its splendid theoretical conse- quences, and its inestimable practical results. The ridicule attached to ‘ Swing-swangs’ in Hooke’s time did not prevent him from reviving the proposal of the pendulum as a standard of measure, since so ad- mirably wrought into practice by the genius and per- severance of Captain Kater ;—nor did that which UTILITY OF BOTANY. 57 Boyle encountered in his researches on the elasticity and pressure of the air, act as any obstacle to the train of discovery which terminated in the steam- engine. The dreams of the alchemists led them on in the path of experiment, and drew attention to the wonders of chemistry, while they brought their advo- cates (it must be admitted) to merited contempt and ruin. But in this case it was moral dereliction which gave to ridicule a weight and power not ne- cessarily or naturally belonging to it: but among the alchemists were men of superior minds, who reasoned while they worked, and who, not content to grope always in the dark, and blunder on their subject, sought carefully in the observed nature of their agents for guides in their pursuits ;— to these we owe the creation of experimental philosophy.” It perhaps would not have been amiss to have begun this correspondence with the quotation I have just made ; but I was anxious that a little interest should be awakened in the subject before any thing like a formal defence of its utility should be under- taken by me. If I were disposed to add any Bota- nical instance of important results arising from ap- parently trifling causes, it would be easy enough to do so. Tor instance, the microscopical investigations by Grew of the nature and properties of the little cells and bladders that are found beneath the skin of plants, were the forerunners of all the valuable train of physiological discoveries, by which the productive- ness of the soil has been so much increased ; the cu- rious but neglected inquiries of Kolreuter into the 58 LETTER IV. possibility of intermixing the races of plants, laid the foundation of modern improvements in the qua- lities of cultivated species ; while the ingenious but derided speculations of Camerarius upon the relation that exists between the properties and structure of species, have put the physician in possession of a power of discovering the hidden uses of plants, the limits to the application of which no one can foresee. It is mentioned, that in the voyage of Lord Anson round the world, when new and unknown lands were constantly discovered, the dread which his surgeon entertained of the effect of strange herbs was so great that, from fear of poisoning the crew, he would some- times permit them to use no other kind of fresh ve- getable food than grass. At the present day there should be no navy surgeon who would not be able to point out at once, in every place, an abundance of plants, the use of which could not by possibility be at- tended by any ill effects. You have already seen that the Crowfoot tribe consists of burning and blistering species, that the Poppy tribe produces stupefaction, the Umbelliferous tribe is chiefly aromatic, but not always to be trusted, Geraniums astringent, Evening Primroses insipid, and Myrtles fragrant and aromatic. Another example of the uniform prevalence of pe- culiar properties in the same tribe or natural order, is afforded by Cruciferous plants. The healthy stimulating effects of Mustard and Cress, and the nutritive properties of ‘Turnips and Cabbages are well known to every body. These THE CRUCIFEROUS TRIBE. 59 plants belong to an extensive tribe called Cruciferous, or Cross-bearers, because their four petals are placed in such a way as to resemble in some degree a Mal- tese cross. Unfortunately for those who have little power of observation, and less patience, their flowers are usually very small; but I am convinced that this circumstance will be far from deterring my young friends from attempting their study; it will rather operate as an incentive to their making themselves acquainted with them. They are already, I suspect, familiar with a mean- looking weed, called Shepherd’s Purse (Capsella Bursa pastoris), which is found every where at all seasons of the year, except the severest part of the winter. Its name was given it because it has a number of pouches filled with very small seeds, which you might fancy were fairy coms. Let us look at it botanically. Its leaves are veined in that netted manner which indicates the Exogenous structure ; and consequently you know that if it were ever to form a woody stem, its woody matter would be arranged in concentric circles. The form of the leaves is like that of an ancient arrow head, sitting closely to the stem, and extended downwards at the base into a sharp barb on either side (Plate IV. 1.). The flowers are arranged regularly upon a central stalk in the form of a raceme ; and, what is extremely singular, they are uniformly destitute of bracts. “This is so unusual a case that I do not remember any other instance in the whole vegetable kingdom in which bracts are so constantly absent; the absence of 60 LETTER IV. these little leaves is hence a mark of the Cruciferous tribe. Observe, I pray you, how very useful it is to be aware of this. Imagine yourself cast away upon a desert island; and there, surrounded by plants of unknown forms and tempting looks, none of which you dare use from fear of their proving poisonous. Among them however you remark a good many of the same kind, one of which is just beginning to bear its tufts of flowers: the blossoms are too young to be examined, but old enough to shew you that they grow without bracts ; the leaves you would easily see were those of Exogenous plants, and you would immediately know that this species at least would be not only harmless, but the very best kind of vegetable for you to consume ; a salad which might be eaten with the utmost con- fidence. But it is not thus alone that Cruciferous plants may be recognised. The structure of their flowers is of a very peculiar kind. ‘The calyx is formed of four little leaves or sepals; within which are four very small white petals, arranged in the manner which I have already stated gave rise to the appellation of Cross- bearers (fig. 1.). | Within the petals are six stamens (fig. 2.), of which two are a very little shorter and more spreading than the other four. To this cha- racter no parallel is to be found in any other than Cruciferous plants, and consequently it is a second essential character, by which they are to be known. The pistil is an oval green body, shaped something like a wedge, on the summit of which is a little cushion of a stigma seated on an exceedingly short THE CRUCIFEROUS TRIBE. 61 style (fig. 2.). If you cut open the ovary you will find (fig. 3.) that it contains two cells, in each of which is a number of young seeds or ovules hanging by slender thread-like stalks, The fruit (fig. 6.) becomes a wedge-shaped flat body, composed of three pieces, two of which (fig. 6. a. a.), the valves, separate from the third (fig. 6. b.), which is named the partition or DISSEPIMENT (fig. 8.); it 1s to the edges of this third piece that the seeds stick by little threads (fig. 7.). In the inside of these seeds the embryo is bent double, after a singular fashion (fig. 10.), the seed-root being pressed close to the back of the seed-leaves. This has been rather a wearisome lesson, to one so little accustomed to the use of the microscope, to which you must already have had recourse several times; but you have now the satisfaction of knowing that you possess the secret of recognizing with cer- tainty nearly a thousand species, scattered over the face of the world, all of which are harmless, and many highly useful. What would the farmer do without Turnips and Rape, which are Cruciferous plants? or the gardener without Cabbages, Sea-Kail, Mustard, Cress, and Radishes ? or how could the florist supply the place of his Wall-flowers and Stocks? All these are such common plants, that you can have no difficulty in procuring specimens for examination; you will find that while they are all unlike in trifling circum- stances, they agree in having their parts arranged exactly in the same manner as the Shepherd’s Purse ; 62 LETTER IV. but you will remark a difference in their fruit, of this nature ; in some of them, as the Shepherd’s Purse itself, the pod is so very short, that there is not much difference between its length and breadth; im others, it is very long and slender, as in the Turnip and Cabbage; to the former of these fruits the name of Silicle is given; to the latter, that of Silique; and by many Botanists the whole tribe of Cruciferous plants is divided into two portions, of which one is called Siliculose, and the other Siliquose. By the more scientific Botanist of the present day, this distinction is held in less estimation, and new divisions, founded upon the structure of the embryo, are employed ; but these are so obscure, that [ will not fatigue you with them. The most beautiful species in the whole tribe are the Wall-flower, which sheds its sweetest odours over the ruined buildings of England, and the Stock, that, with its hoary leaves and gay flowers, gives an air of green old age to the rocks and cliffs of the Mediterranean. Both these, however lovely in their wild and single state, are chiefly cultivated when their flowers have become what is called double; that is to say, when the parts which are usually sta- mens, and pistils, and sepals, are all transformed into petals; by which means the quantity of gaily coloured parts is much augmented. There are those who, with an air of scientific delicacy, pretend to despise these beautiful objects, and call them mon- sters; but I would not have you follow such an example; for, in reality, double flowers, imdepen- > DOUBLE FLOWERS. 638 dently of their acknowledged beauty, afford the most important evidence of the true nature of the different parts of the floral system, as you may one day know. To you, as to many others, it may be a subject of wonder how these double flowers are increased, for if the stamens and pistils are converted into petals, it would seem that no means are left for multiplying the race. ‘This would, doubtless, be so, if all the sta- mens and pistils were really thus transformed ; but among many flowers, some are found in which a per- fect stamen or two remain; and others, in which a perfect pistil or two can be found. If the stigmas of the latter are touched with the pollen of the former, ovules are fertilized, and seeds produced, which will grow into other plants, the flowers of which will be as double as those of their parents. No one knows why double flowers should be capable of being thus perpetuated; it seems as if any tendency which is once given to a plant, may be carried on from genera- tion to generation, by a careful attention to the stop- page of all disposition to depart from the new cha- racter: in the Stock any plant that produces flowers less double than usual, must have a tendency to de- part from the double state, and, therefore, should not be allowed to bear seed, or to influence the seeds borne by other plants, but should be carefully era- dicated as soon as its flowers are sufficiently ex- panded for their true character to be ascertained. By attention to such rules, Turnip-rooted and Long- rooted, White, and Scarlet, and Purple Radishes, and all the different races of Turnips, have been pre- 64: LETTER IV. served for years ; whereas, if great precautions to maintain them in their purity had not been constantly taken, they would long since have become thrown together, and reconverted into the wild form from which they sprang. I take it for granted, you are so much interested in the pretty flowers of your garden, that you would be sorry to see all the double ones turn single ;—you will now be able to avert such a sad catastrophe. Candy tuft (Iberis), sweet Alyssum, the snowy Arabis of spring, that pretty little tufted purple thmg which is named after the French flower-painter Aubriet (Aubrietia deltoidea), Honesty with its clusters of broad bucklers, the modest Whitlow-grass (Krophila verna), which springs up on the crest of every wall, the earliest harbinger of spring, Watercresses, Horse Radish, and a host of others, will be furnished either by the garden, or the fields, to augment your acquaintance with this natural order. Leaving it now, as requiring no further explanation, we will next proceed to another spring tribe. Violets, sweet Violets, and Pansies or Heartsease, represent a small family (Pl. IV. 2.), with the struc- ture of which you should be familiar; more, how- ever, for the sake of its singularity, than for its extent or importance ; for the family is a very small one, and there are but few species belonging to it in which much interest is taken. As the parts of the Hearts- ease are larger than those of the Violet, let us select the former in preference, for the subject of our study. The Heartsease is a little herbaceous plant, as you THE VIOLET TRIBE. 65 know, with leaves cut, as you suppose, into several deep divisions ; here, however, you are mistaken. The true leaf is a narrow oblong blade, with netted veins, rather notched at its edge, and tapering gra- dually into a stalk (fig. A.a.); it is not slashed or divided at all. But on each side of the leaf, quite at the bottom of its stalk, there is a deeply- cut stalkless part, which is of the same colour as the leaf, but shorter (fig. A. b. b.); this is a sti- pule (see page 37), and it is that which gives the lobed and lacerated appearance to the leaf. Here you have an exemplification of the care with which you ought to look at plants if you would understand their construction rightly ; it may be true indeed, as theoretical Botanists say, that stipules are only little leaves, but it does not follow that on that account we may call them leaves; for it is quite clear that what- ever their theoretical similarity may be, they are stationed by nature in a particular place, in a particu- lar form, for some good purpose or other. You will some day know that the sepals of the calyx, and the petals of the corolla, and the stamens, and the carpels, are all leaves in different states; but you must not on that account cease to distinguish them carefully, and call them by their right names, when you find them fixed by nature in the form of sepals, petals, stamens and carpels. Our own foot is a sort of hand, and our toes are fingers ; but we cannot on that account dispense in practice with the use of the words feet and toes. The flowers consist of five sepals of a narrow F 66 LETTER Iv. figure and extended in a singular manner at the base ; of these some are much larger than the others. The corolla is formed of five petals, which are also of unequal size; two of them, which are differently coloured, stand erect and rather above the others ; a third, standing in front of the rest, has a short horn or spur at its base. Then we have the stamens, also five in number, of a singularly irregular form (fig. 1.); two of them, which are in front of the others, have long tails, which are hidden within the horn of the front petal ; the other three have no tail, nor any particular irre- gularity of figure, but they are all terminated by a broad membrane of a rounded form (figs. 2. 3. a. a.), and bordered by a fringe of hairs; filaments there are none. The pistil is a superior roundish pale-green body (fig. 5.), terminated by a short fleshy style, which is shaped like a narrow funnel, or a taper inverted cone; at the top (figs. 7. 8.) it is of a bright green, nearly spherical, slightly hairy, and hollow, with a hole on one side, to which there is a minute lip; through this hole there is access to the stigma; no one has yet discovered for what purpose such a sin- gular conformation has been provided. The ovary contains but one cell; but, as in the Poppies, it has three projecting lines running up its shell at equal distances in the inside, and covered with young seeds (fig: 6.). When the fruit is ripe it is still surrounded by the calyx (fig. 9.), although both petals and stamens have THE VIOLET TRIBE. 67 dropped off; it is an oblong shining case, which splits into three pieces or valves, in the middle of each of which stick the pale chesnut-coloured shining seeds. There is no material difference from this structure in such other plants of the Violet tribe as you are ever likely to meet with; and therefore I shall sup- pose that the whole may be recognized by the cha- racters I have explained. Beautiful as they all are to look at, they would produce anything rather than Heart’s ease if you were to eat them: for their roots have the property of producing sickness in so powerful a manner that they are sometimes used in medicine as emetics. I would therefore advise you to confine your admira- tion to their beauty or their fragrance. The Sweet Violet will have no rival among flowers, if we merely seek for delicate fragrance, but her sister, the Heartsease, who is destitute of all sweet- ness, far surpasses her in rich dresses and gaudy colours. She has become of late a special favourite with florists, who cultivate I know not how many distinct varieties, some of which have flowers of yellow and purple, or all yellow, or all purple, or nearly white, with every. gradation of tint and depth, which one can well imagine. Methinks, I hear my young friends exclaim, are these fine plants, indeed, our humble Pansy, changed by cultivation? is it possible that the little drooping weed, which we have so often gathered among the stubble of corn- fields in the autumn, can ever become the’ gaudy flower of the florist? Even so indeed is it; the FQ 68 LETTER IV. savage woad-stained Britons, were not more different from the well-dressed ladies of the present day, than is the Heartsease from its wild state, since it hasattracted the notice of the gardener. Those children of the wild Pansy, which you see in the borders of the flower- earden, have intermarried with strangers from other climates, and especially with one from the Altaic mountains (Viola altaica), where the race is finer and more vigorous than beneath our northern sky. Before I close this letter let me survey the ground we have passed over. Eight distinct Natural Orders have been examined, all of which are so very easily known from each other, that it is almost superfluous to repeat their characters; yet as there is no more certain method of fixing these matters in the memory than by recapitulation from time to time, I must not only do so, but beg of you to endeavour to get the distinctive characters clearly understood and remem- bered by our little students. Let me now vary the mode of distinguishing them, and put their characters before you in a new form. Of the eight orders, three have an inferior ovary, and five have a superior ovary ; we will take this very conspicuous character, as a preliminary mode of distinction ; for thus we shall simplify the other dif- ferences. Then, of the three which have the inferior ovary, the Evening Primrose tribe has its parts of fructification in fours, the Umbelliferous tribe bears flowers in umbels, and the Myrtle tribe has a great many stamens and aromatic dotted leaves. On the ANALYSIS. 69 other hand, those with superior ovaries may be first separated into such as have a great many stamens, and such as have only a small and certain number. Of the former you have the Crowfoot and the Poppy tribe, the first of which has several distinct carpels, and the last all the carpels grown together into a hollow case ; of the latter the Geranium tribe has the carpels separating from a long hard beak-like centre, the Cruciferous tribe has six stamens of which four are longer than the others, the Violet tribe has anthers with a membranous crest, and a fruit splittmmg into three valves, to the middle of which the seeds are fastened. ‘This will be still clearer to you if put into the shape of a table. Parts in fours—Evening Primroses. Ovary inferior P Flowersinumbels— Umbelliferous Plants. arts not ; = in fours Flowers not in umbels — Myrtles. ( carpels separate—Crowfoots. a great many stamens carpels joined into . a hollow case Poppies. Ovary superior carpels sepa- ' rating from ¢ Geraniums. a long beak few ~stamens ) carpels seta Five Stamens— Violets. Separahing } siz stamens, from a : fens teat of which are short Cruciferous Plants. This table is of no other use than to shew you how to analyse the characters of the subjects you examine ; it does not give you, as you must remark, a correct 70 LETTER IV. notion of the essential characters of any of the tribes, but it states clearly how they differ from each other. They differ from each other in many other respects, but it was not necessary to express any thing further in order to enable you to know them from each other. EXPLANATION OF PLATE IV. I. Tuer Cructrerovus Trise.—A sprig of Shepherd's Purse.— 1. A flower with all its parts in their natural position.—2. The same flower without the calyx and corolla ; it shews the two side stamens, which are the shortest.—3. An ovary cut across, exposing the par- tition, the two cavities and the young seeds, or ovules.—4. An ovule apart, with the end by which it hangs from the side of the partition. 5. The stigma, with the style and a portion of the shoulders of the ovary.—6. A ripe silicle ; a a@ the valves; 6 the point of the par- tition.—7. The partition, from which the valves have been removed, shewing the numerous seeds which hang to it.—8. The partition seen in front, with the marks of the places to which the seeds were attached.—9. A ripe seed, covered with fine hairs.—10. The same cut through perpendicularly, shewing how the embryo is doubled up within it.—11. The same seed, cut through horizontally; a the radicle ; b the two cotyledons.—12. An embryo pulled out of the seed-coat and straightened. II. Tue Viovter Trispe.—A. A piece of Heartsease ; a blade of the leaf ; 6 4 stipules.—1. A view of the stamens and pistil in their natural position, after the petals and sepals are pulled off.—2. One of the horned stamens seen in face; and, 3. the same seen from behind ; in both a represents the membrane, which is characteristic of the natural order.—4. A regular anther, seen in face.—5. A pistil.—6. The ovary cut through to exhibit the three elevated lines on which the seeds are placed.—7. A front view of the hole that leads to the stigma.—8. The head of the stigma split open, with a view of the stigmatic interior.—9. A ripe fruit split into its three valves.—10. A seed.—11. The same cut perpendicularly to shew the embryo lying in the midst of albumen. BeSres es a — gee Neen Z tt dis Vl —", Ka : ite v) aS A UMIOIL: rN \ A \ AN 1 CIFLOP? Ufo J a Yourew, é Viele Z woe. lafseon -/ Atthiwn é¢ Skt). LETTER V. THE PASSION-FLOWER TRIBE—AFFINITY—THE GOURD TRIBE—-THE TUTSAN TRIBE. (Plate V.) POLED ALLL ALLL LOLA LE OLD DD Wuen the Spaniards discovered America they found among other curious things, a flower, which they thought was an allegorical representation of the crucifixion and sufferings of our Saviour. In its anthers they saw his five wounds, in the three styles the nails by which he was fixed to the cross, and in a column which rises from the bottom of the flower the pillar to which he was bound; a number of little fleshy threads which spread from its cup, they com- pared to the crown of thorns. ‘There are cuts, says Sir James Smith, to be found in some old books, apparently drawn from description, like the hog in armour upon our signs to represent the rhinoceros, in which the flower is made up of the very things themselves (ftees’s Cyclopedia). Such travellers’ stories as this, would now find few persons credulous enough to believe them ; the tale is, however, not wholly fabulous. Like many others of the same sort it is composed of truth mingled either with falsehood or excessive exaggeration. There is such a flower, and a highly curious one it is; and so ee LETTER V. far from rare, that you are probably already well acquainted with it, for it is now frequently to be seen trained even to cottage walls. You are surprised at this, and I dare say wonder what this strange flower can be that you have so often seen without discovering in it any of the marvels of the good Spaniards. ‘They called it, in allusion to its mystical attributes, Flos Passionis, a Latm name signifying—Passion-flower, which the moderns have retained. Many species with this remarkable character are known in gardens; they are all Passion-flowers, and are the representatives of the Passion-flower tribe. In other countries, other singular plants are also found, not exactly Passion-flowers, but belonging to the same tribe; as you are never likely to meet with them, I need not trouble you about the manner in which they are distinguished. We will satisfy our- selves with a botanical view of that to which so strange a story is attached. The Passion-flower is a twining plant which helps itself to rise upon others by tendrils like those of the Pea, with which it often scrambles to the tops of high trees, or, if it misses its hold im the ascent, or is by any accident separated from the prop it has selected, hangs down among the branches in elegant festoons. Its leaves are veined in the netted manner ; and are often divided into deep lobes, but not always ; their stalks bear here and there upon their upper edge little hard dark-green shining warts, called glands ; and they have a pair of stipules at their base. THE PASSION-FLOWER TRIBE. 73 The stems when cut through, shew the Exogenous structure ; a circumstance you would have known by aid of the leaves alone, if you had not had the stem to cut. The flowers haye on the outside three large bracts (Plate V. 1. fig. 1. a.), which together form an inyo- lucre. Next these is a calyx, composed of five sepals (fig. 1. 6.) which are generally green on the outside, and differently coloured in the inside; sometimes blue, sometimes purple, now and then yellow or some other colour. Let me particularly call your attention to this, which is a proof that the calyx, in other plants as well as in the Fuchsia, is occasionally co- loured like petals. When you are more of a Botanist you will find that this fact is connected with a curious tale of vegetable transformations, which I may some day relate to you. At the base the sepals are joined together in a shallow cup, from which the petals and other parts arise. The petals (fig. 1. c.) are always of the same colour as the inside of the sepals; but are nearly alike on both sides, are narrower, and are without a singular little horn, which projects from the back of the sepals, just as other horns spring from the corslet of certain beetles. Next the petals come—the stamens, you will say:—not. at all. Next the petals come several rings of beautiful fleshy threads, which spread from the cup like rays, and are splendidly mottled with azure and crimson and white. If there be one part of a plant more beautiful than all others, it is this 74 LETTER V. ray (or crown of thorns, as the Spaniards called it) in the Passion-flower; the crimson blotches upon it really do look like stains of blood. It diminishes gradually in size towards the inside of the flower, till at last it loses itself in some little rings, one of which often surrounds the base of the column we have still to examine in the centre (fig. 2. a.). Bota- nists themselves are hardly agreed upon the real na- ture of these singular rays; while some think them imperfect petals, others think them imperfect sta- mens: a question of very little moment, and which you are, as yet, unprepared to discuss; they are, probably, parts in a state of change from one to the other. In the very centre of the flower, from the bottom of the cup, rises a column (fig. 2.), at the top of which are five stamens, each with a narrow two- lobed anther, swinging from the point of a flat fila- ment ; you will wonder to see that these anthers in- stead of turning their faces to the stigmas, like most other anthers, are so contrived as to turn their backs upon them; so that when they burst the pollen cannot fall upon the stigmas. ‘This, however incomprehen- sible an arrangement it may appear to us, is by no means an event of unfrequent occurrence, as you will hereafter discover; nobody has yet found out the cause of it. What now is the column from which the stamens seem to rise? The base of the filament, you say. To a certain extent, you are right. ‘The outside of the column, which is speckled like the filaments, is con- structed, as you imagine; but if you cut it you will THE PASSION-FLOWER TRIBE. rier find it is only a hollow sheath surrounding a solid slender cylinder, from the top of which grows the ovary. It is an unusual thing to find ovaries that have a stalk in the inside of the flower: but such a structure isnot found in the Passion-flower alone. The ovary is an egg-shaped part, which, when you cut it, is seen to consist of a single cavity, from three elevated lines in which spring the ovules, just as in the Violet. It is surmounted by three styles, which are thicker at top than at bottom, and terminated by thick swoln stigmas. This peculiar form, no doubt, suggested the idea of their representing the three nails of the cross. Thus you see, when this flower is stripped of all that is fabulous, there is still enough left in it to ex- cite our admiration. The fruit is, in all cases, a fleshy egg-shaped body, containing a number of pulpy seeds; but it varies exceedingly in size and colour in different species. In the common blue Passion-flower, it is about as big as a hen’s egg, and orange-yellow; in others, it is smaller, and quite round (fig. 3.); in others, it is as large as a child’s head. Fruit of the latter size are sometimes cultivated for the sake of the sub-acid pulp they contain, and are called Giranadillas ; they are more esteemed in tropical countries, where the eatable fruits are generally bad, than in England, where we have so many really delicious fruits of our own. If you were to look at the seed, you would say it was merely covered by pulp; there is, how- 76 _-*‘ LETTER V. ever, something even here, beyond what you at first perceive. Were you to watch the ovule in its pro- gress to become a seed, you would remark a fleshy sort of jacket, gradually rising from the bottom of the ovule, overspreading its surface day after day, till it had completely enclosed it: and then, on a sudden, becoming soft and pulpy. Such a part as this we Botanists call the ar1LLus ; a part you have often seen in another plant without knowing what it was. The spice called Mace overspreads the Nutmeg, as its jacket does the seed of the Passion-flower, and is the arillus of that aromatic production. The seed may be easily deprived of the pulpy arillus, which will strip back (fig. 6.); and then you will discover that the seed itself is a blackish body, with a brittle sculptured shell (fig. 8.). 1 shall not trouble you about the contents of the seed, further than to say, that they are sweet like a nut, and as good to eat. The only plant belonging to the Passion-flower tribe, which you will find in the gardens, besides Passion-flower herself, is a genus named ZYacsonia (see Botanical Register, tab. 1536.), which is also found in South America, and is so like a Passion- flower, that you will hardly distinguish it, except by the very long tube of its flower. Its rays are short, so that it has, in some respects, less beauty ; but the richness of its colours, and the large size of all its parts, amply compensate for this defect. But, although there is no other genus of the same tribe within your reach, there are several belonging to AFFINITY. en another tribe with which your children must be fami- liar, without calling science to their aid. ‘They cer- tainly have practical Botany enough to know a Melon, and a Cucumber; and, probably, also a Gourd, a Ve- getable Marrow, and a Spirting Cucumber. Those things form part of a small natural order called after one of them, the Gourd Tribe, which is in near affi- nity, as we say, with the Passion-flowers. Now, this word affinity is one of the great practical difficulties in the way of the student of the Natural System of Botany. Not that it need be made so; for I have no doubt I could have taken you to the end of our in- tended journey, without saying a word to you about the matter. But to understand it is essential to those who would form a higher notion of Botany than what can be gathered from the mere power of distinguish- ing one thing from another; and if it could be com- prehended, would form a great aid to you in your future progress. I shall, therefore, take the present opportunity of saying something about the way in which the word is applied, in the hope that I may make it clearer to you than it seems to be to many. Nevertheless, if you do not understand me, you may skip all that follows upon the subject. Arrinity signifies resemblance in most characters of importance. It differs im degree just as resem- blances between animals, which you can see and understand more readily than those between plants. Thus a monkey or baboon are very nearly related to man, although totally distinct ; that is, they resem- ble man in most characters of importance ; and are therefore in affinity with him. Again, a cat and 78 LETTER ‘Vv: a lion agree in a very great number of their principal points of organization ; and are therefore in affinity also. But a cat and a bird, although both of the animal kingdom, disagree in the greater part of their structure ; they therefore are not in affinity with each other. To take an illustration from plants you are now familiar with, compare the Crowfoots with the Myrtles; they both bear flowers composed of calyx, corolla, numerous stamens and pistils, and they both have leaves with netted veins and consequently an exogenous structure; but here their resemblance ceases.—Compared as to other circumstances they are extremely different: as you will see by studying the two following columns :— Crowroors have Lobed /eaves, with an acrid watery juice, and usually with an alter- nate insertion on the stem. Numerous stamens, arising from below the carpels. A superior pisti/, consisting of several carpels, either not at all or but slightly adhering to each other. As many styles as carpels. A very little embryo, which is furnished with a great quantity of albumen for its nourishment when young. They are chiefly herds. Myrrtes have Leaves not at all lobed, usually with an opposite insertion on the stem, and with a volatile oily juice, which is lodged in little transparent spots. Numerous stamens arising from the sides of the calyx. An inferior pisti/, consisting of several carpels, which are all grown into one solid body at the top of the fruit-stalk. Only one style, whatever the num- ber of carpels. An embryo, which is supplied with no albumen for its nou- rishment when young. They are all ¢rees or shrubs. AFFINITY. 79 Thus in all these six important circumstances the Crowfoots and Myrtles are extremely dissimilar ; therefore they are not in affinity with each other. Next let us compare Evening Primroses and Myrtles, which we have seen disagree in the former having the parts of the flower always divided by four, no oil spots in their leaves, and but a small number of stamens. Compared as to other circumstances they are extremely similar, as the followmg columns will shew :— EveninG Primroses have Myrt tes have Leaves sometimes opposite. Leaves usually opposite. Stamens arising from the sides of | Stamens arising from the sides of the calyx. the calyx. An inferior pisti/ with many seeds. | An inferior pzst/ with many seeds. Only one style. Only one style. A fruit which is sometimes pulpy. | A /rwt which is usually pulpy. An embryo with no albuminous | An embryo with no albuminous provision for its infancy. provision for its infancy. Thus in these important circumstances the Evening Primroses and Myrtles essentially agree ; therefore they are in affinity with each other. You will further remark, that the points of difference between them in structure are no greater than what I just now men- tioned; so that the points of resemblance are much more numerous than the points of difference. Having thus given you an idea of the meaning of the word affinity as used in Botany, let me resume my account of the Gourds, which are in near affinity with the Passion-flowers. A Cucumber, which is one of the Gourd tribe, has a twining, scrambling stem, and raises itself by ten- SO LETTER V. drils ; its leaves have a netted arrangement of the veins ; its flowers have a calyx which is like petals in colour ; its stamens grow into a central column; its ovary has only one cavity, with the seeds attached to three lines which pass up its sides; its ripe fruit is succulent in the inside; and its seeds have a sweet nutty taste. Al this reads as if I were really talking of a Passion-flower ; it is these numerous points of resemblance, in important points of structure, which constitute the affinity between the tribes of the Pas- sion-flower and Gourd. In other respects they are materially different. The Cucumber has very rough leaves; it has no petals; its stamens grow in one flower, and its pistil in another; the ovary is inferior; and there is no trace of the beautiful rays of the Passion-flower. All the Gourd tribe participates in these differences, which thus become the essential characters of that natural order. The Passion-flowers are all harmless, and the fruit of many of them is eaten. Here we have another similarity, you will exclaim. Not quite so fast, if you please; I would not advise you to adopt that idea practically, for if you do you may share the fate of the poor sailor, who lately perished, as the newspapers tell us, from drinking out of a gourd- shell. In some countries there are Gourds with a very singular figure ; they resemble a Florence flask, such as oil comes home in, and have a hard rind filled with soft pulp. Very useful bottles are pre- pared from such fruit, by cutting off the end of the THE GOURD TRIBE. SI narrow part which represents the neck of the bottle, and then scooping out all the inside; but it is neces- sary before using them that all the pulp should be removed, and that water should be allowed to stand in them, and be changed several times, till all the bitterness in which the rind abounds be removed ; owing to the purpose to which the fruit is then applied the plant itself is called the Bottle-Gourd. The bitter matter which is thus removed by wash- ing, is not only unpleasant, but actually poisonous, as the unfortunate accident I have alluded to suffi- ciently proved. You will be surprised to hear that it exists universally in the whole of the Gourd tribe, even in the Cucumbers and Melons which you have so often eaten without being poisoned; the truth is, that in these fruits the bitterness is dispersed through so large a quantity of pulp, and there is so little of it, that we are not sensible of its presence; while in the Bottle-Gourd and others, it is so highly concentrated as to become dangerous. ‘That it is found even in the Cucumber you may easily believe, if you call to mind how often that fruit is bitter even when upon the dinner table. You will therefore recollect that the Passion-flower tribe is universally harmless; but that the Gourd tribe is so often unwholesome, that the two or three instances you know of its fruit being eatable are to be considered exceptions to the rule. The length of this letter has already so much ex. ceeded my intention, that I must bring it to a close G 8Y LETTER V. with a brief account of a little natural order of wild flowers, which we may dismiss without giving you much more to learn. The old herbalists had a plant which they called Tutsan( Hypericum); a corruptionof the French Toute- sain, which we might translate ‘“ Allheal”; they also named it Androsemum, which being translated signi- fies “* Mans-blood,” an odd name, which originated in the soft fruit staming the fingers red when bruised, and in a deep red colour being communicated by the leaves to oily or spirituous medicines in which the plant was often employed. This and others of a similar kind are common in meadows, and_ bogs, on heaths, in groves and thickets, and by way-sides, which they adorn with their bright yellow flowers. The species which I have selected for examination is a frequent inhabitant of shrubberies, but not a wild plant; it is called “the tall” (H. elatum); if you have it not at hand any other will do as well. Its leaves have netted veins, are of an oval figure, are placed in opposite pairs round the stem, upon which they are seated without any stalks. If you rub them they emit a strong penetrating disagreeable odour ; the cause of which you may discover by holding them against the ight. They will be seen to be filled with transparent. dots, crowded together and so minute that you perhaps may require a magnifying glass to discover them. It does not always happen that these dots are very small; on the contrary in one of our wild species they are so large that the leaves look as if bored full of holes, on which ac- THE TUTSAN TRIBE. 83 count the species has acquired the name of “the perforated.” The flowers grow in loose clusters at the tops of the shoots; their calyx consists of five sepals which are unequal in size, and which overlap each other curiously at the edges when the flowers are very young. ‘To see this arrangement, cut a young flower- bud across, and you will find that the two largest sepals are on the outside of all (Plate V. 2. fig. 1**); next one of these is a smaller, of which one edge is covered by one of the large sepals, and the other lies upon the edge of a still smaller one within it; the last is matched by a fifth of the same size as itself, standing on the opposite side of the flower. The petals are five, of a bright yellow, and very large for the size of the flower. At the base of the petals, and from below the pistil, arises a great number of stamens of unequal lengths, with very fine yellow filaments, and small roundish anthers; if you take hold of a few of these stamens with your fingers and pull them, a cluster will separate from the rest (fig. 3.); and if you will pull the remainder they also will come away in four other parcels; so that the stamens are really united into five different parcels, although till you began to separate them you did not discover it to be the fact. This is a curious circumstance to which you will find few parallels in other plants. The pistil is an oblong body (fig. 4.) terminated by three styles, each of which is tipped with a little stigma. ‘The inside of the ovary contains three cells, in each of which is a multitude of ovules; to speak G 2 ~ 84. LETTER V, very correctly this pistil is composed of three carpels adhering to each other. The ripe fruit is just hke the pistil, except that it is darker-coloured, larger, and destitute of styles, which drop off shortly after the ovules are fertilized ; it finally ( fig. '7.) divides into three pieces or valves, each of which is one carpel; so that the adhesion between the carpels which took place when the flower was exceedingly young, does not cease till the fruit arrives at a state of dissolution. ‘The seeds are very minute, but worth examining for their exceeding beauty. ‘They are of an oval form, and up one side runs a curious crest (fig. 8.) which gives the seed something the appearance of an ancient helmet. This plant represents the characters of an order called the Zutsan tribe (Hypericacee), into which enter few other genera besides that which compre- hends our wild flowers. Among them, however, are some, found in the tropical parts of America, called Vismias, which yield a resinous substance resembling gamboge. In fact, something of the same kind may be traced in many of the ‘Tutsans themselves. ‘True, gamboge is itself the produce of a tree of the natural order Guttiferee, to which belongs, among others, the Mangosteen tree, which bears the most delicious fruit in the world; that natural order has an exceedingly strong affinity with the ‘Tutsan tribe. I need not recapitulate the characters of the orders explained in this letter, as they are so very distinct that you may safely be left on this occasion to your own ingenuity. In my next letter I shall present you with some very interesting subjects. 85 EXPLANATION OF PLATE V. I. Tur Passton-FLower Trise.—1. A full-blown flower of the Laurel-leaved Passion-flower ; a the involucre, b the sepals, ¢ the petals.—2. A column of stamens; athe last ring of the rays.—3. A ripe fruit of the Red-stemmed Passion-flower.—4. The same cut through, to shew the manner in which the seeds are attached.—5. A seed, natural size, with its arillus on.—6. The same, with the arillus stripped back.—7. A seed magnified, with the arillus on.—8. The samewith the arillus off; shewing the sculptured seed-coat.—9. A seed cut through ; the embryo is seen lying in the midst of albumen in small quantity.—10. An embryo extracted from the seed, with its broad leaf-like cotyledons, and small tapering radicle. (N. B. These are copied from drawings by Mr. Ferdinand Bauer.) Il. Tae Tursan Tripe.—l1*. A flower-bud of Tall Tutsan, shew- ing the calyx.—1**. A view of the manner in which the sepals are respectively arranged when the bud isyoung.—2. A full-blown flower. —3. One of the five parcels of stamens.—4. A pistil.—5. A fruit three- quarters ripe.—6. The same cut through, to shew how the inside is arranged.—7. The ripe fruit separating into its constituent carpels; which leave behind three pieces of their edge, in the shape of three narrow plates, to which the seeds once grew.—8. A seed very highly magnified.—9. A section of the same, shewing the two cotyledons, and a, the thickness of the crest. LETTER VI. THE MALLOW TRIBE—THE ORANGE TRIBE. Ce ean need (Plate VI.) Wet do I remember the pleasure I used to have, when a little fellow just sent to school, in gathering cheeses out of the hedges: it was my first step in Botany ; and it was not without pride that I found myself able to shew my less learned companions how to distinguish the plants that bore those delicacies. Many years after, when the cares and pleasures of life had blotted out all remembrance of the joys of childhood, I was passing a few days in Normandy, with my friend M. de P., when, one day, his little girls came running to me with their hands filled with fine plump fromageons ; 1 know not whether it was the association of ideas that the well-remem- bered word conjured up, or the sweet countenances of those dear children, joy painted in their black and sparkling eyes, and health in their rosy cheeks— but I ate their fromageons with as much delight as ever, and fancied them as superior to all the fruits of the garden in flavour, as they are in perfect symmetry of form. Only compare a vegetable cheese, with all that is exquisite in marking, or beautiful in arrangement in the works of man, and how poor Xv y SS x \ \ iN . ; < Pesstest __ EXBRARY OF THE. WUERoHY Ur ab Pap SAF hee THE MALLOW TRIBE. 87 and contemptible do the latter appear! Not only, when seeing it with the naked eye, are we struck with admiration at the wondrous perfection and skill with which so obscure a point in the creation is constructed; but, using our micrcoscope, sur- prise is converted into amazement, when we behold fresh beauties constantly revealed, as the magni- fying power is increased, till at last, when the latter reaches its limit, we find ourselves still re- garding a lovely prospect, the horizon of which re- cedes as we advance. Nor is it alone externally that this mimitable beauty is to be discovered; cut the cheese across, and every slice brings to view cells and partitions, and seeds, and embryos, ar- ranged with an unvarying regularity, which would be past belief if we did not know, from experience, how far beyond all that the mind can conceive, is the symmetry with which the works of nature are con- structed. Look, then, who list your gazeful eyes to feede With sighte of that is faire, look on the frame Of this wide universe, and therein reade The endless formes of creatures, which by name Thou canst not count; much less their natures aime; All which are made with wondrous wise intent, And all with admirable beauty blent. I perceive, I have been talking of these curious productions, as if you were already acquainted with them ; while it is quite possible that you are not. In that case, step to the road-side, or to the first patch of weeds you can meet with, and there you will be sure 88 LETTER VI. to find what is called a Mallow; we have two very common sorts ; one of which has small pink flowers ; the other, large striped purple ones ; the latter is one of our handsomest wild flowers, and is called * the common,” or, the larger Mallow (Malva sylvestris) ; it is that you are to take as the subject of your study. This plant (Plate VI. 1.) grows two or even three feet high, in places where it is not cropped by cattle. It has an erect branching stem, of a very pale green, covered all over with longish hairs, which fre- quently spring from the surface of the stem in starry (or, as we pedantically say, stellate) clusters. ‘The leaves are roundish, and divided into about five shal- low lobes, the border of which is notched ; their veins are netted. Atthe base of the leaf-stalk grows a pair of small stipules, resembling scales. From the bosom of the leaves spring the flowers singly. Below the calyx are placed three small bracts, forming an involucre (fig. 3. a.). The calyx is composed of five sepals, joined together about half-way; it is quite soft, with long delicate hairs. Five large rosy-purple striped petals, each of which has almost the figure of a wedge, and is notched at the end, constitute the corolla, which spreads wide open, when its proper time for unfolding arrives ; before that time, its petals were curiously twisted together. The stamens are very different from any we have yet examined; they consist of a hollow column, at its upper end, a great number of anthers, bearing, THE MALLOW TRIBE. 89 each of which has a short filament (fig. 1.), and is of a kidney shape, containing only one cell instead of two, as is usual. Formerly Botanists were contented to call this column, a column, and to inquire no fur- ther ; as if they thought it was some new and special organ found only in such plants as the Mallow. At the present day we are too curious to be thus easily contented, and we must have the exact nature of every part explained. This column, then, is caused by the filaments growing fast together, when they are very young, without being able to separate afterwards, except just at the top, where they look like filaments. Suppose the stamens of the Tutsan were joined toge- ther in this way, when young, you would have exactly such a column as is constantly produced in the Mallow. The next object of examination is the pistil (fig. 2.) ; itis formed of several carpels, which grow toge- ther in a circle round a common centre, and so form a sort of flat plate, from the middle of which the styles arise. Like the filaments, the styles also grow together at the bottom into a column, but they soon separate again, and then you may tell, by counting them, that each carpel has its own style, for there is exactly as many styles as carpels. Last comes our acquaintance the cheese, in the shape of the nearly ripe fruit ; we will suppose it to be quite ripe (fig. 4.), for the sake of avoiding repeti- tion. It consists of a number of dry carpels which will separate readily from each other and from the central body to which they were originally joined. gO LETTER VI. Each carpel (fig.5.) contams one seed, with an embryo curiously doubled up and filling the whole of the cavity ; hence as the carpels are all of the same size, and arranged with the most exact regularity on the same level, if a fruit is cut through it will present a singularly beautiful arrangement of the parts, which look like a vegetable star. In the centre, if the fruit is not ripe, is a solid circle from which eleven rays branch off at regular distances, each being sub-divided into two. Between the rays le eleven embryos, the various conyolutions of which, as cut through by the knife, exhibit eleven areas of strange patterns. The kaleidoscope itself can produce nothing prettier than this, except in colour. This account is that of all the Mallow tribe in most respects; and is quite sufficient to enable you to identify it: a power that it is useful to possess because the species are all perfectly innocent. The columnar stamens themselves suffice in a majority of cases. The species yield a large quantity of a ropy transpa- rent almost tasteless fluid, in all the green parts; and it is for this that the cheeses are sought with so much avidity. In India a daily use is made of the cheeses of a Malvaceous plant called Ochro, or in some places Gobbo (Hibiscus esculentus), the mucilage of which is in great request for thickening soups: it is even imported in a dry state into England. Marsh Mallow, which possesses this mucilaginous quality in a high degree, in all its parts, is a favourite material with many physicians, especially the French, for poultices. We are, however, far from exhausting the properties THE MALLOW TRIBE. QI of the Mallow tribe im talking of its mucilage. It has many other and far more important good qualities. In beauty it yields to no part of the vegetable world ; many of the plants called Hibiscus, are trees or shrubs or herbs bearing flowers of the largest size, the most exquisite proportions and the most striking colours ; the common Bladder hetmia for example. One of them, conspicuous for the brilliant crimson of its flowers (Hibiscus Rosa Sinensis), is a vegetable shoe- black ; the petals communicate a black stain to any thing they touch, and the Chinese actually black their shoes with them. Many varieties of it are common in our hot-houses, so that you may try the experiment on your own shoes if you like. Cordage is also produced by several species, from the tough vegetable fibres of their stem. But it is the hairy clothing of the seeds of different plants belonging to a genus that Botanists call Gossypium, which is of such pre-eminent importance as to claim for the Mallow tribe a rank in the vegetable kingdom second only to Corn. ‘That hairy substance is Cotton, which for no conceivable purpose except to yield man the means of clothing himself, is formed in prodi- gious abundance upon the back of the seeds of the Cotton plants, whence it is torn by machinery and afterwards cleaned and spun into thread. Faithless travellers and credulous readers for a long time caused the existence of the Barometz, or Scythian Lamb, to be believed in, a creature said to be half animal half plant; the Cotton plant has far stronger claims to the name of a vegetable sheep. 92 LETTER VI. The simplicity of its characters and the remarkable arrangement of its stamens, render it unnecessary for me to dwell longer upon this natural order. The next to which I shall direct your attention, is that of the Orange, im which I hope to make your little pupils take as much interest botanically, as they already do in a more practical way. Oranges, Shaddocks, Limes, Lemons, Forbidden Fruit, and the like, are all produced by plants which represent a tribe perfectly distinct from the rest of the vegetable kingdom, and which we call the Orange tribe. The are all natives of countries warmer than this, and principally of the temperate parts of India; their fruit is in all cases eatable, although not always worth eating; their leaves and flowers all fragrant, and they are universally evergreens of beautiful ap- pearance. ‘The cells filled with oil, which you find in cutting the rind of an orange, are met with in both leaves and flowers, to which they often give the appearance of being covered with little blisters ; and, as usual, it is in them that the sweet odours are stored up. To understand the structure of this interesting | tribe, let us take the common sweet Orange, a plant or two of which is kept in every green-house, for the sake of the delicious fragrance of the flowers. It has leaves with netted veins, and filled with transparent spots (fig. 6.); they are always jointed just above the footstalk, so that each leaf will readily snap asunder in two pieces. The calyx is a little cup with five shallow teeth: so complete is the combina- THE ORANGE TRIBE. 93 tion between the sepals of which it is composed. Five white fleshy green-dotted petals are placed within the calyx, and within them are ten or twelve stamens that arise from under the pistil; these grow together, in a way that explains well enough the real nature of the column of the Mallow tribe, but that is not characteristic of the Orange tribe itself. The pistil ( fig. 4.) is a round dark-green part, ter- minated by a thick style and stigma: around its base is stretched (fig. 6. a.) a ring, out of the outside of which the stamens originate. If you cut into the ovary, you will find it contains several cells, in each of which is a double row of ovules (figs. 5 and 6.). Thus far there is nothing but a peculiar combina- tion of parts, with all which you are already quite familiar. But as soon as the ovary begins to grow into a fruit, a great change comes over it: numbers of the ovules perish; the thickest part of the rind begins to separate from the lining, and finally be- comes so loose that, as you know, it is easily peeled off; and at the same time a great quantity of little pulpy bags jut forwards into the cavity of each cell, be- coming more and more watery, more and more acid, and then more and more sweet, till at last the whole substance of the fruit is a mass of sweet and delicious pulp. The nature of these bags cannot be readily seen in the Oranges of the shops, but if you examine a bad Orange, such as is usually produced in a green- house, the structure becomes most obvious. Do not, however, suppose that the presence of pulpy bags in the midst of the cells of the fruit is an Q4 LETTER VI. essential character of the Orange tribe; on the con- trary, it is peculiar to the Orange genus (Citrus) only. In all the other genera the fruit is fleshy and fragrant, but not pulpy in the inside. So few plants related to the Orange are ever likely to be met with by you, that I should only fatigue you unprofitably in repeating their names. Let us con- clude, then, for this time with the essential character of the Orange tribe, which, if reduced to its simplest form, may be expressed thus :— Leaves, flowers, and fruit, filled with transparent receptacles of fragrant volatile oil. Leaves jointed, once at least, above the footstalk. Stamens few and hypogynous. Fruit fleshy. To compensate for the length of some of my former letters this is unusually short; for which I suspect you will be inclined to thank rather than to blame me. EXPLANATION OF PLATE VI. 1. Tue Mattow Trise.—A sprig of the larger Mallow (Malva sylvestris).—1. An anther with the upper part of the filament.—2. A pistil, shewing the ovary, column-like base of the styles, and the styles themselves—3. A calyx closed over the growing fruit, with leaves of the involucre at a.—4. A ripe fruit ready to separate into distinct carpels.—5. One of the carpels separated from the rest, and seen from its side.—6. The same, split in halves, to shew the em- bryo; from the position in which the embryo lies, only one of the cotyledons can be seen at a; 6 is the radicle. II. Tue Orance Trise.—A twig of the common sweet Orange. —1. A flower shewing the calyx, the petals spotted with oil, and the 95 tips of the stamens.—2. A stamen, with the anther viewed in front. —3. The same from behind.—4. A pistil, with its disk at @ ; at the lower edge of the ring or disk are seen the scars caused by the sepa- ration of the stamens.—5. A cross section of the ovary, shewing the numerous cells and double lines of oyules.—6. A perpendicular sec- tion of the same ; even at this young period you may see in the rind of the ovary the receptacles in which oil is begmning to secrete; @ the disk.—7. A portion of a leaf magnified so as to shew the oil cells. LETTER VII. THE CHICKWEED TRIBE—METAMORPHOSES OF PLANTS — THE PURSLANE TRIBE— SUCCULENT PLANTS— BREATHING-PORES. wrerrmerrere (Plate VII.) were: From the earliest period of your familiarity with a garden, you must have been acquainted with those sweet aromatic flowers called Pinks, Piccotees, and Carnations, and you must have admired their beau- tiful stripes, and the symmetry with which their petals are arranged. It is also not improbable that you have some knowledge of a mean weed, called Chickweed (Stellaria media), which inhabits every neglected corner of your garden; Corn Cockle (Agrostemma Githago), Bachelors Buttons (Lychnis dioica), tagged Robin, (Lychnis flos Cuculi), and many species of Catchfly (Silene) are also pretty flowers, that you will easily procure either by hunt- ing for them in the fields, or by inquiry after them in gardens. All these agree with each other in a number of cha- racters which are so remarkable as to divide them from all other plants, and to cause them to be esta- blished as a distinct natural order called the Chich- err. Ahe Ohichweedl: LS Ce. | Me Suistane & . DY kn 4 | Y Large flowered Ge GE SOD LIBRARY OF THE _QNIVERSITY OF ILLINOIS vis THE CHICKWEED TRIBE. Q7 weed tribe ; which is composed for the chief part of plants of little interest or beauty, among which there is not a single species with unwholesome properties. Uninteresting as many of them are, they are so com- mon that every one who pretends to botanical know- ledge must learn how to recognize them, even if it were not for the sake of the few kinds, which, like the Pink, are our familiar acquaintances. To understand the structure of the Chickweed tribe, I shall not ask you to take the Chickweed itself, because it is a plant with very small flowers ; let us rather seek some species in which all the parts can be easily seen ; as a Pink for instance. Here isa pretty species, the glaucous Pink (Dianthus glaucus) of Scotland; if you have it not in your garden, any other will do as well, provided it is not double. This little herb is called glaucous, from a Latin word signifying blueish-grey, because its leaves, like those of many other pinks, have such a colour in a remarkable degree. Its stems are very much swoln at the joints, where the leaves are set on. ‘The leaves are exceedingly narrow, undivided, and rather rough at their edge; they have only one single vein which runs through them from one end to the other. How then are we to ascertain whether this plant is Exo- genous or not? for there is nothing here to shew whether the veins have a netted structure; there is apparently only one vein to examine. I must con- fess this looks very like a difficulty; and I dare say you will now suppose that the time has come when you must have recourse to patience and a microscope, H ‘OS LETTER VII. to learn whether there are two cotyledons in the embryo or only one (see page 13); believe me, how- ever, we have not yet arrived at so disheartening a point. ‘There are in fact many ways of shewing you how to determine whether this is an Exogenous plant or not, without counting the seed-leaves. ‘That which I select is one of the easiest to understand; but I must first mention a few matters that I have not hitherto touched upon. You are no doubt acquainted with some of the idle tales that are told by the ancient poets, of people being changed into trees, or animals, or rocks; one young lady for example, not only cried her eyes out, but was altogether changed into a running stream, and another was transformed into a spider, be- cause she dared to emulate the goddess of wisdom in tent-stitch ; these occurrences they called Metamor- phoses, a name which Botanists have borrowed for something of a similar nature which really does hap- pen in plants. Hitherto ‘I have always spoken of the different parts of the flower as so many totally distinct organs, and it is undoubtedly true that the petals, stamens, and pistil have very different offices to per- form. But, at the same time, it seems equally certain that all those, and several other parts, are in a very great degree constructed like leaves; that at a very early period, when they were first formed, they were absolutely the same as leaves of the same age; that it is only after they have been growing for some time that they begin to assume the characters under which they finally appear; and that consequently they are METAMORPHOSES OF PLANTS. Q9 very often found resuming the appearance of common leaves if any thing occurs to interfere with their in- tended structure before it is entirely fixed. “Thus we find leaves in the place of petals, or as they say petals metamorphosed into leaves, in some kinds of double Tulips; sepals and pistils often changed to leaves in double Roses ; all the parts of the flower turned into leaves in other plants; and a multitude of similar cases with which the Botanist is acquamted. You will find all this so fully demonstrated in my Intro- duction to Botany, Book vi., or in other works of a like nature, that there is no doubt of the fact; and the doctrine is now the foundation of modern views of the real structure of flowers and fruit. It is not my plan to enter into such questions in these letters, but I could not avoid calling your attention to the cir- cumstance. Now mark the practical application of this know- ledge. If the parts of the flower are only leaves in a particular state, any of those parts in which veins can be discovered will serve to shew the ar- rangement of the veins as well as the true leaves themselves. In the Pink the petals are fully ex- panded, and full of veins; they are therefore fitting objects to examine; and their structure will tell us whether the Pink is Exogenous or not. You will find them distinctly netted, and thus that question is set at rest. This then, which is an Exogenous plant, has oppo- site undivided leaves seated on the swoln joints of the stem. The calyx consists of a tube composed of five 100 LETTER VII. sepals jomed together and separated only near the points. Five petals arise from within them, each of which has a stalk and a blade; the stalks, or claws as they are called (ungues), are very narrow, and stand side by side within the calyx; the blades are much expanded, and irregularly lacerated at the end. Stamens there are ten, rising from beneath the ovary, out of a short stalk (Plate VII. 1. fig. 2. a.). The ovary is superior, and contains but one cell, in the centre of which is a slender receptacle (fig. 3. a.), covered with a great many ovules. The styles are two, each terminating insensibly in very narrow fringed stigmas. The fruit becomes a dry case or capsule, opening at the point with four teeth or valves (fig. 4.). The structure of the seed is variable, and not important for our present purpose. Such is the character of the Pink, and such to a great extent is that of the tribe it represents. It may be said to consist in these marks. Stems swoln at the joints ; leaves opposite and undivided ; stamens few and hypogynous ; ovary with many styles, one cell, and a central receptacle covered with ovules. Nothing like this has been previously shewn to you. The genera are very uniform in their structure, and are distinguished by marks that every one may ob- serve. Two divisions are formed, one of which has the sepals united into a tube, the other has them all distinct. In the first division is found the Pik, which is THE PURSLANE TRIBE. 101 known by the bracts at the base of its calyx (fig. 4. a.); and some others, of which the following are the most remarkable ; Silene or Catchfly which has three styles and a crest at the top of the stalk of each petal ; it derives its English name from its often secreting a viscid matter in which flies are caught; the Cockle (Agrostemma) which has five styles and undivided petals; Lychnis, to which the Ragged Robin (L. flos Cuculi), and Batchelors Buttons (LL. dioica) belong ; to say nothing of the splendid Chalcedonian Lychnis of the gardens, which has five styles and divided petals. To the second division we refer Chichweed (Stellaria), which has three styles and two-lobed petals, Sandwort (Arenaria), which has three styles and undivided petals, and Mouse-ear Chickweed (Cerastium), which has five styles and a curiously shaped taper seed- case with ten teeth. So little interest attaches to these plants that I leave them here, and proceed to notice another order which resembles them in many respects ; and which is upon the whole more beautiful. Imagine you have a Chickweed with two sepals and one style, all the other points of structure in the flower remaining the same; and you will have an order that, while it seems to resemble the Chickweed tribe so much as to be almost identical with it, neverthe- less differs in several important particulars in the manner of growth. Not only are the leaves alter- nate instead of opposite, and the stem destitute of swellings at the joints, but there is a constant dis- position on the part of the stems and leaves to become , £F £ 102 LETTER VII. fleshy, or as it is usually called succulent. Plants thus constructed belong to the Purslane tribe, so called because the now-forgotten Purslane, which was once in much esteem as a salad, belong to it. They are often remarkably beautiful on account of their bright red or yellow flowers; are always harmless and wholesome in their properties; but are sometimes, when the petals are small, mean-looking herbs. You cannot take a better specimen of the Purslane tribe than the large-flowered Calandrima (Plate VII. 2.), a Chilian plant that is now a good deal culti- vated. Its soft and succulent stems and leaves are exceedingly dissimilar to those parts in the Chick- weed tribe. The calyx is formed of two leaves (figs. 1. and 4..); there are five petals which pay their homage to the sun by unfolding their crimson drapery beneath his earliest beams, and rolling up again as soon as the light of his countenance is withdrawn. A considerable number of stamens succeed the petals ; and in the centre is an ovary with one cell and a central receptacle covered with ovules; it is surmounted with a style which ends in a broad hairy lobed stigma. The fruit when ripe splits into four valves (fig. 4.) ; which allow the escape of a number of black seeds (figs. 5. and 6.), altogether resem- bling in their internal structure the seeds of most of the Chickweed tribe. The obscure little Water Chickweed (Montia fon- tana); aneat looking American genus of hardy plants called Claytonia; the Purslanes themselves (Portulaca), many of which are very handsome ; and the Chilian > BREATHING-PORES. 105 Calandrinia are the most common representatives of the order. While the principal part of the plants belonging to the Chickweed tribe is found in meadows, or shady spots, or in situations and climates where they are abundantly supplied with moisture, the Purslane tribe, on the contrary, chiefly rejoices in hot dry exposed places, where they will flourish at a time when every thing else has fallen a victim to drought and heat. They owe this power to the peculiar nature of their stems and leaves; which, as I have already men- tioned, are succulent. They require, in consequence, a peculiar mode of cultivation, which I will now ex- plain to you. When I gave you in my first letter a brief account of the minute and beautiful arrangements by which leaves are able to perform their vital actions, I omit- ted to say anything about their breathing-pores or stoMATA. ‘The time has now come when I must tell you what they are. All leaves are covered by an exceedingly thin and delicate skin, which you may often peel off. If you put a small piece of this in water, and look at it with a microscope against the light, you will remark a number of very small roundish or oval spaces, through the middle of which a line passes. Andif you have patience enough to look at a great many of them, you will in time perceive some of them opening a sort of mouth at the place where the line is. ‘These are what are called breathing-pores; they are organs by which the leaves inhale and exhale air, or vapour 104 LETTER VII. suspended in air. In some leaves they are extremely large and numerous, and such leaves perspire through the breathing-pores in very great quantity, as the Vine ; in others they are so small or so few, as to ad- mit of scarcely any perspiration, as in the Purslane, and in succulent plants in general. It is thought, indeed, that the character of succulence is owing to leaves being unable to get rid of the water ab- sorbed by the roots, and so becoming, as it were, dropsical. Attention to this difference in the power of per- spiring in different plants is one of the keys to a knowledge of the right method of cultivating them and it has been applied for years to succulent plants, by keeping them in what is called a dry stove ; that is to say in a hot-house, the air of which is kept dry by refraining from watering the floors or earthen pots in winter. Succulent plants are, when in a state of rapid growth, so imperfectly supplied with the means of perspiring, that they require all the assistance which can be obtained from a dry atmosphere, to be able to part, by the leaves, with the water that is im- pelled into them through their roots; and conse- quently, if ever, in a rapidly growing state, they are kept in a damp atmosphere, they become dropsical and unhealthy, or soon decay. But in the winter, 7 the little power of perspiration which they possessed in the full vigour of their summer growth is very much diminished, and is in fact reduced to almost nothing. Their roots will nevertheless go on absorb- ing moisture from the soil as long as the soil contains SUCCULENT PLANTS. 105 any, and this, if the moisture is in much quantity, is certain to produce decay and death, because the excess of water, which cannot be afterwards parted with by the leaves, becomes putrid. Such being the case, it is found necessary to deprive succulent plants of all water at their roots in winter, and to leave them for support to the vapour which always will exist in the air at that season in a climate like that of England. It is for these reasons that succulent plants succeed so much better than others in sitting-rooms. In such situations, plants are killed by want of light, and want of moisture in the air; for the air of all sitting- rooms is necessarily very dry. But succulent plants apparently require less light than most other plants, and are certainly benefited rather than injured by a dry atmosphere. I should therefore advise you, if you are anxious to have a garden in your sitting apartment, to fill it with succulent plants, to the ex- clusion of all others. The Purslane tribe is far from being the only one in which succulent species are found; they might exist In any, and in fact do ina great many natural orders, the majority of whose species are not succu- lent ; some orders, however, abound in them more than others, as for example, the Houseleeks (Crassula- cee), the Torch-thistles (Cactacee), the Asclepiadacee, the Huphorbias (Euphorbiacee), and the Asphodels ( Asphodelee). But it is time that an end were put to this letter, especially as the next must, I fear, be a very long one. 106 EXPLANATION OF PLATE VII. I. Toe Cuickweep TriBe.—A piece of the Glaucous Pink.—1. A petal apart; on its stalk is a curious double raised plate.—2. The stamens and two stigmas, as seen when the calyx and corolla are cut off; a is the stalk of the ovary.—3. A perpendicular section of an ovary, shewing the central receptacle, a, on which the ovules grow. —4, The ripe fruit invested with its calyx, and having the bracts @ at the base.—5. A seed.—6. The same divided perpendicularly, so as to shew the embryo.—7. An embryo taken out of the seed.—A. a seed of another plant, Batchelors Buttons (Lychnis dioica), cut through perpendicularly, and shewing the curved embryo; a albumen. Il. Toe Purstane Trise.—A leaf and a portion of a flower- branch of Large-flowered Calandrinia.—1. A flower-bud, with the sepals, and the corolla peeping through it.—2. The stamens and pistil—3. A perpendicular section of the ovary, shewing the central receptacle on which the ovules grow.—4. A fruit beginning to open, with the two sepals by which it is protected.—5. A seed, with a portion of its stalk.—6. The same cut through, to shew the embryo and the albumen, a. rsNicost oo LANG aes Pe {S) | ; Be OS pared OS % i Ss ae rede: her. Seu ey tlhe A D> y) VAIO. pee 740 ae Lh Mhwreott's LETTER VIII. THE ROSE TRIBE—BUDDING AND GRAFTING—— THE PEA TRIBE. POLL L ID LL LIL LL LDL POLL DA (Plate VIII.) POP RAL LEAL LOLOL O LOE re You, perhaps, remember, when you were begin- ning to study Botany, how you fell into the error of supposing that the Strawberry belongs to the Crow- foot tribe, and that I then explained to you the cause of your mistake. In this letter I propose to take the Strawberry, for the purpose of illustrating the natu- ral order to which it belongs, which we call the Lose tribe, because the Rose is one of the genera com- prehended in it. I am sure, that the mere mention of this favourite plant, will ensure your attention to the history of its relations. The Strawberry (Fragaria) is a herb with three- parted leaves, and a pair of large membranous sti- pules at their base (Plate VIII. I. 1. a.). The veins of the leaves are netted. When the Straw- berry plant is about to multiply itself, it puts forth naked shoots of two sorts: one of them is prostrate on the ground, and ends in a tuft of leaves, which root into the soil, thus forming a new plant; or, as it. 108 LETTER VIII. is technically called, a runner; the other kind of shoot grows nearly erect, and bears, at its end, a tuft of flowers, which afterwards become fruit ; or at least what is commonly called so. The calyx of the Strawberry is a flat green hairy part, having ten divisions ; it is, therefore, caused by the union of ten sepals, five of which are on the out- side of the others, and smaller. As you become more and more acquainted with Botany, you will find that it is an extremely common thing for the parts of the flower to consist each of several rows. ‘This is the first time I have mentioned it, and it is the first time it has occurred in the calyx; but you have already seen it in the rays of the Passion-flower, in both the stamens and carpels of Crowfoots, and in the stamens of many of the other orders we have passed by. The corolla consists of five petals. The stamens are very numerous, and are placed in a crowded ring round the pistil, as in the Crowfoot ; but, you will observe, that they grow out of the side of the calyx (fig. 2.), and not from beneath the carpels. The pistil of a Strawberry is very much lke that of a Crowfoot: it consists of a number of carpels, arranged in many rows, and with great order, upon a central receptacle ; each carpel has a style, which arises from below its point (fig. 5.), and terminates in a slightly-lobed stigma. In the inside of the ovary . is one single ovule. With the flower, the resem- blance between the Crowfoot and the Strawberry ceases. THE ROSE TRIBE. 109 You will almost wonder, now that you know how the young flower of a Strawberry is constructed, how so singular a fruit is to be formed out of such mate- rials; especially if you should have chanced to meet with the ingenious explanation given of it by some Bo- tanist, whose name I forget, that it is a berry with its seeds on its outside. Many and strange are often the changes that take place in the organization of a pistil in the course of its transformation into a fruit: and they are highly curious in this case. If you would really understand them, you should watch the Straw- berry in the progress of its growth. You would then see that the first occurrence after the petals have fal- len off, and the calyx closed on the tender fruit, con- sists in the receptacle of the carpels beginning to swell; and, shortly after, in the carpels themselves gaining a greater size and a more shining appear- ance; while, at the same time, their styles begin to shrivel up. At a more advanced stage, the carpels are found but little augmented in size, while the re- ceptacle has increased so very much in dimensions, that the carpels are beginning to be separated by it, and the surface of the receptacle can be distinctly seen between them. A little older, and the carpels seem scattered, in an irregular manner, over the sur- face of the receptacle, which has become soft and juicy, while they have remained almost stationary in size. All along, the swelling receptacle has been pushing the calyx aside, as being no longer of use to it; and, at last, you scarcely remark the calyx, in consequence of the much greater size of the re- 110 LETTER VIII. ceptacle. This part finally gains a crimson colour, swells more and more rapidly, acquires sweetness and softness, and at last is the delicious fruit you are so well acquainted with:—in that, its final state, the carpels are scattered over its surface in the form of minute grains, looking like seeds, for which they are usually mistaken. You, however, know better than to fall into this common error; for you have seen, that, at first, they had each a style and stigma, which seeds never have ; and you can now, by cutting them open (fig. 8.) detect the seed (fig. 9.) lying in the inside of the shell of the carpel. The Strawberry is, therefore, not exactly a fruit; but is merely a fleshy receptacle bearing fruit; the true fruit being the ripe carpels. Cinquefoils (Potentilla), are little herbs, usually with pretty yellow flowers, found growing on banks and on commons, among the short grass; one of them is called Silver-weed (P. anscrina), on account of the white, and almost metallic, appearance of the under- side of its leaves. They are so like the Strawberry in flower, that there is no Botanist who could tell you how to distinguish them in that state. But they do not bear Strawberries ; that is to say, after their fower is withered, the receptacle does not become soft and pulpy; but it always remains hard and dry, and is completely hidden by the carpels. ‘This plant, then, must be very nearly related to the Strawberry. The Raspberry and Bramble (Rubus), also claim kindred with the Strawberry, because of their like- ness to it. They are shrubby plants, having their THE ROSE TRIBE. is stems covered with hard hooked prickles ; in this re- spect they differ from the Strawberry. Their leaves are divided, in various ways, according to their kinds, and have large stipules at the bottom of their stalks; here they agree with it. Their calyx has only five divisions instead of ten; which is a diffe- rence; but their petals are five; the stamens nume- rous, and arising out of the side of the calyx; and their pistil composed of a number of carpels arising out of a central receptacle ; these, again, are resem- blances with the Strawberry in important points. Let us examine the fruit. The Raspberry has a dry core, off which you may pull the little thimble-like fruit, and you will not find any of the dry grains which stick upon the outside of the Strawberry. But, look again; what are the little dry threads that you see rising from the centre of a multitude of little projec- tions with which the whole surface of the Raspberry is covered? Surely they are styles; and, if so, the projections out of which they grow, must be carpels in aripe state. ‘This is really the case; the carpels of the Raspberry, instead of remaining dry as they become ripe, swell and acquire a soft pulpy coat, which, in time, becomes red: they are crowded so closely, that, by degrees, they press upon each other, and, at last, all grow together into the thimble-shaped part which you eat; in order to gain this succulent state, they are forced to rob the receptacle of all its juice, and, in the end, separate from it, so that when you gather the Raspberry, you throw away the re- ceptacle under the name of core, never suspecting 112 LETTER VIII. that it is the very part you had just before been feast- ing upon in the Strawberry. In the one case, the receptacle robs the carpels of all their juice, in order to become gorged and bloated at their expense ; in the other case, the carpels act in the same selfish manner upon the receptacle. Another plant very like Cinquefoil is Avens (Geum), one species of which, called the Herb Bennet (G. urbanum), is common enough in hedge-rows. It grows a foot or two high, and has the leaves upon the stem in three lobes, while those at the bottom of it are in many divisions. ‘The flower of this plant is so extremely like that of Cinquefoil, that you could not distinguish the two. But its fruit is a sort of bur, composed of innumerable stiff bristles, which all spring from one common centre, and are terminated by hooks at the point. The bristles are the styles which, like those of the Geranium, have grown stiff and long; and the hooks are the hardened points of them where they have curved back, and separated from an upper portion which drops off. The central part is a mass of carpels, the receptacle of which is hard and dry. A beautiful mountain plant, frequently met with in the Alps of Europe, called Mountain Avens (Sieversia montana), and often seen in gardens, where it is cul- tivated for its large yellow flowers, and its diminu- tive stems covered with large deeply-lobed leaves, offers a further imstance of the changes which the fruit of the Rose tribe undergoes between youth and old age. When the fruit of Mountain Avens is ripe, THE ROSE TRIBE. 13 it looks like a silken plume springing out of the cup of the calyx, and as it waves about in the wind one may almost fancy it a tuft of feathers accidentally fastened to the flower-stalk. A botanical examina- tion dispels the illusion, and shews that the appear- ance is caused by the carpels having preserved their styles, which become very long and are covered all over with loose silky hair, which has grown since they were young. A similar phenomenon occurs in the Virgin’s bower (Clematis), and in the Pasque flower (Anemone); but the most remarkable instance of the production of hairs so as to change the whole ap- pearance of a part, is met with in the Venetian Sumach (Rhus Cotinus), which the French call Arbre a per- ruque or the Wig Tree. You have perhaps seen this plant, which is by no means uncommon in shrubbe- ries, ‘shaking its hoary locks” at you as the breeze waved the branches, and set the wigs in motion, in the midst of a crowd of blood-stained leaves; if you have not, I would advise you to seek for it in the autumn, at which season only it wears its wig ; in the spring and summer it does not want it and will not put iton. The explanation of its strange appearance I cannot give better than in the words of Professor De Candolle. ‘The panicle (that is the cluster of flowers) of Rhus Cotinus is almost entirely smooth at the flowering season ; after that period all the flower- stalks which bear fruit, continue to remain smooth or scarcely downy; but, on the contrary, on those whose fruit is not formed, and they constitute the greatest number, there appears a great quantity of i 114 LETTER VIII. scattered hairs, which give them a shaggy aspect, on which account gardeners have named the plant the Wig Tree ; it is probable that this excessive production of hairs is caused by the sap, which was destined to nourish the fruit, not having any employment in those stalks the fruit of which is not formed, and expending itself in the production of this extraordinary quantity of hair.” The genera hitherto mentioned are upon the whole better adapted to give a student a correct notion of the character of the Rose tribe, than the Rose itself. It is now necessary that we should examine this charming flower, in the construction of which you will find as much to admire as in its external attractions. ‘The leaves and stems of Roses are sufficiently like those of the Bramble, to render it unnecessary for me to insist upon any peculiarities in those parts. In the flower much seems to differ, although in reality but little essential difference exists between Roses and other Rosaceous plants. It has a calyx of five divisions, some of which are very like small leaves. ‘To these succeed five petals; and within the latter is a great number of stamens, which grow from the side of the calyx. You will not at first sight perceive any pistils: in the centre, indeed, is a tuft of stigmas, but no ovaries are visible; upon further search, however, you may discover, espe- cially if you press the flower forcibly between the finger and thumb, that the styles project through the neck of an oblong green body, which being below and on the outside of the calyx, looks like an inferior THE ROSE TRIBE. LS ovary. If you split the flower perpendicularly, you will then perceive that this body, that looks like an inferior ovary, is in reality the tube of the calyx, which is contracted at the place where the stamens originate, into a narrow orifice, through which the tops of the styles protrude; and that the ovaries are included within that tube, forming as usual the bot- tom of the styles. Perhaps you will gain a clearer notion of this if you suppose that part of the tube of the calyx of the Strawberry, which is included between the letters 6 and ¢ in the accompanying figure (fig. 2.) to be lengthened very much, while all the other parts retain their size and position; in that case the carpels, with their receptacle, might become much shorter than the tube of the calyx, instead of being longer, and if the latter were con- tracted at its mouth, no part of the carpels would be visible except the tops of the styles and the stigmas. The ripe fruit, or hep of the Rose, is nothing more than the same tube of the calyx turned red and fleshy, the sepals, and petals, and stamens having dropped off; in its inside will be found the carpels changed to bony grains, covered with coarse stiff hairs. : Thus are constructed those plants which most exactly belong to the Rose tribe. ‘They are all harmless, and when they are sufficiently agreeable to the palate, eatable ; very often, however, their juice is so very austere and astringent that no use can be made of them except in medicine. ‘They have some- times been employed in domestic medicine, especially 12 116 LETTER VIII: Herb Bennet, the roots of which have been found by: some physicians as valuable in the cure of fevers as the Jesuit’s bark itself. Very nearly allied to the Rose tribe are two other sets of plants, which by some are reckoned mere subdivisions of it, though by others they have been considered distinct natural orders. We need not trouble ourselves with that imquiry; I dare say you will prefer to know what they are, and how they are characterized. The first of these is the Apple tribe, to which belong all those plants which agree with the Rose tribe m every thing but the carpels being distinct and supe- rior ; in lieu of which they have the carpels united and adhering to the tube of the calyx. Take an Apple tree in flower, as an example of this. It is a plant with leaves having netted veins, and stipules at their base. ‘The calyx has five divisions, the petals are five, and there is a great many stamens growing out of the sides of the calyx. In the centre you will find five styles; but their ovaries, instead of being merely enclosed within the tube of the calyx, adhere and form one body with it. It is this cireum- stance that gives rise to all the difference that you find in the fruit itself. An apple is a large fleshy body having at one end what is called an eye ; which is in reality the remains of the calyx surrounding the withered stamens. ‘The principal part of the flesh is the tube of the calyx, but the central part is the carpels, also grown fleshy, and at this period undis- tinguishable from the calyx itself; that their number THE ALMOND TRIBE. was five is shewn by the five cavities in the centre of the fruit, each of which contains one or two seeds. Now it is obvious, if this description be carefully con- sidered, that the fruit is the only thing by which the Apple is known from a Rosaceous plant. ‘The same kind of structure is found in the Pear, and the Quince, and the Mountain Ash. In the Medlar and the Hawthorn it seems as if the fruit contained two or three stones instead of the open cavities of the Apple; but in reality the only peculiarity in those fruits consists in the lining of their cavities being bony instead of thin and papery, as you may easily satisfy yourself by looking at their flowers. All the plants of this tribe are as harmless as the genuine species of the Rose tribe itself. The other group to which I have referred is the Almond tribe. ‘This is less different in structure than the Apple tribe, but more dissimilar in sensible properties. It consists of species which have all the essential parts of structure of a common Rosaceous plant, but which bear fruit like that of a Plum. The Plum-tree itself, for example, has leaves with netted veins and stipules at their base; a calyx of five parts; five petals; and a great number of stamens arising out of the sides of the calyx. But in room of many carpels, there is only one, and that one changes to a fleshy body, containing one single seed, enclosed ina hard stone. The hard stone is the lining of the cell of the carpel, separated from the fleshy rind that is on the outside. This kind of fruit is called a Drupre. What is found in the Plum exists 118 LETTER VIII. equally, and but little modified, in the Apricot, Peach, Nectarine, Almond, and Cherry, all which are species of the Almond tribe. They would not perhaps be separated by Botanists into a distinct natural order, upon so slight a character, as the fruit being a Drupe, if that circumstance were not accompanied by a differ- ence in the qualities of such plants. Instead of being perfectly wholesome, they are in many cases highly poisonous, as the Common Laurel (Prunus Laurocera- sus), the leaves of which yield the dangerous infusion called laurel-water. This is owing to their yielding a volatile principle called Prussic acid, which in its concentrated state is one of the most dangerous of poisons. It is it which gives the well known flavour to Almonds, Ratafia, and the liqueurs called Ma- raschino, Kirschenwasser, and Mandel amara, and which is so often employed to mix with creams. Do not however suppose, that on this account there is any real danger in eating the fruit of Cherries, Plums, Peaches, and the like; in those fruits the prussic acid exists in such very minute quantity, as to be in- capable of producing any deleterious effects. Nature has provided amply against the ill effects of such an insidious enemy, by rendering its presence instantly perceptible by an intensity of flavourthat cannot be mis- taken. Thereare those, indeed, who have condemned the whole tribe for the qualities of a few, and who have gone so far as to assert, that the dried leaves of the common Sloe were poisonous. It is not probable that the green leaves of that plant would produce any seriously bad effect ; and it is certain that when dried BUDDING AND GRAFTING. 119 they would lose what little poison they may have pos- sessed when green, because the prussic acid principle is so volatile as to be immediately dispersed by the mere exposure of the leaves to heat. Plants of the Almond tribe have also this peculiarity in which they differ from the Roses; their bark yields gum; as you may see by the cracked branches of dis- eased Cherry and Peach trees. Like the Roses them- selves, they have also a great deal of astringency ; and their bark has been used in the cure of agues and fevers with considerable success. If you analyze the characters of these three orders, you will find that their differences may be expressed thus :— many Carpels.—The Rose Tribe. one Carpel.—The Almond Tribe. Ovary inferior - : : The Apple Tribe. The woody species of these three natural orders are Ovary superior . ; objects of such universal cultivation, Roses for their odour and beauty, Peaches, Apples, &c. for their utility as fruit-trees, that I cannot do better than explain to you the principles upon which the opera- tions of budding and grafting, by which they are propagated, are conducted. If you do not care for multiplying Apples and Pears, I dare say you would at least be amused in making one kind of Rose grow upon another, and in converting the wild Briars of the neighbouring hedges into objects of greater beauty. The gardener’s operations of budding and grafting, depend for success upon the fact, that a portion of 120 LETTER VIII. one tree will grow upon another if skilfully applied to it. There are those who have believed that a piece of one plant would grow upon any other; and that Roses might be budded upon Black Currant bushes or Pomegranates; this, however, is untrue. It is a certain fact, that one tree will grow upon another only when the two are very closely allied in structure. Thus a Pear will grow upon a Medlar or a Mountain Ash, but not so well as on some other Pear; a Rose will grow upon any other Rose, but not upon an Apple. This is a fundamental rule. In the next place, the stems of all plants consist of buds, and of the part that bears them; the latter has no power of growing without the former, but the for- mer can grow without the latter. or example, if I plant a portion of a stem deprived of its buds, it will die, notwithstanding all the care I can take to pre- serve it; but if I take the bud of a plant without any stem, and place it in earth, it will grow, if due precautions are employed; this shews, that the pro- perty of increasing a plant resides in the buds ex- clusively. It is not, however, necessary to separate the bud from the stem; on the contrary, the two taken together are frequently employed, when they are called cuttings; if the bud alone is employed, it retains its own name. ‘These are the next points to attend to. Thirdly, both cuttings and buds will grow in other media than earth, as for instance, in water, or damp moss, or in any material which is capable of furnish- ing them with a constant supply of moisture and BUDDING AND GRAFTING. 121 food. Nothing is more proper to furnish this than the stem of a tree in which the sap is in motion ;_ be- cause sap is moist, and at the same time, is the food of plants ready prepared for them to consume it. Hence, if a cutting, or a bud be carefully planted in the stem of a tree, they will grow; their roots will be insinuated beneath the bark, and form new wood, and so strong an adhesion will take place between them, that no force can afterwards separate them. Thus, if you would bud one plant upon another, the plan is this; it must be done when the sap is most in motion, and when the bark can be easily divided from the wood; you then cut a narrow slice off the branch which you wish to increase, taking care that it has a well-formed bud upon it; with a smart jerk, the small quantity of wood that adheres to the slice may be taken off, leaving nothing but the bud attached to the bark. Then, with a sharp knife, an incision must be made lengthwise through the bark of the plant in which your bud is to grow, and at the upper end of that incision, a transverse cut, so that the two will together form the letter T. The bark is next to be lifted up on each side of the longitudinal incision, and the bud, with its adhering bark, is to be slipped in. If the whole is then bound up with worsted or matting, a union will take place between the bud and the branch into which it is inserted, and a new plant will be created. If you would graft one plant on another, you must follow a different plan ; for grafting is effected with cuttings, and cuttings cannot be so conveniently slipped 122 LETTER VIII. beneath bark, except at one end. ‘There are many ways of performing the operation of grafiing, one of which is the following :—You cut off the upper end of the branch on which you wish to insert a cutting; and you then pare the end of the branch flat, equally on both sides, till it resembles a long wedge. ‘This done, you slit the lower end of the cutting, and pare away its wood to two flat faces, which correspond with the faces of the branch on which it is to be made to grow, You are then to fit the cutting accurately to the branch, taking care that the bark of both touches exactly, and if they are bound together with worsted or matting, as before, the operation is completed. As however by this method the cutting is less readily supplied with sap than in the case of buds inserted beneath the bark, it might perish before any union between itself and the branch could take place; to prevent this, it is usual to surround it with a thick coating of clay, which adheres to the surface of both ‘branch and cutting, prevents evaporation, and also keeps the two more firmly applied to each other. These are the simple means by which such impor- tant operations as the multiplication of rare and valu- able plants, by making pieces of them grow upon those which are worthless, are performed. If we possessed no such power, it would be almost useless to occupy ourselves with improving the quality of fruit trees, for we should be unable to perpetuate them. Here I would recommend you to pause for the pre- sent ; and when what relates to the Rose ‘Tribe is fully THE PEA TRIBE. 123 mastered, to proceed to the second half of this long letter. There is, perhaps, no natural order which is more easily recognized than the Pea tribe, nor one in which greater interest is usually taken; it is so rich in plants useful for food, as the Pea, Bean, &c. or for forage, as Clover and Lucerne ; or dyes, as Indigo and Logwood ; or timber, as Brazilwood, Rosewood, and the American Locust Trees ; or medicine, as the Senna plant; or gums, as the Arabian Acacia; and attrac- tive for their beauty, as Lobinias, Laburnums, Bladder Sennas,and the noble tropical species of Butea, Jonesia, and Bauhinia, that it would be difficult to point out any group of plants in which there is more to instruct and delight the student. The Pea tribe is so vast that the last enumeration of the species by Professor De Candolle, occupies between four and five hundred closely printed octavo pages. It will, therefore, be impossible for me to do more than give you asketch of the general character by which this extensive assemblage is held together. It consists of plants bearing pods, formed upon the same plan as that of the Pea, and called Lecumess ; this is the great essential character, and the only one which is universal. It is, therefore, necessary to teach you, in the first instance, how you are to know a Legume with certainty. Imagine to yourself a carpel which grows long and flat, and usually contains seve- ral seeds, and which, when ripe, separates into two valves or halves; recollect, also, that the seeds all grow to one angle only of the inside of the carpel ; 124 LETTER VIII. in a word, study a Pea-pod, and you will know what a legume is. You must not expect, however, that it will always be exactly like a Pea-pod; on the con- trary, it is longer or shorter, larger or smaller, harder, thinner, or differently coloured, contains more or fewer seeds; or, in short, may vary in many ways: but it will always be formed upon the same plan. This is what you are to take as the character which holds together all the subdivisions of the Pea tribe. The most striking feature in these plants, next to the legume, is the singular arrangement of the petals, which gives to a very large proportion of the whole natural order the name of Papilionaceous, or Butterfly- flowered. By this title, we distinguish the first divi- sion of the Pea tribe; as an example of which a common Pea flower would answer the purpose. I however, send you a sprig of the narrow-leaved Restharrow (Ononis angustifolia, Plate VIII. 2.). It has leaves the veins of which are at first sight ribbed rather than netted; you will, however, find, that the netted structure is what they really possess ; at their base is a pair of stipules as in the Roses and their allies. The calyx is formed of five sepals, that unite in a short tube (figs. 2. & 3. a.). The corolla consists of five petals, one of which is larger, and stands at the back of all the others, wrapping them up before the flower expands (figs. 2. & 3. b.); this is the standard, or vexillum. In front of the standard are two smaller petals (figs. 2. & 3. ¢.), which are placed nearly parallel with each other, converging a little at the point; they are the wings, or ale, and THE PEA TRIBE. 125 are carefully folded over a boat-shaped curved part of the corolla, which is placed in front of all the rest ; this part, called the eel, or carina (figs. 2. & 3. d.), is formed of two petals, which are slightly united at their lower edge, as you may discern by pulling the keel away from the calyx, when you will see their two stalks ( fig. 4.); the corolla is, therefore, formed of the same number of parts as the calyx, but so masqued that you would not have at first suspected such a thing. This is what is called a butterfly- shaped flower; some poetical Botanists having fan- cied a resemblance between the expanded flower and a butterfly at rest. Let us miss the stamens for the present, and pass on to the ovary (fig. 6.), which is a tapering green hairy part, gradually narrowing into a style which ends ina minute stigma. Its legume is a short flat body (fig. 7.), to which the withered style sticks. When ripe it splits into two halves, to each of which a seed or two (fig. 8.) 1s attached. Papilionaceous flowers may be themselves separated into those which have their stamens united, and those which have their stamens separate. To the first belongs the Restharrow ; which has nine of the stamens joined together about half-way (fig. 5.), and a tenth a little separated from the others. It is here, also, that are found nearly all those species of the Pea tribe with which you are likely to be acquainted. Peas, Beans, Vetches, Clover, Trefoil, and Lucerne, are known to every body; all these you can easily procure for examination. Laburnum, too, with its branches of 126 LETTER VIII. golden flowers, Furze (Ulex europeus), and Broom (Spartium scoparium), which are almost too beautiful to be inhabitants of northern countries, French Ho- neysuckles (Hedysarum coronarium), with their crim- son clusters; and the singular Bladder Senna (Colutea arborescens), the pods of which explode with a loud report when smartly pressed between the fingers, are species of Papilionaceous plants of frequent occur- rence: all which it would be well for you to study, and compare with the characters you will find im systematic works. Indigo (Indigofera tinctoria), which has proved so valuable as a dye, you will not meet with easily in this country ; but you may procure the Laquorice plant (Glycyrrhiza glabra), the roots of which are so exceedingly sweet. Ths second group of Papilionaceous flowers, with the stamens separate, comprehends the chief part of the showy New Holland shrubs, called Pultenea, Gompholobium, Daviesia, &c., but not a single Eu- ropean species, nor any thing worth pointing out for its utility. The next division of the Pea tribe consists of the Cassias and their allies, which are remarkable for not having Papilionaceous flowers ;—in place of which they have their petals spreading equally round the pistil, as in other plants; their stamens are also usually spreading and separate. The irregularity of growth which causes the Papilionaceous appearance in the last division, also exists among these plants, so that you will generally find them with some of the petals or the stamens larger than the remainder. THE PEA TRIBE. £37 Few of them are ever seen in this country, but in foreign climes they are exceedingly abundant. Cassias themselves, some of which yield the well-known medi- cine called Senna, are common in all parts of the tropics; the Logwood, the Tamarind, the Barbadoes flower-fence (Poinciana), the brilliancy of whose orange-coloured flowers is too intense to be steadily looked upon, the fragrant Asoca Tree of India (Jonesia), which Botanists have consecrated as a floral monument to one of the most learned of Oriental scholars, and the Judas Tree (Cercis siliquastrum), which makes all Turkey put on a violet robe, in its flowering season, belong to genera of the Cassia division. ‘To these may be added, as other remark- able plants, the horrid Acacias (Gleditschias), whose trunks are covered with stiff branching spies, and which are so very remarkable in cold countries for the airy Mimosa-like appearance of their foliage ; the Carob Tree, or Algaroba (Ceratonia Siliqua), the sweet pods of which are used for food in Spain, and whose seeds are supposed to have been the ori- ginal carat weight of the goldsmiths, the Tonga-bean plant (Dipterix odorata), with the perfume of whose seeds you are doubtless acquainted; and, finally, Bauhinias, those large climbers which hang among the trees of tropical forests, like enormous cables, twisting round trunks and branches till they utterly destroy them. The third division of the Pea tribe is that of Mi- mosas. Figure to yourself a plant with the sepals and petals of the Cassia group, only so small as 128 LETTER VIII. scarcely to be visible; the flowers growmg in com- pact clusters; and the stamens not only very nu- merous, but so long and slender and delicate as to resemble silken threads tipped with very little an- thers. If you can imagine such a structure you will have a sufficiently correct idea of the Mimosa divi- sion, the beauty of which, on account of the multitude of flowers they bear, and the gay colours in which they are invested, is of so peculiar an appearance, that one of them, a nearly hardy tree (Acacia Juli- brissin), is actually called by the Persians, in whose country it grows, the Gul ebruschim, or Rose of Silk. Here belong the curious Sensitive plants (Mimosa), whose many parted leaves shrink from the touch of the very wind that blows upon them, which close up and appear to go to sleep at night, and which seem as if struck with sudden death if they receive any rude shock; of these plants the balls of flowers are peach-coloured. ‘To the genus Acacia, of which great numbers are found in New Holland, where: they are called Wattle Trees, also belong the spiny gum trees of Arabia and Senegal; the greater part of the species have yellow flowers, and many of them broad dilated leaf-stalks, in room of the many-parted leaves which they bear when young. The differences of these three divisions of the Pea tribe may be expressed thus :— Flowers papilionaceous . . Papilionaceous Plants. § Stamens few—Cassias. Flowers not papilionaceous * Stamens numerous—Mimosas. 129 With this I take my leave of you for the present, promising that my next letter shall be shorter, if it is not more interesting. EXPLANATION OF PLATE VIII. 1. Tue Rose Trise.—!l. A leaf, a few flowers, and fruit of a Strawberry Plant ; « stipules.—2. The calyx and pistil cut through to shew the origin of the stamens; @ sepals, /—e tube of the calyx.—3. A stamen seen in front.—4. The same seen from the back.—5. A carpel; a the ovary, J the style, ¢ the stigma.—6. A fruit cut through perpendicularly to shew the fleshy receptacle, and the grains, a, sticking to it. Compare this with fig. 2.—7. A ripe grain.—8. The same cut through to shew the seed.—9. A seed extracted from the grain.—10. An embryo, with the radicle at the upper end. Il. Toe Pea Trise.—l. A piece of the Narrow-leaved Rest- harrow (Ononis angustifolia).—2. A flower seen from the side ; a sepals, 5 standard, c wings, d keel.—3. The same flower seen in front ; the letters refer to the same parts.—4. A keel apart, shew- ing the two stalks of the petals which form it.—5. Stamens.—6.. A pistil—7. A ripe legume, with the calyx adhering to it.—8. A seed; a the cord by which it was attached to the receptacle.—9. The same cut open, shewing the position of the embryo, of which one cotyle- don only is visible. LETTER IX. THE PROTEA TRIBE—THE AMARANTH TRIBE. weer (Plate IX.) Ir you cast your eye back over the various tribes we have passed in review, you will remark that they all agree in one circumstance, however diffe- rent they may be otherwise. They all have both calyx and corolla: that is, two distinct rows of parts on the outside of the stamens; and the petals are never joined together: on this account they are called Polypetalous, a name which is made by many Botanists to designate the large portion of the vege- table kingdom to which they belong. By and bye you will learn that another portion of considerable extent is called Monopetalous, because the petals are united by their edges into one tube or body; and I have now to explain that a good many natural orders, which have either a calyx without any petals, or no calyx at all, receive the name of Apetalous. ‘They are often also called imperfect or incomplete, with reference to their want of petals; it is to some of these that I wish next to direct your study. The first with which we shall begin, is what is called the Protea tribe, a group of exotic plants very much cultivated in green-houses for the sake of their beautiful or singular foliage, and the great masses of t ee ota ‘ Fiabe Lowe oon Checileng. LIBRARY ee a en JUNIVERSITY OF 1ULINOIS THE PROTEA TRIBE. 131 minute flowers which are borne by some of them; but totally unknown in a wild state in Europe. It would be easy to name some kind with which you might make a personal acquaintance, by inquiring of your gardener after Hakeas, or Persoonias, or G'revilleas ; but you will probably prefer that I should in this instance send you a copy of a drawing by Mr. Ferdi- nand Bauer of one of the handsomest of the kind found by him in New Holland, and named Si Joseph Banks's G'revillea (Grevillea Banksii). The leaves of this plant, like those of the whole tribe, are exceedingly dry and hard; they are divided into many narrow lobes, but this is not by any means universally the case; on the contrary, they are fre- quently perfectly simple and undivided. The calyx (Plate IX. 1.) is a long narrow tube, slit on one side ( fig. 1*.), and turned down at the point so as to give the border a very oblique and bagged appearance ; by disturbing the bag with the point of a pin it will divide into four concave lobes, each of which (fig. 2.) allows an anther to nestle within its cavity. ‘The pistil consists of a long hard style, rather abruptly bent above the middle, terminated by a thickened one-sided stigma (fig. 1**. & 1* b.), and arising from a hairy one-celled ovary having a jagged scale at its base (fig. 4. a.). This scale is one of the things which used to be called nectary, under the idea that it was formed for the purpose of secreting honey or nectar ; but that term is now abandoned. ‘The style is so long that you would wonder how it could ever have been confined within the calyx ; and the stigma K 2 132 LETTER IX. is so far off the anthers that you will find it yet more difficult to imagine how the pollen is to touch it; both these are arranged ina very simple way. Before the flower opens, the stigma, as the style lengthens, is pressed against the point of the calyx; but here the sepals adhere so firmly that they will not open; the consequence of which is that as the style goes on lengthening it gradually takes a bend up- wards, and pressing forcibly against the upper side of the calyx, splits it open, by separating the two sepals upon whose line of union it is forced. The pressure of the stigma upon the point of the calyx causes the latter to be moulded into a sort of socket, in which the anthers actually lie; so that as soon as the stigma begins to be loosened, by the growth of the style after the latter has slit the calyx, the pollen is gently taken out of the anthers by the cup of the stigma; which, when it finally separates altogether and rises up, carries the pollen away along with it. In time the calyx falls off, and the ovary grows into a hard dry fruit (figs. 5. & 6.), which opens like a legume, and exposes to view a couple of seeds. Other Proteaceous plants are formed upon a similar plan: their calyx is often separated into four distinct sepals, and then no socket is formed to hold back the stigma; or there are other variations of minor impor- tance, but in the absence of petals, in the origin of stamens from the face of the sepals, and in the peculiar fruit, they all agree. What causes the most striking difference in their appearance, is the flowers of some growing singly THE AMARANTH TRIBE. Soa among the leaves, and of others being collected into compact heads. ‘Those genera which have the latter structure, are the handsomest and most usually cul- tivated; the Proteas which are found at the Cape of Good Hope, in dry, barren, stony, exposed situations, are most noble looking objects, in consequence of their beautiful feathery flowers being half hidden by large red, or white, or black-edged bracts of the purest colours. Banksias and Dryandras are chiefly valued for their handsome leaves ; some of the latter are so fringed with long hairs as to resemble the plumes of birds. They are applied to scarcely any useful pur- pose; but appear to be perfectly harmless: their seeds are sweet, and are eaten sometimes as nuts, both in Africa and South America; one of them, called Witteboom (Protea argentea), is the common fire-wood at the Cape of Good Hope. But let us leave these showy and useless strangers for a tribe that is known to every one who has a garden. Love-lies-bleeding (Amaranthus caudatus), Prince’s Feathers (Amaranthus), G'lobe Amaranths (Gomphrena globosa), 7’ricolors (Amaranthus tricolor), and Cockscombs (Celosia coccinea), have been culti- vated as long as gardens have been prized ; they form, along with some others of a similar structure, what is called the Amaranth tribe. This natural order, like the last, has: no corolla. Its calyx consists of five crimson sepals (figs. 2. & 3.), of so dry a texture, that you would say they were really dead; these are sur- rounded by a number of bracts, of the same colour and texture as themselves. It is owing to the dry- 134. LETTER IX: ness and thinness, and usually gay colours of these parts, that Cockscombs and the like owe their glossi- ness and beauty, and also the property they possess of remaining for months without fading. ‘The remain- der of their organs are constructed upon the simplest plan. A few anthers, usually five (fig. 2.), and an ovary with two or three styles (fig. 4.), having but one cell and one ovule, complete the apparatus by which such a plant is increased. When the fruit is ripe, the shell of the ovary becomes very thin, and bursts in the middle by a horizontal opening (fig. 4. a.); the seed (fig. 5.) is a little flat body, with a slender embryo (fig. 6.), coiled round some mealy albumen. It is difficult to mention an order much more simply constructed than this, and yet how perfectly are all the parts adapted to the end for which they are created. Even a provision for a beautiful appearance is not neglected, for in order to compensate for their smallness, we find the flowers developed in large masses, and aided by multitudes of shining bracts which contribute very essentially to their fine appear- ance. With an assurance that these plants are all as harmless as they are beautiful, I take my leave of you till another day. 135 EXPLANATION OF PLATE IX. I. Tur Protea Trise.—l. A flower of Sir Joseph Banks's Gre- villea, seen in front, of the natural size.—1*. The same magnified and viewed from the side ; a the socket of the calyx, 6 the stigma.— 1**, The upper end of the style and the stigma viewed in half profile. 2. The upper end of a sepal, with the anther a nestling in it.— 3. An anther.—4. An ovary, with the scale, a, its base.—5. A ripe fruit, natural size.—6. The same burst open.—7. The seeds taken out, with a moveable partition that separates them just brought into view.—7*. The same magnified.—8. An embryo.—9. The same with the cotyledons divided a little. (All these are after a figure by Mr. Ferdinand Bauer.) II. Toe AMARANTH TrisE.—l. A bit of the inflorescence of Love-lies-bleeding, of the natural size.—2. A calyx containing stamens; a bracts.—3. A calyx containing a pistil; @ bracts.—4. ripe fruit; a the horizontal line where it opens.—5. A seed.—6. The same cut perpendicularly ; a the radicle, and 4 the cotyledons of the embryo. LETTER X. THE MARVEL OF PERU TRIBE—THE OAK TRIBE— STRUCTURE OF DICOTYLEDONOUS WOOD. nnn nennnnrere (Plate X.) wn So accustomed are people to identify gay colours with the corolla of a flower, that it is always difficult to make them believe the ovary and red striped part of the Marvel of Peru, to be really a calyx. Such, however, is undoubtedly the fact. The Marvel of Peru (Mirabilis Jalapa) is the re- presentative of a tribe named after it, belonging, like the subjects of my last letter, to the Apetalous division of Dicotyledonous plants. It has fleshy pe- rennial roots ; jointed stems, which perish at the first attack of frost; and broad opposite leaves, with netted veins. Its flowers appear in compact clusters ; and are each surrounded at the base by a green invo- lucre, divided into five segments, so as to resemble a calyx, for which it would be certainly mistaken, if it did not sometimes bear two flowers within the same involucre ; a kind of structure that never is found in a true calyx. Each flower consists, firstly, of a funnel-shaped calyx (Plate X. 1. fig. 1.), divided at the end into five orange and red plaited lobes, and contracted at | he Ma reel pe Leri , So THE MARVEL OF PERU TRIBE. 137 the base (fig. 1. a.) into a roundish fleshy ball ; secondly, of five stamens of unequal lengths, arising from below the ovary (fig. 3. a.), round which they form a fleshy cup, and then adhering to the sides of the calyx ; so that they are actually perigynous and hypogynous at the same time. The ovary ( fig. 4. c.) isa superior body, containing a single ovule, which grows from the bottom of the cavity; it is terminated by a long thread-shaped style, which ends in a cluster of little round warts ( fig. 3. b.), forming astigma. ‘Thus far the structure is as simple as that of the Amaranth and Protea tribes; nor will it be found more complex in the fruit. As soon as the flower begins to fade, the roundish fleshy ball at the bottom of the calyx, swells and grows harder, contracting at the top, and in time throwing off the thin and coloured part. At last it acquires a woody texture, shrivels round the veins, and becomes an oblong brown nut (fig. 6.), with a little hole at its poimt (a.), where the upper coloured part of the calyx fell off. Upon opening it, you will find the fruit, with a very thin shell, and the remains of the style at the top (fig. 7. ¢.). Within it lies a single seed having an embryo (fig. 7. a. 6.), rolled round a quantity of mealy substance, which is the albumen (d.). Such is the character of the natural order that contains the Marvel of Peru, which is by far the most handsome genus it comprehends. Generally, the order consists of obscure weeds, which are rarely 138 LETTER X. seen in gardens, although they are common enough in tropical countries. It differs obviously from the Protea tribe in the stamens being hypogynous ; from the Amaranth tribe in the calyx being all in one piece ; and from both in the singular circumstance of the lower part of the calyx becoming hardened and forming a sort of spurious shell to the fruit. ‘This last is the essential character of the Marvel of Peru tribe, or Nyctaginee; which I only introduce to you as a striking instance, firstly, of the highly coloured condition often assumed by the calyx, and secondly, of the singular manner in which one part is occasionally employed by nature to perform the part of another. Very different from these, although also belonging to the Apetalous division of Dicotyledonous plants, is that most interesting natural order, which includes the Oak, and the Sweet Chesnut, the Beech, the Hlornbeam, and the Hazel; in short, the larger part of our common European trees. In consequence of its containing the Oak it bears the name of the Oak tribe. Until I shall have explained to you the real origin of all the parts you find in these plants, and the singular manner in which they change between the infancy of their flowers, and their old age, you will have had but a feeble idea of the wonderful power the parts of plants possess of assuming un- usual forms after they have been once developed. If it be true that flowers are generally seen in a mas- querade dress, as some Botanists poetically assert, it certainly is here that their disguise is the most im- penetrable. THE OAK TRIBE. 139 The Hazel is one of the most accessible to you when it is young, and a good illustration of the struc- ture of the others. At the earliest period of the spring you must have remarked the branches of the Hazel loaded with little yellow tails, which swing about as the wind disturbs them, and fill the air with a fine and buoyant powder, the particles of which may be seen glittering in the sunbeams like motes of gold. ‘These tails are called carxins (Plate X. 2. jig. 1. a.), and are composed of a great number of little scales, which are arranged one behind the other with the utmost regularity, as you may easily discover by inspecting them, before they separate. Each scale has on its inner face about eight anthers, that seem to arise out of a two-lobed flat body, which ad- heres to the scale (fig. 2.); no other structure is to be found ; apparently neither calyx, nor corolla, nor pistil; nothing but the two-lobed body sticking to the scale and bearing the stamens. Botanists con- sider the scales bracts, and the two-lobed body a calyx in an imperfect state. This then is an instance of a simpler kind of orga- nization, than any you have before met with in a flower. It is, however, not quite characteristic of the Oak tribe, for the Hornbeam has no calyx what- ever, while the Oak, and the Beech, and the Sweet Chesnut have a much more perfect one than the Hazel. If the Hazel had none but stamen-bearing flowers, you would never have any nuts in the autumn; for there is nothing in those flowers which could by any 140 EETTER(“X: possibility change into a nut. In this plant not only are the stamens and pistils in different flowers, but in different parts of the plant, and organized upon quite a different plan. If you observe attentively those buds of the hazel which grow near the catkins (fig. 1. b. b.), about the time when the stamens are shedding their pollen, you will perceive some little red threads protruding beyond the points of the buds, and spreading away from the centre; those are the stigmas, and the pistils are enclosed within their scales, where they are safely protected from accident and cold. At the earliest moment when the stigmas can be discovered, let the scales be removed (fig. 3.), and you will find the flowers clustered together among a quantity of soft hair, which seems provided as an additional means of shielding them from the weather, and to serve the same purpose as the warm lining of down, which the birds provide for their young when they first break the shell and before they are fledged. Kach of these flowers is surrounded by a jagged sort of cup (fig. 4. & 5.), which is originally much shorter than they are, but which in time grows considerably longer ; that cup is the involucre. The flower itself consists of a jagged superior calyx (fig. 5. a.); an ovary with two cells and two seeds (fig. 6.), and two long thread-shaped crimson stigmas. ‘Thus you see the calyx of the pistil-bearmg flower is much more perfect than that of the other kind of flower ; but it is still very imperfect. The pistils and the stamens being thus separated, there would be no chance of the pollen of the one THE OAK TRIBE. 141 falling on the stigma of the other, and fertilizing it, unless an unusual quantity of stamens was provided ; hence it is that in a fine day in spring the whole air is, as I have just said, so impregnated with particles of pollen, that they cover every thing as with a fine dust. By degrees, as warm weather advances, the pro- tection of the scales of the bud ceases to be necessary to the young flowers, which swell and burst through them; the involucre daily grows larger; the stigmas having fulfilled their destiny, shrivel up; the ovary enlarges; one of its ovules grows much faster than the other, and gradually presses upon it till it smo- thers it; the shell hardens, an embryo makes its appearance, and by degrees fills up the cavity; and at last you have a perfect nut, with its husk (fig. 8.), or involucre. At the point of the nut is to be seen the remains of the calyx (fig. 9. b.); but no trace can be found of the cell and ovule which were smo- thered; so that a one-celled fruit is produced by a two-celled ovary. You will now know why nuts sometimes grow in clusters, and sometimes singly ; if cold or accident should destroy any part of the cluster of pistils in the bud, but a very few nuts, per- haps only one, will grow and ripen; but if they are mostly saved, you will then have the large clusters which are so common in seasons which haye been preceded by mild springs. The nut itself affords an excellent illustration of the structure of a dicotyle- donous embryo; the two great fleshy lobes into which the nut separates when freed from its skin (fig. 9. ¢.), 142 LETTER X. are the cotyledons; the little conical part at one end (e.) is the radicle, and the small scale-like body which lies between them in the inside (d.) is the plumule, or young stem. Still more curious than those of the Hazel are the changes that occur during the growth of the fruit of other genera of the Oak tribe. In the Oas itself the involucre is formed of a great many rows of scales, which gradually grow larger and harder, and more numerous, and at last become what you call the cup of the acorn; a part you would never have guessed could have been made out of a number of little leaves, if you had not watched their successive changes. The ovary at first contains three cells, and each cell two young seeds; but in obedience to the constant command of nature, one of the seeds grows faster than the rest, presses upon the other cells and seeds, gradually crushes them, till at last, when the acorn is ripe, all trace of them has disappeared. In the Beech, the involucre originally consists of a vast quantity of little thread-like leaves, which en- close a couple of pistils. These leaves gradually grow together, and over the pistils, so as to form a prickly hollow case, which completely encloses the nuts ; at last, the case rends open spontaneously into three or four woody pieces, and makes room for the nuts, or mast, to fall out. As in the Oak, one of the ovules destroys all the others, so that out of six young seeds, but one is found in the ripe nut; here, how- ever, you may generally find the five that have THE OAK TRIBE. 143 perished remaining like little brown specks, sticking to the top of the cell of the nut. In the Sweet Chesnut, alterations in character, and the destruction of one thing by another are carried still further. In that plant, the imvolucre, which, when full-grown, is a hollow case, covered over with rigid spines, was in the beginning a number of little leaves which gradually grew together as in the Beech ; they kept acquiring with their age a greater degree of rigidity ; their veins separated, and formed clusters of spines, till at last the whole surface of the husk was covered with little spiny stars; each star was in the beginning a leaf, and its rays the veins of the leaf. ‘The pistils each contained six or seven cells, with a couple of ovules in each; yet the ripe nut has only one seed: so that in the course of the growth of a chesnut no fewer than six cells, and thirteen ovules are destroyed by the seed which actually grows. I feel sure you will now agree with me, that if any plants can be said to exhibit themselves in a masque- rade dress, these are they; for without this expla- nation, who could have supposed that the husk of the filbert, of the beech, and of the chesnut, were all of the same nature, and constructed upon the same plan as the cup of the acorn; and especially, who could have supposed that the chesnut, with its single seed, could ever have originated from an ovary of seven cells and fourteen ovules. It is among these trees that you will find the best specimens of the Exogenous structure of the wood of 144 LEDTER: xX. Dicotyledonous plants, a subject upon which I as yet have said almost nothing. Get a branch of Hazel, Beech or Oak, and divide it horizontally, so as to have a view of the whole of the inside from one side to the other, the section forming a circle which is bounded by the bark. Let the section be rendered smooth bya sharp knife or a plane, so that all the parts may be distinctly seen; you will then remark in the centre a pale roundish spot, which a glass will shew to be formed of a soft spongy substance: it is the piru, a cellular provision of nature for the support of the young buds when they are too weak to obtain food from more distant sources. Next the pith follow several rings of woop, each of which is composed of an infinite number of tubes, and was the produce of one year’s growth, so that the number of the rings tells you the number of years the branch has been in acquiring its present size; the most external of the rings is the youngest, and also the palest, while the most internal or the oldest is of a deep brown colour ; the pale is called the sarwoop, the brown the HEARt- woop ; the latter, which is much more durable than the former, is filled with a substance of a hardening nature, which was originally formed in the leaves, and which is stored up by Providence in the centre of the stem, where it lies beyond the reach of accident or injury, until old age comes and produces decay ; originally the heartwood was sapwood, and that which is sapwood now, would have become _heart- wood in a few years, if you had not cut off the branch. It is in the sapwood chiefly that the vital STRUCTURE OF DICOTYLEDONOUS WOOD. 145 energy of the stem resides, and it is through it that the sap rises in the spring for the supply of the buds and leaves ; an Exogenous tree can therefore lose the whole of its inside without suffering much diminution of growth, so long as the sapwood remains uninjured, and this is the reason why trees that are hollow go on growing century after century, just as if their inside were still sound. On the outside of the wood is the bark, which binds up and protects all the other parts, and down which the returning current of sap descends towards the roots. Next carry your eye attentively over the section, from the bark to the pith, and you will remark that a number of fine pale lines are drawn as it were from one to the other, forming delicate but broken rays ; these lines, which are composed of flattened cells, and named MEDULLARY RAYS, are in reality the ends of extremely thin plates connecting the pith and the bark together; they perform an important part in the system of vegetation, for it is they which con- vey the descending sap from the bark to the centre of the stem ; it therefore is they which are the cause of the production of heartwood, and all trees without them must be destitute of it; as is the case with monocotyledonous plants, which are always softest in the centre. Thus you see the sap, which rises from the roots is carried upwards in the sapwood, down again in the bark, and latterly into the hidden recesses of the trunk, by the medullary rays, all three currents L 146 LETTER X. moving at the same instant, but without the slightest interference with each other. Can any thing be more admirably adjusted than all this? By means of a system of tubes and cells va- riously arranged, the whole of the important business of the conveyance of food to the leaves, and of the peculiar properties formed there from the leaves to the centre of the stem, and down to the extremest roots, is carried on in the most certain and effectual manner, even in the loftiest and most gigantic forest trees. Only conceive what a wonderful combination of powers must be provided to enable a tiny leaf, not perhaps half an inch long, on the highest branch of a tree, to procure its food from roots sometimes 250 feet off, or at a distance equal to six thousand times its own length. But I must not dwell further upon this subject, in- teresting as it is; to works on Vegetable Physiology you must refer for a full elucidation of all such matters. Bearing in mind, that the Oak tribe is constantly known by its imperfect apetalous flowers, and its singular involucre, you are in no danger of forgetting it. Formerly, the Birch and Alder, the Poplar and Willow, and the Plane, were considered as also be- longing to it; and the whole were called Amentaceous, because of their stamen-bearing flowers being con- stantly arranged in catkins, or amenta, as they are technically designated. But these trees are so ex- tremely dissimilar in other respects, that they now form several independent tribes. 147 Of the distinctions of these I shall by and bye give you some account ; for the present, I must leave you till you have examined for yourself, as you easily may, the highly singular phenomena I have explained to you. EXPLANATION OF PLATE X. I. Tae Marve or Peru Trise.—l. A flower of the Common Marvel of Peru (Mirabilis Jalapa); a the thickened base of the calyx. —2. The same part magnified, with the upper part of the calyx cut away.—3. The fleshy base of the stamens a, from within which rises ~ the thread-shaped style, terminated by the stigma 6.—4. A perpen- dicular section of the fleshy base of the stamens and pistil; @ the base of the separate parts of the filaments; 6 the base of the style; ¢ the ovule seen in consequence of a part of the shell of the ovary being cut away.—5. Anthers.—6. A ripe nut; @ the closed up orifice of the calyx.—7. A perpendicular section of the nut, shewing the fruit standing erect in the inside of the hardened base of the calyx; ¢ the base of the style; « the radicle, and 4 the cotyledons of the embryo rolled round the mealy albumen d. I]. Tue Oak Trise.—l. A twig of Hazel (Corylus Avellana); @ the stamen-bearing catkins; } the buds containing the pistils.—2. A scale of the catkin, shewing the two-lobed body, and the stamens.— 3. A cluster of pistils bearing flowers, in a very young state, with only one of the scales by which they are protected remaining.—4. A pistil- bearing flower, inclosed in its involucre.—5. The same cut open; @ the calyx.—6. An ovary divided perpendicularly; @ the calyx.—7. The same divided horizontally.—8. A ripe nut in its husk, or in- volucre.—9. A nut cut through perpendicularly; @ the remains of style; 5 remains of calyx; ¢ cotyledons; @ plumula; e radicle. LETTER XI. THE NETTLE TRIBE—WOODY FIBRE—THE BREADFRUIT TRIBE—THE WILLOW TRIBE. we (Plate XI.) rere terre ererercerecrereccrcerrere Tue tribes of Dicotyledonous Plants, with only a calyx to their flower, are far from being exhausted with those we have already seen. On the contrary, there is a great many races, the structure of which is extremely curious. I must, however, be content with selecting three of the commonest for further illustration, and with referring you for a knowledge of the remainder to the systematic works of Bota- nists. Let one of these be the Nettle Tribe ; we will not, however, select the Nettie itself, because of its stings, but begin with a harmless plant called Common Pel- litory (Parietaria officinalis), which you may find every where on old walls, or in dry waste places. This species grows either prostrate, or erect, 1s very much branched, has reddish stems and leaves, and clusters of minute reddish-green flowers in the bosom of the leaves (Plate XI. fig. 1.). Over all its surface are scattered stiffish hairs, which do not sting, but Te Mellow abe LIBRARY © PUR te UNIVERSIDY OF iLLNVUIS . ¢ THE ‘NETTLE TRIBE. 149 which would if they were stiff enough. At the base of each leaf is a pair of shrivelled brownish sti- pules. The flowers of this plant are of three sorts, those which have stamens only, those which have stamens and a pistil, and those which have a pistil only. As the first and second are constructed alike, let us consider them as essentially the same; especially as their pistil is seldom perfect. To each of these flowers there is a calyx with four hairy divisions (fig. 2 & 3.) ; opposite to each division is a stamen ; and in the centre is a pistil more or less imperfect. The filaments are worthy of examination; their lower end is firm, smooth and fleshy; but it abruptly alters to a withered shrivelled part, so dissimilar in aspect that you would think it must be a distinct organ. Before the flower opens the shrivelled part is pressed down by the segments of the calyx, which are finally forced asunder by the filaments with force, so that the flower opens with some degree of elasticity; a pro- vision, in all probability, to secure the scattering of the pollen, by which the distant pistils may be reached. The flowers that contain the pistils are mixed among the others, and like them consist of a calyx with four divisions ; but as this contains no stamens, its figure is not roundish, but sharp-pointed, like that of the ovary, to the surface of which it is closely applied. The pistil consists of one ovary containing a single seed (fig. 7.), of a thread-like style, and of a pin-headed stigma, the little fringes of which 150 LETTER Xi spread in all directions, and are admirably contrived to catch the grains of pollen floating in the air. The fruit is an oval shining blackish lenticular grain (fig. 8.), which contains a single seed, with an in” verted embryo lying in the midst of fleshy albumen (fig. 9.)- Such is essentially the manner in which all the remainder of the Nettle tribe is organized. Pistils and stamens in different flowers, leaves covered with rough or stinging hairs, elastic stamens, and lenticular grains, are common to them all. Nettles, which are so remarkable for the intolerable pain, and even the sometimes highly dangerous ef- fects caused by their stinging hairs, differ from Pel- litory chiefly in their pistil-bearing flowers having a calyx of two sepals. Hops have not only a twining stem, and their pistil-bearing flowers collected in leafy heads, but are also known by having five stamens in each sterile flower, and the pistils and stamens on different plants. Finally, Hemp, which also belongs to the Nettle tribe, has the calyx of the pistil-bearing flowers slit on one side, two unequal styles, and five stamens in the sterile flowers. ‘The peculiar tenacity of the stems of Hemp is not uncommon in other plants of the same natural order, and may even be considered charac- teristic of it. Considering the many important purposes to which the Hemp is applied, and the prodigious strength that it possesses when twisted into ropes, you will probably be curious to know something of WOODY FIBRE. tsk the exact nature of the part which is capable of being converted to these great purposes. In that case you must have recourse to your microscope; be- neath which you may place a little tow, the threads of which are separated, and float in water. At first sight, with a weak magnifying-glass, you will discern no distinct organization in these threads; they will look like dark lines of about the thickness of a fine human hair; but if you bruise them and tear them about in the water with the point of a couple of needles, you will in time succeed in separating each of the threads into a very considerable number of exceedingly fine parts, which you may discern, by increasing the magnifying power of your microscope, to be transparent tubes, composed of a tough mem- brane, and tapering to each extremity like bristles ; these are glued together in bundles which constitute the finest threads that are visible to the naked eye. Their business is not simply to grow in the inside of a plant, in order that man may pull them out and ap- ply them to his own purposes; they have a far higher and more important office to fulfil. It is they which give strength and toughness to every part, and which enable the stem and the leaf to wave about in the breeze or to bend before the storm without breaking ; they are placed as a sort of sheath all round such tender parts as the spiral vessels, which are enabled within their safeguard to perform their delicate func- tions with certainty and security ; and, finally, it is they which act as so many water-pipes to convey the fluids of plants with rapidity from one part to‘ano- 52 LETTER Gu ther; up the wood, along the veins of the leaves to their extremest points, back again into the stem, and down the bark towards the roots. When plants have no woody fibre, they are universally so delicate and weak as to be unable either to raise themselves in the air, or to withstand any violence, as we see in mosses, lichens, mushrooms, and such plants. You will probably be surprised when I tell you that the ig TZree is so nearly the same in structure as the Nettle, that many Botanists consider it to belong to the same tribe; and you may possibly be tempted to exclaim with some who have not considered the subject very attentively, ‘‘ How absurd to place the Nettle and the Fig together in the same natural group!” J must admit that this does appear strange until the reason is pointed out; and I trust you will admit that itis clearly right when the reason shall have been explained to you. Let us then see what a Fig Tree is. It is an Exo- genous plant with leaves covered with very stiff short hairs, and with a pair of stipules at their base ; so isa Nettle. It has flowers with stamens and pistils sepa- rate: so has a Nettle ; its flowers have no corolla, and the pistil is a little simple body, which changes, when ripe, to a very small flat grain; all which is exactly what we find in the Nettle. In the essential parts of their structure the two plants then are alike. But where are the flowers of the Fig, you will inquire ; you can see nothing but a thick oval green body, which you know will turn to fruit, and which there- fore ought to be the flower; here, however, you must THE BREADFRUIT TRIBE. 153 again be prepared to meet with natural wonders. The thick oval green body is a hollow box, or recep- tacle ; within it in darkness and obscurity are reared the flowers, which, like the beggars’ children in the caverns among the fortifications of Lille, are so de- formed and pallid as hardly to be recognised. Cut a young fig open; the whole of its inside is bristling with sterile and fertile flowers, the former having five stamens, and the latter a jagged calyx, with a little white pistil sticking up in the midst of it. ‘This pistil, when ripe, becomes a flat round brown grain, which is lost among the pulp of the fleshy and juicy receptacle, where you eat it, and call it a seed. The difference then between the Nettle and the Fig Tree consists not in the structure of the stem, or of the leaves, or of the calyx, or stamens, or pistils, or fruit properly so called ; but in the hollow fleshy receptacle within which the flowers are forced to pass through their different stages. This kind of differ- ence is, however, of a very unimportant kind; and not greater than you find between the Strawberry and the Rose, about whose relation to each other every one is agreed. For these reasons, both the Fig and the Nettle are by some considered to belong to the same natural order; there is, however, a difference that I have not mentioned, and which is important; the juice of the nettle is watery, while that of the Fig is milky ; on which account other Botanists consider the Fig to be the representative of a natural order, distinct from that of the Nettle, but in the closest affinity with it. 154 LETTER XI. To this natural order belong the Breadfrwt tree (after which it 1s called the Breadfruit tribe), the Mulberry, and many other exotic trees. For their milkiness they are all most remarkable ; it is usually of a somewhat acrid nature, as you may find in the Fig itself; sometimes is highly poisonous as in the Upas tree of Java and some Indian species of Fig ; or is again quite harmless and even nutritious in the Cow tree of South America, to the trunks of which the Indians repair in the morning with their jugs and pails, just as the milkmaids of Europe to their cows. It is, however, probable that in this instance the milk is harmless only at a certain period of the year, before the venomous principle is formed ; for a West Indian plant called Brosimum, the young shoots of which afford a wholesome food for cattle, 1s very nearly the same as the Cow tree, and its old shoots are poisonous. ‘The Fig itself would not be fit to eat if gathered green, because at that time the fruit abounds in milk ; but when it is ripe all the milk has dispersed, and then only it becomes the wholesome fruit with which we are so well acquainted. Let this be a lesson to you never to judge hastily of the affinities of plants, but to remember that it is structure alone, and not vague external resemblances or differences by which their relations are determined botanically. The last of the tribes without corolla, which I shall be able to lay before you, is one that is constructed with still more simplicity than the last. They had at least a calyx, but this has neither calyx nor corolla, THE WILLOW TRIBE. 1535 nor any sort of covering to the stamens, beyond the seale-like bracts, out of the bosom of which the sta- mens or the pistils arise. ‘These plants are Poplars and Willows, which together form the Willow tribe (Plate XI. 2.). Their flowers grow in catkins (figs. 1 & 4.)—those beautiful silky bodies, glittering as it were with gold and silver, which are hailed by northern nations as the earliest harbingers of spring, and gathered for festivals under the name of Palms near London, and of gostlings in some part of Eng- land. The stamens are upon one plant, the pistils upon another. ‘The former are one, or two, or three, or five, or more, to each bract (figs. 2. & 3.); the latter are seated singly within a bract, and consist of an ovary, having one cell with many seeds, and a lobed stigma (fig. 5.). The fruit consists of hollow cases, which split into two valves (fig. 6.), and discharge a multitude of small seeds, covered with fine hair or wool (fig. 7.), like the seeds of the cotton plant. On these downy pinions the seeds will fly to great dis- tances and scatter themselves over the whole face of the country. The Willow is absolutely without any trace of calyx; the Poplar has a sort of membranous cup, which may be considered the rudiment of one. In taking leave of these imperfectly formed orders, I would recommend you to reduce their characters to an analytical form, in order to see their differences the more distinctly. You may do this in many ways, of which the following will serve as an example. Two of them have the sepals combined into a tubu- lar calyx, namely, the Protea and Marvel of Peru 156 LETTER XI; tribes; of which the former has hard leaves and stamens placed opposite the sepals, and the latter soft leaves, with the bottom of the calyx forming a bony covering to the ripe fruit. Two others have their male flowers arranged in catkins, namely the Oak and the Willow tribes, of which the former has closed fruit seated in an in- volucre or cup, and the latter opening fruit without any inyolucre. Finally, the three that are remaining, namely, the Amaranth, Nettle, and Breadfruit tribes, are at once known by the first having smooth leaves, without sti- pules, while the two last have rough or stinging leaves with stipules. These peculiarities may be expressed in a tabular form thus :— leaves hard, calyx all dropping off seu The Protea tribe. or withering away. Calyx ' tubular ) jeaves soft, calyx forming with its | The Marvel of Peru base a bony covering to the fruit tribe. i i6 rey an taveluere ¢ The Oak tribe flowers in in an involucre catkins 4 Aint wa eres : The Willow tribe. Calyx without an involucre not leaves smooth, ; tubular without stipules The Amaranth tribe. flowers not juice watery—The in catkins ( Nettle tribe. leaves rough, or stinging, with ” juice milky—The stipules Breadfruit tribe. Our next visit will be to far more beautiful subjects. 157 EXPLANATION OF PLATE XI. I. Tue Netrie Trisr.—l. A piece of Common Pellitory (Pa- rietaria officinalis).—2. The calyx of a sterile flower, with the sta- mens projecting.—3. The same cut open.—4. An anther.—5. A fertile flower.—6. A pistil.—7. An ovary cut through perpendicu- larly, shewing the position of the ovule-—8. A ripe fruit.—9. The same cut through perpendicularly, shewing the position of the embryo within the albumen.—10. An embryo. Il. Toe Wittow Trise.—l. A catkin of sterile flowers of the Monandrous Willow.—2. A single sterile flower of the Fellow Osier (Salix yitellina), with the gland, a, at its base.—3. The same with the bract that belongs to it.—4. A catkin of the fertile flowers of the Yellow Osier.—5. The pistil with its gland, a, and its bract, 6.— 6. A seed-vessel ejecting the seeds.—7. A seed with its down.— 8. A seed without the down.—9. An embryo with the cotyledons separated. LETTER XII. THE HEATH TRIBE—THE BINDWEED TRIBE. (Plate XII.) One Ler me now introduce you to an extremely beau- tiful set of plants, in which you will find nothing but the most charming colours, set off by so clear a com- plexion, and such perfect forms, that there is little comparable to them in the whole vegetable kingdom. Very different from the tribes we have lately seen, so far are they from wanting a corolla that they possess that part in a most highly expanded state; not, how- ever, consisting of several distinct petals,:as in all the natural orders we at first examined, but having the petals grown together into a cup or bell or hol- low body of some kind, and only separate at their upper ends. These corollas are technically named -monopetalous, or one-petaled ; a very bad designation because the corolla consists in reality of many petals in a united state; but the word was invented when the real nature of such a corolla was unknown, and custom has established what error first promulgated. It is to the various tribes of Monopetalous Dicotelydons that we are now to direct our attention. The Heath tribe, which iswhat I at first alluded to, stands pre-eminent among such plants for its love- SAE RLE e be Bred wee Vibes iE DAD Libri i> OF THE UNIVERSITY OF ILLINOIS THE HEATH TRIBE. 159 liness; and it is very easily known. We will say nothing about its leaves, firstly, because they are va- riable in appearance ; and, secondly, because it is now time we should leave off testing the Dicotyledonous character of a plant at every step; for you must by this time have begun to recognize, with certainty, the features of that primary class, without attention to its technical distinctions. It is in the flowers that the great peculiarities of the tribe are conspicuous. Let us take any Heath for an examination; that which I have at hand is the “ Hispid’ (Erica hispida), so called on account of the little stiffish hairs with which it is covered on every part. Like nearly the whole of the genus, it is a native of the Cape of Good Hope, where extensive tracts are covered with count- less species of all manner of forms and colours. ‘The Hispid Heath has a calyx of four sepals (Plate XII. 1. fig. 2. a); and a corolla looking like a hollow globe, with four short teeth at one end; it is of the clearest pink; you may see its veins through the skin, so transparent is every part; and their arrangement will reveal to you the fact of this hollow globe being in reality composed of four petals, so completely united at their edges that nothing but their points is to be distinguished. Arising from beneath the ovary, and perfectly sepa- rate from the corolla, are eight stamens ( fig. 3.), each of which has a slender filament, and a singular pur- ple anther, with two distinct lobes, shaped like the two prongs of a fork, and opening by a hole at their upper end. ‘This character of holes in the end of the 160 LETTER’ XH. anther is one of those that are essential to the Heath tribe. The ovary (fig. 6.) is a hairy body containing four cells and a great many ovules ; it is termimated by a style having a flat purple stigma, with four little projections on it, corresponding with the number of cells in the ovary. ‘This in time changes to a dry fruit that bursts into valves, for the escape of a count- less multitude of seeds as fine as grains of sand, they are frequently terminated by delicate crests or wings of different figures ( figs. 8. & 9.), and are beau- tiful microscopic objects. Now in this description you are to consider the hypogynous stamens, and the anthers with pores im them, as the most essential characters of the natural order, and they will, in fact, enable you to distinguish it from all others. It is principally in the breadth of the leaves, in the size and form of the flowers, in the texture of the fruit, and in the number of divisions of the corolla and stamens that the genera vary : they all agree in those common characters. For instance, the Ardutus is like a Heath, but it has broad leaves, ten stamens, and fleshy fruit, which gives rise to its common name of the Strawberry tree, and which renders it so noble an ornament of the romantic waters of Killarney. Andromeda again, with her countless blushing or snow-white flowers, and glossy or powdery evergreen leaves, is like the Arbutus, only the fruit is a dry capsule, opening by valves. Rhododendron and Azalea, on the contrary, have THE BINDWEED TRIBE. 161 corollas that spread open at the mouth, with unequal divisions, and with stamens bent towards one side ; while Kalmia has cup-shaped corollas with ten little niches in which the anthers are nipped up, so that when the flower expands, the filaments are all curved downwards away from the pistil, as if the corolla was unwilling to allow them to touch it; but stir the filament with a pin, at the time when the anther is ready to shed its pollen, and in an instant the stamen starts up, and approaches the anther to the stigma. All these plants are so well known, from being the pride of the American garden, that I have only to name them to recall them to your memory. Considering how very handsome they are, and how innocent is their aspect, you would scarcely sup- pose that venom lurked beneath their charms ; they will, however, serve as an instance of how little you may trust to appearances, even among flowers; for both the Rhododendron, the Kalmia, and the An- dromeda, have not only noxious leaves and branches, but their very honey is poison; as has been too fatally experienced by those who have fed of the produce of the hives of Trebizonde. Extremely different from these is the tribe of Bind- weeds (Plate XII. 2.), of which the wild Convolvulus, at once the pride and pest of our English hedges, and the not less beautiful but more harmless Jpomea of the gardens are the representatives. These plants, like the Heath tribe, are monopetalous, but they have a twining stem, and corollas that are neatly plaited M 162 LETTER XIt. when they close, like the paper purses that are made for children. These corollas open and close under the influence of light or darkness, some opening only in the day, others only in the night, and in one case (Ipomoea sensitiva) they are so sensitive, that they contract beneath the touch like the leaves of the Mimosa. ‘The calyx of the Bindweed consists of five sepals, which overlie each other so sompletely, that you can seldom perceive more than the two outermost. The fruit (fig. 5.) contains three or four cells, and a very small number of seeds, the embryo of which ( fig. 7.) is doubled up in the most curious way, just as if there were not room enough within the seed for it to grow. The roots of many of them are large and fleshy ; they possess powerful medicinal properties, and are fit for food only in the case of the Sweet Potatoe (Convolvulus Batatas), which was so much esteemed before the common Potatoe displaced it in Europe. To this tribe also belongs an odd little plant called Dodder (Cuscuta). Have you never remarked upon the stems of the Heath, or Nettles, or of the Furze, clusters of stout reddish cords which are so twisted and intertwined that you would take them for a knot of young snakes, if the colour first, and then their touch did not undeceive you. If ever you have ob- served so strange an appearance you have seen Dodder, which, originally earth-born, soon lays hold of some neighbouring plant, twists her leafless shoots around it, fixes them firmly to the branches, quits her hold of the soil, and thenceforward, as if ashamed of THE BINDWEED TRIBE. 163 her humble origin, feeds only upon dews and rain, till the frost comes, nips her tender frame, and leaves her dead and shrivelled form still clinging to its place : a monument of the punishment of vegetable ambi- tion. ‘This strange plant is of the Bindweed tribe ; but is extremely imperfect; leaves it has none, except a few stunted scales, and its flowers are little white things collected in close clusters. The fruit consists of membranous capsules, in each of which are two cells and four seeds. I must now leave you to hunt for Dodder, and to study her singular habits if you can find her, till I have leisure to resume my pen. EXPLANATION OF PLATE XII. I, Tae Heatu Trise.—l. A shoot of Hispid Heath (Erica hispida).—2. A flower; a, the sepals.—3. The stamens and pistil—4. and 5 anthers.—6. A pistil cut open, shewing the arrangement of the ovules within the ovary.—7. The ripe fruit of Rhododendron, natural size; a, a central receptacle of seeds, from which the valves separate. —8. A seed very highly magnified; a, the hilum, or scar where the seed separated from the receptacle——9. The same cut through per- pendicularly, shewing the embryo lying in the midst of albumen. I]. Tae Brnpweep Trise.—1. A shoot of Dwarf Convolvulus (Convolvulus tricolor).—2. The stigma.—3. A stamen.—4. The ovary divided perpendicularly, shewing the manner in which the ovules grow.—5. The ripe fruit.—6. A seed.—7. The same cut through perpendicularly; a, the radicle of the embryo ; 4, the hilum, or scar where the seed separated from the receptacle. M2 LETTER XIII. THE GENTIAN TRIBE—THE OLIVE TRIBE— THE JASMINE TRIBE. (Plate XIII.) Ir there is any one tribe of plants in nature, the colours of whose flowers are more intensely vivid, and the foliage neater, and the whole aspect prettier than any other, it is that which comprehends the different species of Centaury, and the beautiful Alpine Gentians with their flowers of azure or yellow, ‘This which is called the Gentian tribe, belongs to the Mono- petalous division of Dicotyledonous plants, among which it is usually known by the leaves, which are opposite each other on the stem, being ribbed (that is, having two, or four, or more strong veins parallel with the midrib), and extremely bitter. The flowers are also constructed upon a peculiar plan. The calyx consists of four or five sepals more or less united, the corolla has the plaited appearance that I mentioned in the Bindweeds, with all its divisions equal to each other ; there are four or five stamens, and a superior ovary, with two many-seeded cells, and a two-lobed stigma. All this you will find in the Gentianella (Gentiana c _ LIBRARY OFTHE =: UNIVERSITY OF ILLINOIS THE GENTIAN TRIBE. 165 acaulis, Plate XIII. 1.), a plant that you can- not fail to procure from the first good garden you enter. It indicates the presence of the bitter sto- machic qualities for which the Gentian of the shops is so much employed, and you may be quite sure that they exist in any wild species in which a similar structure is discoverable. Thus we have in our marshes what is called the Calathian Violet (Gentiana Pneumonanthe), with narrow leaves, and a corolla greenish externally, but a lovely azure within; and on our hills, or sea-cliffs, a branchy dwarf plant with rose-coloured blossoms (Erythrza Centaurium), called Centaury ; in both these the same bitterness occurs, and they both may be used just as well for domestic bitters as the exotic drug of the shops. The Gentian tribe is not a very extensive one; the principal part of it is met with in the tropical coun- tries of South America ; a few species, called Chironias, from the Cape of Good Hope, exist in green-houses ; another group, of almost uncultivable habits but great beauty, called Sabbatias, is found in North America; and the remainder, which are chiefly Gentians, are found all over the milder and more alpine parts of Europe and Asia; in the Swiss Alps, on Caucasus, and on the Himalayan mountains of India, they enamel the sward with blossoms of such intense brilliancy, that the eye can scarcely rest upon them. From some unexplained cause the plants of this tribe are generally so difficult to manage in England, that with the exception of three or four robust species, 166 LETTER XIII. the most skilful gardeners cannot keep them alive : were it otherwise, there are none which it would be so easy and so desirable to procure from foreign countries. Brief as my remarks upon this tribe have been, you will find that they are sufficient to enable you to recognize it. Let me now turn to another. It is a very unusual circumstance for monopetalous plants to have only two stamens, unless the corolla is irregular: that is to say, unless the parts of the corolla are of unequal size. ‘There are, however, two natural orders of which the essential character consists in the presence of two stamens within a regular corolla. Of these the Olive tribe is the more remarkable, and that which I shall take for illustration. The Olive itself is so uncommon in England, that it will be more convenient to select the Privet for the plant by which your notions of the tribe are to be formed. The Prwet is a Dicotyledonous shrub, with opposite leaves. Its calyx is a four-toothed cup: being com- posed of four sepals united, except just at the tips (Plate XIII. 2. fig. 4.). The corolla consists of four equal petals, united half-way into a tube (fig. 1.), and joining, before they expand, by their edges only. The stamens are two, of a very common appearance. The ovary is superior, and contains two cavities, from the top of each of which hang two ovules (fig. 5. & 6.); it is terminated by rather a thick style, and a two- lobed stigma. To this succeeds a small round black succulent fruit (fig. 7. & 8.), which usually contains but one seed. This is all that you find im any others of THE OLIVE TRIBE. 107 the Olive tribe, the organization of whose flowers is remarkably uniform. For example, the Olive has a shorter corolla and a hard bony nut in its fruit; the Phillyrea, with its beautiful deep-green leaves, is exactly like the Olive in the structure of its fructification, but its nut 1s brittle instead of bony; and the fragrant Lilac (Syringa) differs from all these in its longer corollas, and in its fruit being dry, and splitting mto two valves. Simple as is the character of the Olive tribe, and uniform as the genera usually are in their structure, there is one most remarkable exception, which I should not omit to notice. The Ash (Fraxinus), which you know by its smooth and graceful trunk, and by the airy appearance of its light and elegant foliage, is a plant without any corolla, and yet it belongs to the Olive tribe. It may seem exceedingly strange that a plant which has no corolla should be classed with those which have a perfect monopetalous one, and if such a thing were to happen in an artificial system it would be extremely improper, but in a natural ar- rangement all sengle characters are subordinate to the mass of characters, and, when they do not accord with the usual structure, form exceptions to general rules. Thus, as the Ash agrees with the Olive tribe in every character except the absence of the corolla; that absence is only reckoned an exception to the general fact that the Olive tribe has a monopetalous corolla. It happens that we possess a striking proof, beyond what the fructification affords, that the Ash and Olive 168 LETTER XIII. are both very nearly related to each other. It is well known that no tree can be either budded or grafted upon another, unless they are extremely nearly related by natural ties; the Olive may be grafted upon the Ash, and consequently the inference that is drawn from the construction of the flowers is confirmed by the physical properties of the two plants. I told you but a short time since that there were two monopetalous natural orders with regular flowers, in which there are only two stamens. The one to which as yet no allusion has been made, is the Jasmine tribe, to which belong the many fragrant plants which bear that name. These are known by a most simple character from the Olive tribe; the edges of the divisions of their corolla, instead of being exactly fitted to each other before the flowers ex- pand, overlie each other m the bud, and slide off each other when they unfold. These differences give rise to two technical expressions which I cannot do better than explain to you on the present occa- sion. We call the manner in which the parts of the flower are folded up in the bud the estivation ; and we apply the term either to the calyx or corolla, or stamens, or pistils, with some qualifying adjective. When two parts are placed together, edge to edge, so that one does not lie at all upon the other, those parts are said to be valvate, and when they do lie upon each other, they are said to be imbricated, or tiled, im al- lusion to the manner in which tiles (called in Latin imbrices) are placed upon the roof of a house. These 169 terms are frequently coupled in speaking of the corolla: of which the Olive and Jasmine tribes afford a striking example. The former is said to have a valvate estivation, the latter an imbricated estivation. EXPLANATION OF PLATE XIII. I. Toe Gentian Trise.—A plant of Gentianella (Gentiana acaulis).—1. The lower part of a corolla, with the five stamens at- tached to it.—2. A pistil—3. An anther.—4. A ripe fruit dividing into two valves a, and invested with the withered remains of the calyx and corolla. II. Toe Oxive Trise.—l. A flower of the Privet (Ligustrum vulgare).—2. The face of an anther.—3. The back of one-—4. A calyx with its pistil—®5. The same cut through perpendicularly, shewing the ovules hanging in the cells of the ovary.—6. A horizon- tal section of the same.—7. A cluster of ripe berries.—8. A fruit eut through, with a view of the single seed and the embryo within it; a the second cell, which is nearly obliterated by the pressure of the seed upon it.—9. A seed extracted from the pulp.—10. The same cut across.—11. The embryo taken out. LETTER XIV. THE HARE-BELL TRIBE—THE LOBELIA TRIBE—THE HONEYSUCKLE TRIBE—THE COFFEE TRIBE. rene (Plate XIV.) From the Olives of Italy, with their dingy foliage, and imperishable wood, let us turn to our own innocent native Hare-bells, whose modest beauty amply recom- penses us for the absence of the gaudy, scented, and often venomous flowers of more southern climates. In this plant we find the representative of an exten- sive natural order, the species of which are scattered over all Europe and the cooler parts of Asia and America, dwelling in dells and dingles, by the banks of rivers, in shady groves, on the sides of mountains, and even on the summit of the lower Alps, where the last lingering traces of vegetation struggle with an atmosphere that neither plant nor animal can well endure. We know the Hare-bell tribe only in its humblest state, bedecked with no other ornament than a few blue or purple nodding flowers; but in foreign countries, it acquires a far more striking appearance. On the mountains of Switzerland, there are species with corollas of pale yellow, spotted with black; on a AES eS Fics LE tokls Ade 2 — AL OPP ELST Money stich. LIBRARY OF THE UNIVERSITY OF iLLINGT THE HARE-BELL TRIBE. 171 the Alps of India are others of the deepest purple that can be conceived: on the rocks of Madeira lives one which was formerly not uncommon in our gar- dens (Musschia aurea), whose corollas are of a rich golden yellow ; and finally, in the pastures of the Cape of Good Hope are Roellas, the flowers of which are elegantly banded with streaks of violet or rose passing into white. Let us, however, confine ourselves, in the first in- stance, to the true Hare-bell genus. In every shady lane there grows a diminutive herb, with little grassy leaves, and a few blue bell-shaped nodding flowers ; this is the real Hare-bell, which Botanists call the xound- leaved Campanula ; you will wonder why it is so called, since its leaves are narrow, like those of a grass; but if you pull it up by its roots, you will then find that the lowest of all the leaves have a roundish outline, from which circumstance it derives its name. You who live in the country will take this species for ex- amination; but I am obliged to step into a garden for a subject, and I have selected a species found in thickets in the Ukraine, from which it is named Campanula ucranica; either will answer the purpose equally well. The calyx of the plant has five deep divisions (Plate XIV. 1.), which spread regularly away from the base of the corolla, and from the top of the ovary. The corolla has very regularly the figure of a bell, except that it is too narrow at the base ; its borders is divided into five lobes, which shew that it is made up of five petals, and it is veined in a pretty and L772 LETTER XIV. peculiar manner. From the base of the corolla, and consequently from the summit of the ovary, spring five stamens (fig. 1.), whose filaments are broad, firm, and fringed (fig. 2.), curving inwards at the base, and bending over the top of the ovary, as if to guard it from injury; their points touch the style, and keep the anthers parallel, and in contact with it, till they shrivel up and fall back, which happens immediately after the flower unfolds. The style is a taper stiff column, about the length of the corolla, and longer than the stamens. It is covered all over, up to the very tips of the stigma, with stiff hairs (fig. 4.) which nature has provided to sweep the pollen out of the cells of the anthers, as the style passes through them in lengthening; if it were not for this simple but effectual contrivance, as the anthers burst as soon as ever the corolla opens, their pollen would drop out of the nodding flowers and be lost before the stigma was expanded and ready to receive the ferti- lizing influence; the hairs of the style catch the pollen and keep it till insects, wind, or accident brush it down upon the inverted stigmas. Next let us look at the ovary. ‘This organ is in the Hare-bell a case containing three cavities or cells (fig. 3.), surrounding a central axis; im each cell there is a large fleshy receptacle, over which is spread a multitude of ovules. After the stigma is fertilized, the corolla and the stamens drop off, the sepals harden, enlarge, and collapse, all the parts become browner and thicker, stout ribs appear im the substance of the ovary, which droops still more than THE HARE-BELL TRIBE. 173 the flower itself ( fig. 5.), and at last a general dryness, hardness, and brownness, announce that the ripening of the fruit is accomplished. But how are the dust- like seeds ever to find their way out of this lidless box, or to penetrate its tough sides? Considering what happens in so many other plants, we should natu- rally expect that it would take place by a separation of the edges of the three carpels into valves, near their points; but upon looking at the top of the ovary between the sepals, we find that part still tougher than the sides, and without the slightest ap- pearance of an opening. It is by a rending of the thinnest part of the sides of the fruit, in the fork of the three principal ribs (fig. 5. a.), that these valves are produced, and that nature provides for | the escape of the seeds; the rending takes place upon the final drying of the sides of the fruit, when every part becomes stretched so tight, that any weak portion must of necessity give way. As the stretching takes place with uniformity, and as the skin at the forks of the ribs 1s always more tender than any other part, the opening of the valves will consequently occur with the same invariable certainty as the formation of the seeds. Do not, however, suppose that this curious contri- vance is characteristic of the Hare-bell tribe: on the contrary, it is only characteristic of the Hare-bell genus ; for in other genera, the fruit opens by-a sepa- ration of the points of the carpels in the usual way ; the tension of the sides consequently does not take place, and no lateral openings being necessary, none are ever formed. 174 LETTER XIV. Among the commoner genera, allied to the Hare- bell, should be distinguished Phyteuma, some very pretty species of which are found on the Alps of Europe, and two, even in hedges in the south of England, although very rarely ; this genus is known from the Hare-bell by its corolla not being bell-shaped, but split into five very long and narrow segments. Wahlenbergia also, with the corolla of a Hare-bell, but with the fruit opening at the points, is found in the damp groves of Cornwall and Devonshire, in the shape of a charming little ivy-leaved plant, creeping among the turf, above which it raises its blueish drooping bells (Wahlenbergia hederacea) ; and finally in corn-fields, often enamelling the stubble im harvest time, appears the hybrid Looking-glass flower (Specularia hybrida), the corolla of which spreads flat round the stamens, forming little rays with its petals ; its fruit sheds its seeds through three slits in its angles. The Hare-bell tribe is as harmless as it is beau- tiful; the roots of some species are eaten under the name of Rampion, the leaves of others are used in Salads, and the bells afford an abundant supply of honey to the bee. ‘The stems and roots abound in a milky juice, which although in this case innoxious, is usually a symptom of poisonous properties, and which, in a neighbouring tribe, indicates the pre- sence of the most fearful venom. As the gardens contain many species of the deleterious group, called _the Lobelia tribe, I cannot do better than take this opportunity of explainmg to you how you may know them. Imagine a Hare-bell with its corolla split mto an THE HONEYSUCKLE TRIBE. P75 irregular form, and its anthers grown together into a cylinder through which the stigma projects, and you will have a Lobelia, many of the species of which, such as L. Cardinalis, fulgens and splendens, are the admiration of gardeners, on account of their velvety scarlet flowers. Put not your faith in these, for they are all acrid in the most intense degree, and fatal alike to animals and man. ‘They are very common in tropical countries, and are chiefly American; some of them are herbs like those we see in the gardens, others are bushes, or even small trees. Two of the rarest of British plants are the burning Lobelia (L. urens) of Devonshire, and the water Lobelia (L. Dortmanna), which inhabits the very bottom of moun- tainous or northern lakes. Resembling the Hare-bell tribe in its inferior ovary, but far different in its essential characters, is the tribe which takes its name from the Honeysuckle. ‘To understand the structure of this, you cannot do better than study the Honeysuckle itself (Plate XIV. 2.). The leaves of that plant are placed opposite each other with great uniformity ; the uppermost even grow together at their base ; im no case do you find even a trace of stipules, or any thing like them; a material point, which I must beg you to remark. The flowers have a roundish green inferior ovary (fig. 1. a.), terminated by a very minute five-toothed calyx, and containing three cells (fig. 3.), in each of which hang two or three ovules. The corolla is a tube, the end of which divides into two lips (fig. 1.), one of which is narrow and undivided, the other cut 176 LETTER XIy. into four rounded lobes: in reality, it 1s composed of five petals, one of which is separate for about a quarter of its length, and constitutes the undivided lip, while the other four are united nearly to their very points, and form the upper lip. Five stamens arise from the tube of the corolla; the style is long and thread- shaped, and ends in a pin-headed stigma. ‘The fruit is a succulent berry, containing one or two bony seeds ( fig. 6.). Such is the Honeysuckle, the essence of whose character, consisting in having an inferior, many- celled, few-seeded ovary, and monopetalous flowers, is found in Symphoria, one of whose species bears balls of snow-white fruit, whence it has gained the name of Snow-berry ; and in the St. Peter’s Wort (Diervilla), the fruit of which is dry and tapering. It is here also that is stationed the interesting Linnea borealis, with its delicate rosy bells, and creeping stems; by which it is said that the humble and neglected fate and early maturity of the great Swedish naturalist, whose name it bears, were typified, at the time it received its modern title. Do not imagine that because the Honeysuckle twines, and Linnea trails, all the tribes are twiners, or trailers. On the contrary, if you are acquainted with either the Snow-berry or the St. Peter’s Wort, already mentioned, or with the Zartarian and Fly Honeysuchles of the gardens, you will already be aware that many species are upright branching bushes. This is more particularly the case with some other genera. The Elder, of which I long THE COFFEE TRIBE. 177 since gave you a description (page 35), warning you not to mistake it for an Umbelliferous plant, belongs to the Honeysuckle tribe; and so do the Wayfaring tree (Viburnum Lantana), and the Guelder Rose (Viburnum Opulus), both of which are to be met with in every shrubbery. At first sight, these plants seem to be unlike the Honeysuckle, but study their struc- ture carefully, remembering what it is that I have told you is essential to the tribe, and you cannot mistake their affinity. In fact, if they were twining you would never have doubted it. In North America there grows a plant of this tribe with broad leaves, clusters of flowers sitting close in their bosom, and yellow berries, called ‘Triosteum perfoliatum, the seeds of which have proved the best of all substitutes for Coffee. Knowing nothing of the latter plant, you cannot have suspected that it was in any way allied to the Honeysuckles; but the fact I have now mentioned may excite a suspicion that it may be so, as in reality it is. Coffee (Coffea Arabica), the infusion of whose seeds forms the beverage which is probably the most universally grateful of all that the luxury of man has prepared, belongs to a very extensive natural order, almost confined to the warmer parts of the world, comprehending the meanest weeds and the most noble flowering trees, obscure herbs with blos- soms that it almost requires a microscope to detect, and bushes whose scarlet corollas are many inches long ; and producing drugs invaluable to man for their important medicinal properties. Ipecacuanha, N 178 LETTER XIV. Coffee, and various kinds of fever barks, especially that of Peru, are among its useful products. Now, if you gave the Honeysuckle tribe well defined stipules at the base of the leaves, you would convert them into plants of the Coffee tribe ; for, notwithstanding many other differences in particular instances, the two natural orders, viewed in a general manner, can hardly be said to be absolutely distinguishable by any other character. I would, therefore, recommend you to take this as the true distinction, and not to trouble yourself about further differences, unless you intend to study Botany minutely. Coffee itself consists of the seeds of the plant, divested of their skins, and of a dark purple fleshy rind that enveloped them. They are formed almost entirely of albumen, in the base of which a very small embryo is placed. A seed of any commom Honeysuckle (figs. 6. & 7. Plate XIV. 2.) will shew you this; for, in all that regards the seed, the Coffee tribe and the Honey- suckles agree. I have said that Triosteum has proved the best of all substitutes for Coffee; a circumstance that will not now surprise you; but it is probable that other plants of either the Honeysuckle or Coffee tribes, would answer the purpose equally well, pro- vided their seeds are large enough, and their albumen of a hard horny texture. 179 EXPLANATION OF PLATE XIV. I. Toe Hare-sett Trise.—A few flowers of the Ukraine Hare- bell (Campanula ucranica).—1. The ovary a, with the stamens and style, in the state in which they are found after the corolla has ex- panded.—2. A stamen with its broad thick base.—3. A horizontal section of the ovary, shewing the three cells and many seeds.—4. A view of the hairy style and stigma, before the lobes of the latter sepa- rate.—5. Aripe fruit; a, the holes through which the seeds escape. —6. A seed.—7. The same cut perpendicularly, shewing the embryo. Il. Tae Honeysuckie Tripe.—A piece of the Minorca Honey- suckle (Caprifolium implexum).—1. A flower, with the inferior ovary. —2. An anther, with the upper end of the filament.—3. A horizontal section of an ovary, with the three cells, and the ovules cut through as they hung in them.—4. A perpendicular section of an ovary, shew- ing how the ovules hang from the top of the cavity.—). A little cluster of fruit.—6. A seed.—7. The same cut through perpendicu- larly, shewing the embryo. LETTER XV. THE BORAGE TRIBE—THE NIGHTSHADE TRIBE— THE PRIMROSE TRIBE, (Plate XV.) ORAL LLL DOL ILS I nore that you will have found the distinguishing characters of all the Monopetalous orders we have examined up to this time sufficiently clear and defi- nite to be understood and remembered; and that as I have been proceeding, you have been analysing their distinctions after the plan of which some instances have been already given you. Tor I am convinced by long experience that this is the only sure way of fixing such matters in the memory. As it is my In- tention, after we shall have gone through the whole of them, to analyse for you such of the Monopetalous orders as I may select for illustration, it is unnecessary for me to dwell as yet upon their mutual distinctions. Let us, on the contrary, proceed, for the present, steadily in our examination of other natural orders. Of all the groups into which Botanists have di- vided the Vegetable Kingdom, there 1s none which combines uniformity of general appearance with similarity in structure in a greater degree than those rough-leavyed plants, which Linnzus used, on Or Ge Of ay She Lorage Aube Black Nughlshade LIBRARY. OF [Ht Aer see weft ELF THE BORAGE TRIBE. 181 that account, to call Asperifoliz, and which we know by the name of the Borage tribe. Leaves covered with rigid hairs, a regular monopetalous corolla, and a four-lobed ovary, which changes into four seed- like grains, form the peculiar character of this natu- ral order, of which the Violet Alkanet (Anchusa ita- lica) isa common and good illustration. In Botanic gardens, or in collections of biennial plants, this is an extremely common plant, so that I anticipate no difficulty in your procuring it. Should you, how- ever, be unable to procure it when this letter reaches you, take a shoot of Morget-me-not, by which you may also follow me. My reason for selecting the Alkanet, is the large size of all its parts of fructifi- cation. The leaves of this plant have a fleshy texture and a mucilaginous pulp; but their skin is covered with hairs so stiff and sharp that they will prick the fingers if drawn over them against the hairs. A miscroscope will shew you that this is owing not so much to the stiffness of the hairs themselves, as to a hard stony base from which they arise, and which if your magnifying power is strong enough, will be found to consist of a cluster of very hard cells of cellular tissue. When the leaves are young, this hardness is less remarkable ; but as they grow old, it becomes very conspicuous. ‘The leaves are placed alternately on the stem, and the latter is round—two facts which I will beg you to recollect. The flowers are arranged in a singular manner. The stalk which bears them is coiled up (Plate XV. 1.) 182 LETTER XV. at the point, so that the youngest flowers are quite hidden by its folds; but it gradually uncoils as the flowers expand, till at last it becomes nearly straight. In consequence of this singular arrangement, the flowers are all forced towards one side, and when they are expanded, look as if they actually grew from one side only ; this, however, is not the fact—they are only turned towards one side. I think I have al- ready explained to you that we call the arrangement of the flowers upon their common stalk the wmfto- rescence ; and that different adjectives are added to this word to explain its nature. Thus, in Umbellife- rous plants, the inflorescence was umbelled; in the Borage tribe it is what is called gyrate; a fine word expressive of being coiled. Now this gyrate inflorescence will of itself enable you to recognise the Borage tribe, and the families most immediately allied to it, without recourse to any thing further. The calyx, which is covered with hairs, like the leaves, consist of five sepals jomed to each other more than half way, so as to form a tube (jig. 2.). The corolla has its border divided into five lobes, opposite which, at their base, are five hairy convex scales, which converge and close over the mouth of the tube, so as effectually to prevent any intruder from entering it (fig. 1.). From the side of the tube of the corolla, below the scales, spring five stamens, which sit close upon its surface, without any visible filament. The ovary is divided into four deep lobes (fig. 3.), from the middle of which rises a taper style, terminating in a double stigma. THE BORAGE TRIBE. 183 When the fruit is ripe it is invested with the calyx, which remains green for a long time (fig. 4.), only contracting at the point, so as to cover the fruit. Cor- responding with the four lobes of the ovary, are four grains, or rather rugged bony nuts (fig. 5.), which finally separate from each other, when they look like so many seeds, for which they used to be mistaken. These, along with the gyrate inflorescence, are the great characters of the Borage tribe, as distinguished from all other Monopetalous Natural Orders. Many of the genera of the Borage tribe are ex- tremely common. The most beautiful of all our wild flowers, Viper’s Bugloss (ichium vulgare), is one of them. It is known by its corolla having an unequal and irregular margin, and a sort of bell-shaped figure. ‘The deep red or purple spots and hairs of that plant are very remarkable. Then there is Forget-me-not (Myosotis), whose various species ornament ditches and dry banks with their pretty blue blossoms. It is known from Alka- net only by the scales of the mouth of its corolla being more rounded and shorter. Borage, too (Borago officinalis), occasionally makes its appearance upon banks, and in waste places; it is conspicuous for its azure flowers, whose corolla is deeply divided into five spreading lobes, which are much longer than the tube. Besides these, we have Hound’s-tongue (Cynoglos- sum), with long grey leaves, and dingy reddish brown flowers, succeeded by broad fruit, covered all over with stiff hooks ; Zungwort (Pulmonaria), with leaves 184 LETTER. XV; spotted with green and white, and flowers of a lovely blue, shaped like a funnel; the mean-looking Grom- well (Lithospermum), which seems as if conscious of its worthlessness, by constantly dwelling with weeds and rubbish; whose very fruit is so like a stone, that it derives its Botanical name (Lithospermum signifies literally stone-seed,) from that circumstance; and finally Comfrey (Symphytum), with tall coarse stems, and tubular flowers, the scales of whose mouth seem as if made expressly to teach us what the real nature of those singular parts are in other genera. In the Comfrey, the scales are so exactly like the filaments, that if you cut off the anthers, you can- not tell one from the other; and consequently, as all other circumstances confirm the opinion of their being abortive stamens, the scales are so con- sidered. Not one of the Borage tribe is otherwise than harm- less; the young shoots of Comfrey have even been eaten as Asparagus, but they have too little taste to be worth cultivation; and Borage itself was once an ingredient in a favourite beverage of our forefathers, called a cool tankard. It is however for their dyeing properties that they are really valuable. The dye called Alkanet, or others of a similar quality, is fur- nished by the roots of Anchusa timctoria, Lithosper- mum tinctorium, Onosma echioides, and several other species. From this harmless natural order, let us turn to one, the properties of which are too often dangerous. Henbane, Nightshade, and ‘Tobacco, the narcotic THE NIGHTSHADE TRIBE. 185 Thorn-apple, with the half fabulous Mandrake, whose roots were said to shriek as they were torn from the earth to give effect to magical incantations, form, with a number of other plants, a large natural order, the prevailing quality of which is to be poison- ous. Many of them are common wild plants, and none more so than the species called black Night- shade (Solanum nigrum), which is sure to spring up wherever a spot of ground is neglected, and suffered to become waste. It is to this plant I shall trust for explaining the general character of the Night- shade tribe. Black Nightshade is a plant with broadly lance- shaped leaves, slightly toothed at the edge, and seated alternately upon the stem (Plate XV. 2.). Its flowers consist of a short five-toothed calyx, of a mo- nopetalous corolla, with five equal divisions (fig. 1.), of five equal stamens, and of an ovary (fig. 2**.) with two cells, in each of which is a number of ovules. The style of the ovary is thick and shagey at the bottom, and terminated by a thickened undi- vided stigma. The fruit is a small black berry, containing two cells, and a number of yellowish seeds, whose skin is covered closely with little pits (fig. 4.) ; inthe inside is an embryo, which is coiled up upon itself in the middle of a quantity of fleshy albumen (fig. 5.). Of these characters, the most es- sential ones are the superior ovary with two cells, the regular flower, and the alternate leaves. ‘The last point distinguishes the Nightshade tribe from the Gen- tians, and you will find, by and bye, that the two 186 LETTER XV. former separate it from other orders you have still to examine. The genus Solanum is known in its tribe by the anthers opening by two holes or pores at their points (fig. 1. a.); besides Black Nightshade, it contains the itter-sweet (S. Dulcamara), whose red and tempt- ing berries present a dangerous decoy to children ; the Love Apple (S. Lycopersicum), or Tomato, the pulp of which is so much esteemed in sauces; the Egg-plant, or Aubergine (S. Melongena), whose fruit, when fried in slices, forms a delicacy in French cook- ery; and above all, the Potatoe (S. tuberosum). Here, you will imagine, is a singular assortment of eatable and poisonous plants in the same genus ;_ but in truth, the fruit of these is in all cases deleterious till it is cooked; ‘Tomatoes are stewed, Ege-plants are washed and fried before they are eaten, and it is not to be doubted that they would all prove mju- rious, if used in araw state. The fruit of the Potatoe is notoriously unwholesome ; and if its roots are not so, that circumstance is to be ascribed in part to their being cooked, and in part to their being composed almost entirely of a substance like flour, which in no plant is poisonous, if it can be separated either by heat or by washing, from the watery or pulpy matter it may lie among. Deadly Nightshade (Atropa Belladonna) belongs to a genus resembling the last in its berries, but hav- ing a bell-shaped flower, and anthers which open by slits in the usual way. ‘he fruit of this plant is the most venomous of all our wild berries ; it is of a deep THE NIGHTSHADE TRIBE. 187 shining black, and follows a livid brown corolla. The Mandrake is aspecies of the same genus (Atropa Madragora), but it has whitish flowers veined with purple; and scarcely any stems; it is only found in the southern parts of Europe. Henbane (Hyoscyamus niger) lives on commons, especially where the soil is chalky, near old cities and upon banks. Its broad pale leaves have a fetid smell, are irregularly lobed at the edges, and are covered all over with greasy hairs. ‘The flower sits close upon the stem, and have a large dirty-yellow corolla, veined with brownish purple, which gives them a peculiar livid appearance. The Thorn-apple (Datura Stramonium), so cele- brated for its narcotic properties, is distinguished by its fruit being dry and covered with stiff spines; and Tobacco (Nicotiana Tabacum) by its long tubular corolla and smooth dry fruit bursting into two valves. To enumerate any greater number of these delete- rious plants would be to occupy a larger space than I have room for; what I have already mentioned will suffice to make you understand their general nature ; and for the rest you must consult systematic works. All that I beg you to recollect is, that plants of the Nightshade tribe, are not only monopetalous, but have a superior two-celled ovary, regular 5-lobed flowers, and alternate leaves. ‘The fruit of all such avoid, until it has been ascertained by the experience of others, that they can be eaten with safety. You will scarcely suspect that those prettiest of | spring flowers, Primroses, Oxlips, and Cowslips, can be ad 188 LETTER XV. in any way related to the venomous plants I have just mentioned; nor do they in fact belong to the same tribe ; but they are so similar in many respects that I shall have no opportunity more fitting than the present, to say a word to you about them. Endeared as they are to us all by some of the sweetest recollec- tions of infancy, it would almost amount to a crime to pass them by with neglect. Like the Nightshade tribe they have regular monopetalous flowers with five stamens, and a superior ovary; they are some- times similar in habit, as in the case of the Mandrake, which resembles a gigantic Primrose with white flowers marked by purple veins, and they also possess slight narcotic properties. ‘They are distinguished by one circumstance in particular, by which they may be at all times known among our wild flowers with certainty,—their stamens are not placed between the lobes of the corolla, as in the Nightshade tribe, but are opposite to them, a very curious and permanent difference. This you will instantly discover by the examination of the Primrose, the Auricula, or the Polyanthus. The ovary is also constructed on a different plan : you will find that of the Primrose to contain only one cell, with the ovules collected in the centre: in the Nightshade tribe there are two cells; on the outside of the ovary of the latter, you will discover two fur- rows on opposite sides of it, indicating that it is con- stituted by the growing together of a pair of carpels : on the outside of the ovary of the Primrose are five furrows, slight indeed, but sufficiently apparent, and THE PRIMROSE TRIBE. 189 indicating its formation out of five carpels. The pe- culiarity in the stamens is, however, sufficient without referring to the fruit, except when the corolla has fallen off. With this character agree the beautiful pigmy Alpine plants called Aretia and Androsace ; here also are referred Soldanella with its little bells of blue so prettily notched on the border and Cyclamen or Sow-bread, whose fruit is forced, by the rigid coiling up of the flower-stalk, down upon the earth, where it lies concealed by the broad ivy-like leaves. Here too are arranged the Pimpernel (Anagallis), one of whose species is called the Poor Man’s Weather-glass, because it 1s found in every piece of waste ground, and will only open its tiny brick-red flowers in fine weather, closing them at the approach of rain; and Loosestrife (Lysimachia), whose creeping stems, little yellowish-green leaves, and brilliant yellow flowers are the brightest ornaments of the moss and short herbage that springs up in woods and shady places. Interesting as are the British species of this natural order, they are far inferior in beauty to their relations which live on the mountains of other countries : for the Primrose tribe most frequently prefers Alpine stations to all others. It is in the higher regions of the mountains of Switzerland and Germany, on the Pyrenees, and upon those stupendous ridges, from which the traveller beholds the vast plains of India stretching at his feet in a boundless panorama, that the Primrose tribe acquires its greatest beauty. Living unharmed beneath a bed of snow during the 190 LETTER XV. cold weather, where it is protected alike from light and from drying winds, as soon as the snow is melted it springs forth bedecked with the gayest tints imagi- nable ; yellow, and white, and purple, violet, lilac, and sky blue are the usual colours of its flowers ; while its leaves, nursed by the food descending from a thousand rills of the purest waters, and expanded beneath an ever genial and cloudless sky, acquire a green which no gem can excel in depth or bright- ness. It is in those regions only that the Primrose tribe can be studied to the greatest advantage. EXPLANATION OF PLATE XV. I. Toe Borace Trise.—A portion of the inflorescence of Violet Alkanet (Anchusa italica), shewing its gyrate disposition.—l. A co- rolla opened, exhibiting the stamens and the scales which close its throat.—2. A calyx.—3. The four-lobed ovary, style and stigma.— 4, The calyx of the fruit.—5. The four-lobed fruit with the withered style still remaining.—6. One of the seed-like lobes of the fruit divided perpendicularly; a, the part which separated from the recep- tacle; 64, the organic apex; c, the organic base: these are inverted in the drawing so that the section may correspond with the position of the lobes in fig. 5. Il. Tue NiegutsHape Tripe.—A twig of Black Nightshade (Solanum nigrum).—1. A corolla laid open; a, the holes through which the pollen is discharged by the anthers.—2*. The pistil and calyx.—2**, A horizontal section of the ovary, exhibiting the nume- rous seeds lying in the two cells.—3. A cluster of ripe fruit.—4. A seed.—5. The same divided perpendicularly, shewing the manner in which the embryo is coiled up. “LIBRARY OF THE UNIVERSITY OF ILLINOIS ¢ y Mant. TOSS, ¢ hoe y Hotehot nil. La — ‘ Lupe le ; oxy Lowe : LETTER XVI. THE MINT TRIBE—THE FOXGLOVE TRIBE. eaaae (Plate XVI.) One of the easiest of all natural orders to recog- nise is the Borage tribe, which formed the subject of part of my last letter. Its coiled or gyrate inflo- rescence and four-lobed ovary are so peculiar, as never to escape the observation of the most careless in- quirer. ‘There is only one way in which a mistake may be made by a beginner, and that I shall now teach you how to avoid. Of all the weeds of common occurrence, that which is perhaps the most universally distributed, and which appears by the strength of its constitution the best adapted to flourish in situations where little else can erow, 1s Black Horehound (Ballota nigra). Even by the sides of the high road, in the midst of the hot- test and dryest weather, when it becomes literally cased in a thick coating of dust, that plant flowers, regardless of the elements and their effects. You may know it by its dull dusty disagreeable smell, its roundish indented wrinkled dull grey leaves, placed opposite each other on a square stem, and its whorled clusters of dull purple flowers. ‘The ovary is split 192 LETTER XVI: into four lobes ; its fruit consists of four black grains, which are the divisions of the ovary in a hardened state, and in fact it is so very like the fruit of a plant of the Borage tribe, that I am quite sure when you look at its monopetalous corolla, you will believe that it belongs to that natural order. But pursue your examination of it a little further, and see whether its other characters are also im ac- cordance with those of the Borage tribe. Its leaves for example—are they covered with stiff hairs? no— are they placed alternately on the stem? no—have they the insipid taste, &c. of the Borages ? no—are the flowers arranged in a coiled or gyrate inflores- cence ? is the corolla regular ? are there five stamens ? to all these questions the answer still is no, no, no. The Black Horehound does not belong to the Bo- rage tribe. Look then rather more exactly into the structure of the flowers ; for there can now be no doubt that it is a part of some natural order you have not yet ex- amined. Its calyx (Plate XVI. 1. fig. 1.) is a tube with five sharp-pointed teeth (a.), and is consequently formed of five sepals. ‘The corolla is hairy and tubu- lar at the base (fig. 1.), and divided at the top into two unequal parts called lips ; of these lips the upper is narrow and concave (0.), the lower is flat, and di- vided into three lobes (c.), of which that in the middle is much larger than the two side ones ; this corolla is therefore very irregular. ‘To see the stamens dis- tinctly, the best plan is to slit open the corolla (fig. 2.); you will then find that there are four of them, THE MINT TRIBE. 193 two being shorter than the others; their anthers consist of two lobes which diverge very much, and are only connected just at the tips (fig. 3.). The structure of the ovary and fruit (figs. 4. & 6.) is like that of the Borage tribe ; but the style is uniformly forked at its upper end, and has a very minute stigma on each point of the fork (fig. 5.). Plants thus constructed, and there is a considerable number of them, form what Botanists term Labiate, and which may be called in English the Mint tribe. They are known from all, except the Borages, by their four-lobed ovary; and from the Borages they are distinguished by their opposite leaves, square stems, irregular flowers, and several other characters ; espe- cially by a total difference in their sensible proper- ties. While all the Borages are insipid and _ scent- less, the Mint tribe consists of aromatic herbs, whose leaves and flowers are both impregnated with a vola- tile matter which is continually exhaling, and which becomes exceedingly perceptible when the parts are rubbed. For instance, Lavender, Thyme, and fose- mary, Mint, Basil, Sage, Marjoram, and Clary, the common aromatic herbs of the Kitchen Garden, are all relatives of each other, and belong to this natural order. Of our wild flowers the most remarkable genera, besides those above mentioned, are the Dead Nettles (Lamium), with their strong-smelling leaves and flow- ers of purple or white; Bugles (Ajuga), with blue flowers and creeping stems ; Ground Ivy (Glechoma), that crawls over the bottoms of dry ditches and up 0 194 LETTER XVI. the sides of banks among the grass; Woundwort (Stachys), which owes its name to the blood-red stains upon its corolla; Self-heal (Prunella), peeping up among the sward of commons and old pastures ; and Gipsy-wort (Lycopus), with its minute pale rosy flowers, which inhabits the banks of rivers and lakes, and yields a deep brown stain when its leaves are bruised in water. All these and a thousand more agree in having perfectly harmless properties, and are for the most part aromatic; their favourite places of resort are hedges, woods, and shady lanes; they spring up on the sloping face of chalky downs, and enamel the meadows of subalpine regions; even the scorching sun of Syrian deserts they can endure, but they are unable to support the most intense cold in which vegetation can exist. In Melville Island, for instance, situated in the Arctic Ocean, none of the tribe were found by Captain Parry’s officers, although Saxifra- ges, little Potentillas, and many other pretty flowers appear in the summer through the thin coating of soil which conceals the everlasting ice of that deso- late region. Far removed from these in their qualities, for many are poisonous, and all suspicious, although ex- tremely similar in most points of organization, are the beautiful plants which form the Foxglove tribe (Plate XVI. 2.). They are known by their fruit not consisting of four seed-like lobes, but being a hollow case, or capsule (fig. 7.), contaiming two cells (fig. 9,), and a great number of seeds. In the irregu- THE FOXGLOVE TRIBE. 195 larity of the corolla and stamens, they exactly agree with the last, only it is carried much farther in the Foxglove tribe than in the Mint tribe: for the pe- tals are sometimes so irregularly combined, that one can scarcely make out their real number and nature by any of the ordinary tests; as in the charming genus Calccolaria, the lower lip of whose corolla is inflated like the foot of a clumsy slipper, and in the still more remarkable Chilian Schizanthus, whose corolla is cut and slashed as if it had been clipped with a pair of shears. No better example of this order can be selected than the common Foxglove (Digitalis), which is so striking an ornament of many parts of England. Its corolla (fig. 1.) is a large inflated body, with its throat spotted with rich purple, and it border divided ob- liquely into five very short lobes, of which the two upper are the smaller; its four stamens are of un- equal length (fig. 2.); and its style is divided into two lobes (fig. 6.) at the upper end. A number of long glandular hairs cover the ovary (fig. 5.), which contains two cells, and a great quantity of ovules. This will show you what the usual character is of the Foxglove tribe; and you will find that all the other genera referred to it in books agree with it essentially, although they differ in subordinate points. It is chiefly in the form of the corolla, in the number of the stamens, in the consistence of the rind of the fruit, its form, and the number of seeds it contains, and in the manner in which the sepals are combined, that these differences consist. 02 196 LETTER XVI. Thus Figwort (Scrophularia) has a globular corolla, with a large upper, and a very small lower lip; Speedwell (Veronica), with its spikes of blue, has only two stamens; Snapdragon(Antirrhinum) has the throat of the lower lip so prominent as to press against the upper ; Monkey flowers (Mimulus) have the angles of the calyx winged ; and the woolly AZulleins (Verbas- cum), a corolla with scarcely any tube. No genus is more remarkable than Pentstemon, of which so many fine American species adorn our gardens; in that plant there are actually five stamens, four of which are of two different lengths, as is usual, while the fifth is long and slender, very hairy at the point, and projects into the very mouth of the corolla; it is, however, notwithstanding its size, imperfect: for it bears no anther. This plant is interesting, as shew- ing that in such irregular flowers as those of the Mint and Foxglove tribes, there is a tendency to become regular, which is sometimes very strongly manifested. To render a Foxglove regular, it should not only have the divisions of its calyx and corolla of the same size, and of the same number; but the stamens should agree in number with those; that is to say, as there are five sepals and five lobes to the co- rolla, there should also be five stamens, instead of four, to constitute perfect regularity. It is con- sidered that in those plants in which there are only four stamens, the fifth is abortive or undeveloped, and that when two stamens only appear, the three others are abortive. This will explain to you why a fifth stamen appears in Pentstemon ; and also the THE FOXGLOVE TRIBE. 197 nature of a little scale which is very often found at the back of the corolla in these two-lipped corollas ; the scale is a stamen in a rudimentary state. If you next compare the structure of the Foxglove tribe with that of the Nightshade, you will remark that the resemblance between them is quite as great as between the Foxglove and the Mint tribe; only ina different way. ‘They both have monopetalous flowers, five divisions of the calyx and corolla, and an ovary with two cells; but in the Nightshade tribe the stamens uniformly correspond in number with the lobes of the calyx and corolla ; while in the Foxglove tribe they are uniformly fewer; in a word, the flowers of the former are symmetrical and regular, of the latter, unsymmetrical and irregular, and this is the ereat distinction between them. With this I must abandon the explanation of the Monopetalous Dicotyledonous natural orders, which have more than one carpel in each flower; my next letter will be confined to those, the carpel of which is absolutely solitary and simple. EXPLANATION OF PLATE XVI. I. Tae Mint Trise.—l. A flower of Black Horehound (Ballota nigra) ; a, a lobe of the calyx; 6, the upper lip of the corolla; ¢, the lower lip.—2. A corolla split open to shew the position of the sta- mens.—3. The top of a filament, with its anther.—4. A pistil; a, a fleshy disk, out of which springs the four-lobed ovary.—5. The two lobes of the style.—6. A ripe fruit before the lobes separate.~— 7. One of the lobes apart.—8. A fruit cut through horizontally, shewing the four embryos at a. 198 If. Tae Foxciove Trise.—l. A flower of Purple Foxglove (Digitalis purpurea).—2. The stamens projecting from the base of the corolla.—3. An anther.—4. The pistil, after the corolla has dropped off.—5. The same without its calyx.—6. The top of the style and the stigma.—7. A ripe fruit, burst into two valves, and leaving the receptacles of the seeds in the middle.—8. A perpendicular see- tion of the same, with the receptacles left.—9. A horizontal section of a half-grown fruit, shewing the precise shape of the receptacles of the seeds.—10. A seed.—11. A perpendicular, and 12, a hori- zontal section of the same, exhibiting the embryo lying in the midst of albumen. (N. B. These details are after a drawing by Mr. Francis Bauer). LIBRARY OF THE PIRI (CAOIiry OF 37 z TRIARO ¥ WLP PELL sg et dares as at LL. N “\ \) * A Ma tea z . SALVO ZO Ls lowe? / 7 Lem tO nlf LETTER XVII. COMPOSITE FLOWERS—THE RIBGRASS TRIBE. rere nares cone crane rence eeoronrorercmrece rece (Plate XVII.) Berore I come to my promised analysis of the orders of Monopetalous plants I must beg you to give your attention to two more tribes, in which there are many singular points of structure, and which in particular differs from all that have gone before in having only one carpel in each flower; a simple and obvious difference, which you will be sure to remember. “Take,” says Rousseau, whom I shall here follow very closely, ‘‘ Take one of those little flowers which cover all the pastures, and which every body knows by the name of Daisy. Look at it well; for I am sure you would have never guessed from its appear- ance, that this flower, which is so small and delicate, is really composed of between two and three hundred other flowers, all of them perfect, that is, each of them having its corolla, stamens, pistil, and fruit ; in a word, as perfect in its species as a flower of the Hyacinth or Lily. Every one of those leaves, which are white above and red underneath, and form a kind of crown round the flower, appearing to 200 LETTER XVII. be nothing more than little petals, are in reality so many true flowers; and every one of those tiny yellow things also, which you see in the centre, and which at first you have perhaps taken for nothing but stamens, are real flowers. If your fingers were already exercised in botanical dissections, and you were armed with a good glass, and plenty of patience, I might convince you of the truth of this; but at present you must begin, if you please, by believing me on my word, for fear of fatiguing your attention upon atoms. However, to put you at least in the way, pull out one of the white leaves from the flower ; you will think at first that it is flat from one end to the other; but look carefully at the end by which it was fastened to the flower, and you will see that this end is not flat, but round and hollow, in form of a tube, and that a_ little thread ending in two horns, issues from the tube; this thread is the forked style of the flower, which, as you now see, is flat only at top. “ Next, look at those little yellow things in the middle of the flower, and which, as I have told you, are all so many flowers; if the flower is sufficiently advanced, you will see some of them open in the middle, and even cut into several parts. ‘These are monopetalous corollas, which expand, and a glass will easily discover in them the pistil, and even the anthers with which it is surrounded. Commonly the yellow florets towards the centre are still rounded and closed. ‘These, however, are flowers like the others, but not yet open; for they expand suc- cessively from the edge inwards. ‘This is enough COMPOSITE FLOWERS. 201 to shew you by the eye, the possibility that all these small affairs, both white and yellow, may be so many distinct flowers; and this is a constant fact. You perceive, nevertheless, that all these little flowers are pressed, and inclosed in a calyx, which is common to them all, and which is that of the Daisy. In consider- ing then the whole Daisy as one flower, we give it a very significant name, when we call it a composite flower. Now, there are many genera and species of flowers formed, like the Daisy, of an assemblage of other smaller flowers, contained in a common calyx. This is what constitutes the sixth tribe, of which I pro- posed to treat, namely, that of the Composite Flowers.” Thus, in his admirable gossiping manner does Rous- seau set about explaining the structure of a composITE or compound flower; I shall not continue to follow him, but take my own way of illustrating the subject fur- ther ; stopping, in the first place, to notice two inac- curacies into which he has fallen, in common with all writers of the same day. The cluster of little flowers or florets, which he calls the flower of the Daisy, although qualified by the addition of com- posite, leads unnecessarily to a confusion of ideas, and is much better designated by the term flower- head (or head of flowers), which it really is; the other error is that of calling the little leaves that surround the florets a calyx ; he should have said they were an involucre. The word calyx strictly belongs to a single flower, and not to a collection of flowers ; while involucre is precisely the term that expresses an assemblage of little leaves or bracts 202 LETTER XVII. round a number of flowers. You have already had an excellent instance of it in Umbelliferous plants, and this is another. Rousseau took the Daisy to explain the structure of Composite flowers, because it is so very common a plant; but it has the defect, as a means of illustration, that its parts are so very small, as to be distinguished with difficulty, and that it does not comprehend so many points of structure as some others. For these reasons, I will recommend you to take a plant equally common in gardens in the autumn, the french Ma- rigold (Tagetes patula, Plate XVII. 1.), an old- fashioned, but pretty flower, which is not lable to the same objections. Its flower-head (fig. 1.) is surrounded externally by an olive green cup, formed of several bracts which have grown together at the edge (fig. 6.); this cup is the involucre. Next the involucre are placed several florets (figs. 1. & 2.), whose corolla is a broad yellow blade, rounded at the end, and striped with wide streaks of chocolate brown (fig. 2. d.); it is all turned one way, spreading away from the flower- head, and only tubular at the bottom; Rousseau says, such corollas look as if they were gnawed off on one side. Technically, they are named ligulate, which signifies strap-shaped, because in the greater part of Composite flowers they are long and narrow ; they are also said to form the ray of the flower-head. At the base of the tube of the corolla you will find a few little narrow hairy scales (fig. 2. 6.), which stand on the top of the ovary, in the place of the calyx. Bo- COMPOSITE FLOWERS. 203 tanists choose to call them the parrus; although in reality they are the calyx, which is only stunted and starved in consequence of its being developed amidst the constant pressure of the florets against each other: the pappus is often altogether absent, as in the Daisy for instance; but it sometimes forms a_ beautiful plume of feathers, which catches the wind and ena- bles the seed to soar into the air, and to scatter itself to a distance. ‘The delicate feathery balls of the Dandelion which children amuse themselves with blowing away into the air, are the fruit of that plant crowned by the pappus. Below the pappus is the ovary (fig. 2. a.), containing one single ovule; it terminates in a slender style, which passes through the tube of the corolla, and forks at the top into two stigmas (fig. 2. e.). In time the ovary becomes a dry hairy fruit (fig. 8.), crowned with the pappus, and con- taining one single seed (fig.9.). Such are the florets of the ray. The middle of the flower-head (fig. 1. b.), included within the ray, is called the pisk; it consists of florets constructed very differently from those of the ray. ‘To examine them conveniently you should pull one of them out (fig. 3.). In the ovary you will find no difference worth naming; the pappus is also like that of the ray, only it is more perfect, and one of its scales is a sort of stiff bristle (fig. 3. b.). The corolla is of quite another kind ; it is tubular from the bottom to the top; towards the top it widens, and at last separates into five little divisions which are covered all over with hairs in the inside; this 204: LETTER XVII. kind of floret is called tubular. The stigmas are two ( fig. 7.), and project beyond the mouth of a little hollow cylinder, which is found at the orifice of all the tubular florets of the disk (fig. 4. a.). At first sight you may be at a loss to determine what the cylinder is: but if you use a magnifying glass, you will presently discover that it is formed of five anthers, which grow together by their edges, im the same manner as petals grow by theirs, when they form a monopetalous corolla. It is easy to slit this cylin- der (fig. 5.), and then you will see that each anther has its filament, and two lobes containing the pollen. The broad flat part, out of which the florets grow (fig. 6. a.), is called the RECEPTACLE; it is some- times covered with scales, or hairs, or is even pitted with hexagonal depressions, which look like the cells of honeycomb. Can you guess to what, in other plants, this receptacle is analogous? for you may be sure it is only some very common part masqued and disguised, to the eyes of an ordinary observer. ‘To understand it, you should first compare the flower- head of a composite flower, with an umbel (See Letter II.). In the latter the flowers are all on long stalks, that proceed from a common point, which is the termination of the stem or branch; their point of origin is wider than the stem itself, because of the number of stalks, for whose bases room has to be found; the stalks, however, are very slender, and do not occupy much room. But suppose the flowers of an umbel had no stalks, but were seated close upon the stem, as sometimes happens ; it is obvious that as COMPOSITE FLOWERS. 205 they are much stouter than their stalks, the stem would, in such a case, have to be expanded much more in order to receive them; in fact it would become a receptacle such as you find in a Daisy. The receptacle of a composite flower is therefore an expanded part of a stem. You may also look at its structure in another way. Take a spike of Ribgrass, an exceedingly common weed, about which I shall say something at the end of this letter ; place it by the side of a flower-head of French Marigold; let the letter e in both cases re- present the base of the inflorescence, and b the top of the spike of Ribgrass (Plate XVII. 2. fig. 1.), and the centre of the disk of the French Marigold (Plate XVII. 1. fig. 1.). Suppose the spike of Rib- grass to be very much shortened, the number of flowers upon it remaining the same; the distance from b to e will be proportionably diminished, and the flowers will be much more crowded. Let this shorten- ing be carried still further, the number of flowers still remaining the same, and it is obvious that in order to make room for the flowers, side by side, the stem must expand horizontally; a receptacle will then be produced, and a little reflection will shew you that the letter 6 will then indicate precisely the same parts in both plants: the centre of the French Mari- gold being the same as the point of the spike of Rib- grass. The receptacle of a compound flower is there- fore both a contracted and expanded stem. With regard to the involucre, Rousseau has well ob- served, that it has generally the property of opening 206 LETTER XVII. when the florets expand, of closing when the corollas fall off, im order to confine the young fruit; and lastly, of opening again and turning quite back to give more room to the fruit, which increases in size as it grows ripe. ‘This is particularly remarkable in the Dandelion. Let us now pass from these considerations to a view of the sections into which Composite Flowers are naturally divided. If you gather a head of Dandelion (Leontodon Taraxacum), you will find that both the ray and the disk are composed of ligulate florets, to the total ex- clusion of tubular ones. Such plants are called Sue- cory-headed (Cichoracee), and are remarkable for their stems yielding a white milk, which, when con- centrated, has a soporific quality. The other sections are destitute of this property. Here are arranged num- bers of our wild flowers, such as Goat’s beard (‘Trago- pogon), Sow Thistle (Sonchus oleraceus), Wall Lettuce (Prenanthes), Hawkweed (Hieracium), and the shabby Succory (Cichorium Intybus), with its ragged leaves, and pale blue florets. It is also to this section that the Lettuce and Endive of the garden belong. From the last you will easily distinguish what is called the Thistle-headed section (Cinaracez). These plants have no ligulate florets; all the florets are tubular, generally very wide at the mouth, and so much spreading beyond the involucre as to give the flower-head almost an hemispherical form. The leaves of the involucre are also, in most of the species, hard and spiny. It is in this section that you will COMPOSITE FLOWERS. 207 find all the Thistles, Saw-worts (Serratula), and Blue Bottles (Centaurea); it is also remarkable for con- taining the Artichoke (Cynara Scolymus), the bottom of which you have probably often eaten without thinking much about Botany. The next time you have one on the table, remember that the scales, which you suck are the imvolucre, the bottom is the receptacle, and the choke, which is thrown away, is a collection of florets, separated from each other by numerous stiff hairs, growing out of the receptacle. The third section has heads composed of both sorts of florets; tubular ones in the disk, and ligulate ones in the ray; hence they are called Radiate (Corym- biferee). It sometimes happens that these have no ray, and then the young student might naturally confound them with the Thistle-headed section ; but this need not be done if you remark that the florets of the Thistle- headed section are very wide in the mouth, and spread over the sides of the involucre, the scales of which are usually hard and spiny, while the florets of the Radiate section are narrow in the mouth, and not longer than the scales of the imvolucre, which are usually soft and leafy. A very little practice will soon prevent your falling into any such error. By far the greater part of Composite flowers belong to the Radiate section ; Sunflowers, Asters, Daisies (Bellis), Chrysanthemums, Marigolds, Wormwood (Artemisia), Cudweed (Gnapha- lium), Coltsfoot (Tussilago), Groundsel (Senecio) and Chamomile (Anthemis), with thousands of others, for this section is of prodigious extent, form a most strik- ing feature in the vegetable kingdom. 208 LETTER XVII. When we were talking of Umbelliferous plants I cautioned you against committing the error of sup- posing that all plants with their flowers in umbels belonged to that natural order. In like manner I must now explain to you that although the arrange- ment of florets in heads is universal in Composite flowers, yet that there are many plants in the world whose florets are placed in the same manner, but which do not belong to this tribe. For instance, Eryngo, which is an Umbelliferous plant, has its flowers in heads, so has Sanicle, another genus of the same order; and Yeasel (Dipsacus) and Scabious (Scabiosa) are so extremely like Composite flowers in appearance, that you would never suspect them of being strangers of another family, if you were not apprized that no plants belong to the tribe of Com- posite flowers, which have not their anthers united into a cylinder. ‘This it is which, taken with the dis- position of the florets in heads, alone gives a positive character to the plants I have been speaking of. This remembered, you are mistress of the key to six or seven thousand species. A few words upon the plant called Ribgrass, to which I have already alluded, and I pass at once to my promis- ed analysis of the Monopetalous Dicotyledonous orders. Ribgrass (Plantago) is a weed common at the foot of walls, by the side of pathways, and in moist places generally. It derives its name from its leaves having remarkably strong ribs passing from the bottom to the top: it has no apparent stem, but the leaves lie flat on the ground. The flowers (Plate X VII. 2. fig. 1.) THE RIBGRASS TRIBE. 209 are white and green, disposed very closely in a long spike, and remarkable for their long stamens, the filaments of which soon become too weak to support the heavy anthers. Each flower has a hol- low bract on its outside (fig. 2. b.), and a calyx of four green sepals, which are also concave, and overlie each other very much at the edges. The corolla is a thin, almost transparent, greenish-white body, divided at the end into four lobes (fig. 2. c.) which fall back on the sepals. our stamens arise from the tube of the corolla, bearing on their filaments inverted arrow-shaped anthers. ‘The ovary (fig. 6.) contains two cells, in each of which are many seeds (figs. 7, 8.), but it terminates in a simple hairy stigma; on this account it is considered to be formed of a simple carpel, notwithstanding its two cells. In the course of time, the receptacle of the ovules separates from the sides of the ovary, and becomes covered all over with seeds of a pale chesnut colour (fig. 10.); at the same time the style drops off the ovary, which changes to a little hard dry brown case or capsule (fig. 9.), sur- rounded with the sepals, and separating transversely into two parts, by giving way at its base. These characters entitle the Ribgrass to be con- sidered the representative of a very distinct, although very small natural order, called the Ribgrass tribe ; which is, however, of too little importance to make it worth detaining you longer about it. Now let us again consider the most essential distinc- tions of the Monopetalous orders, I have recommended P 210 LETTER XVII. to your study. Although they form only a part of what really exist, yet a clear knowledge of them is a great step towards that of the remainder. I think the dis- tinction will be sufficiently well expressed in a tabu- lar form, without any preliminary explanation, beyond this, that the number of the carpels, out of which the ovary is formed, is the most important fundamental distinction to employ. * Ovary formed of more carpels than two. Flowers regular—The Borage tribe.+ Flowers wregular—The Mint tribe. Erect bushes—The Heath tribe. Climbing plants—The Bindweed tribe. Ovary split into four lobes } Ovary not split into lobes ; ** Ovary formed of two carpels. Milky Anthers all separate—The Harebell tribe. Ovary plants Anthers all united —The Lobelia tribe. inferior ) Not Milky sates tl UE stipules—The Honeysuckle tribe plants Leaves with stipules—The Coffee tribe. ” Flowers irregular : : The Foxglove tribe. Ovary Stamens two : : The Olive tribe. Superior ) Flowers : riamiies Leaves opposite § The Gentian gular ; i = ( ( ribbed tribe. Stamens five 3 " Leaves The Night- alternate shade tribe. #%* Ovary formed of only one carpel. Anthers united inacylinder_ . ; Composite Flowers. Anthers distinct : ‘ The Ribgrass tribe. + I hope the learned reader will pardon my having placed these two orders among those whose ovary is formed of more carpels than two. My reason for doing so is that they seem as if so constructed, and it would be difficult to make a beginner understand that they are not. Cae EXPLANATION OF PLATE XVII. I. Composite FLrowers.—1. Halfa flower-head of French Mari- gold (Tagetes patula); a florets of the ray ; 4 florets of the disk ; ¢ section of involucre; d receptacle; e flower-stalk.—2. A floret of the ray; @ ovary; b pappus ; ¢ tube, and d bladeof the corolla.—3. Floret of the disk ; @ ovary; 4 pappus; ¢ corolla.—4. Cylinder of stamens. —5. The same slit open and unrolled.—6. Half an involuere ; a the receptacle.—7. The two stigmas.—8. A grain, ripe and crowned by the pappus 4.—9. A section of a seed, shewing the embryo. II. Toe Riscrass Tripe.—1. A spike of flowers of Broad-leaved Ribgrass (Plantago major).—2. A separate flower; athe calyx; 6a bract; ¢ the corolla.—3. A section of the calyx to shew the relative position of the sepals to each other; 6 the bract.—4. A sepal.—s. An anther with a part of a filament.—6. A pistil—7. An ovary cut perpendicularly.—8. The same divided horizontally.—9. A ripe fruit invested by its calyx.—10. A cluster of seeds upon the receptacle, as they are left when the shell of the fruit falls off—11. A seed.—12, The same cut through to shew the embryo. PQ LETTER XVIII. DISTINCTIONS OF EXOGENOUS OR DICOTYLEDONOUS, AND OF ENDOGENOUS OR MONOCOTYLEDONOUS PLANTS—THE NARCISSUS TRIBE—-THE CORNFLAG TRIBE. (Plate XVIII.) In my last letter I took leave of Dicotyledonous plants, whieh I am persuaded you are by this time able to recognize by their general aspect, as well as by the technical distinctions to which I have chiefly called your attention. It is not their netted leaves, nor the concentric circles in their stems when woody, nor the two-seeded lobes of the embryo alone, by which they are known, but also other characters in combination with those. Their leaves are usually jointed with the stem, so that they are thrown off at certain seasons: in deciduous trees in the autumn, in evergreens in the spring or summer ; their flowers, if perfect, or nearly so, are mostly divided by four or five; that is, have four or five sepals, and four or five petals, either distinct or combined ; and finally, their mode of growth is, in general, by branching re- peatedly to form round-headed trees, or broad spreading bushy herbs. All these circumstances are characteristic of Dicotyledonous plants ; but most of them are occasionally subject to exceptions. When exceptions occur in regard to any one circumstance, NVI/T. 7. . PA: . lia boop 4 ¢ 7 - Wy, VY a Spa tia. LIBRARY "OF THE “UNIVERSITY OF iLLiNGts DISTINCTIONS OF CLASSES. 913 attention should then be paid to others, for the pur- pose of ascertaining, whether, although a plant may appear in some one point of structure not to be Dicotyledonous, it may not upon the whole possess the characters of that great division. For instance, the common garden Pink, has leaves which are not netted; you might suppose on that account that it is not Dicotyledonous; but when you find that it is a branching plant, with five divisions of the calyx, five petals, and ten stamens, you may be sure that it is Dicotyledonous, notwithstanding the ap- parent deviation of the leaves from the general rule of structure. All this will be more clear to you, when you be- come acquainted practically with monocoryLEDONOUS plants; which are quite different things. They often shoot up into the air without any branches, and con- sequently have a sharp-headed appearance when they form trees; there is only one seed-lobe to their embryo; and their stem has no trace, whatever, of concentric circles ; on the contrary, it presents, when cut across, one uniform dotted surface, as you may see if you take a piece of the common cane, which is split for the bottoms of chairs, and which is in reality the stem of a sort of Palm. Instead of enlarging their stems by the addition of new wood to the out- side of the old, Monocotyledonous plants only add new matter to the centre of that which previously existed, on which account they are named ENDo- GENOoUS (or growers inwardly). The veins of their leaves run in nearly parallel lines from the base to 214 LETTER XVIII. the point of the blade, without branching, or forming a kind of net work, as in the leaves of grasses or lilies; so that in this respect they are immediately known from Dicotyledonous plants. ‘Their flowers, moreover, are almost always divided by three, instead of by four or five ; you will, for instance, generally find three sepals, and three petals, and three, or twice three stamens, and an ovary made up of three car- pels; so that there are abundant means of dis- tinguishing Monocotyledonous plants, whether you have only their stem, or their leaves, or their flowers, or even their fruit to examine. Now just observe, how important this is; suppose you saw a simple-veined leaf of some plant, and nothing further ; although you might not be able to tell the name of the plant which bore the leaf, nor even its natural order, yet you would know that its stem must have grown by addition to its inside, that its embryo had only one seed-lobe, and that its flowers would in all probability be divided into three sepals, and three petals. Nor is this all; nearly the whole of Monoco- tyledonous plants are harmless; the chances would therefore be, that your leaf belonged to some harm- less plant; and if it were the leaf of a tree, you would be perfectly certain that it came from some hot climate ; for no Monocotyledonous trees are found in cold couutries. The inspection of a mere leaf would therefore lead you to a number of useful and interesting conclusions, at which you could never arrive if you studied Botany according to an artificial system. DISTINCTION OF CLASSES. 215 As much of the facility of distinguishing Mono- cotyledonous from Dicotyledonous plants depends upon a familiarity with the appearance of their leaves, let me recommend you, before we proceed any further to procure those of Corn or Grass, of the Pine Apple, the Hyacinth, the Tulip, or the Daffodil, and compare them with any of the Dicotyledonous plants, you are now familiar with. In the mean- while I will sketch a comparative view of Monocoty- ledonous and Dicotyledonous plants, which you can afterwards study at your leisure. DICOTYLEDONOUS PLANTS. MONGCOTYLEDONOUS PLANTS. Stems generally branched, & when | Stems generally quite simple; and old covered with cracked bark. when old covered with smooth | bark. Wood, consisting of concentric Wood, not consisting of concentric circles; the central part the circles; the central part the oldest and hardest; the bark youngest and softest; the bark connected with a central pith,,; not connected with a central pith by means of medullary by means of thin plates called medullary rays. rays. Leaves, with veins arranged in a | Leaves, with simple parallel veins, netted manner; usually jointed which are not netted; usually with the stem. not jointed with the stem. Flowers, usually with the parts ar- | Flowers, usually with the parts ar- ranged in fours or fives. | ranged in threes. Embryo, with two or more seed- | Embryo, with only one seed-lobe, lobes, or cotyledons. | or cotyledon. Found wild as trees all over the | Found wild as trees only in hot world, except in thevery highest _—_ climates, and chiefly within the latitudes. | tropics. | These preliminary observations will, I trust, have conveyed to you some general notions of the nature 216 LETTER XVIII. of Monocotyledonous plants: among which you will find that many of the commonest and most useful tribes are arranged. You will scarcely, however, have suspected that Lilies, and Palms, and Bananas, with Hyacinths, Squills, Daffodils, and Orchises, were associated with Grasses, Rushes, and Sedges; the natural affinity of all these is what we have now to study. In order to entice my young friends onwards, and to prevent their getting weary of their pursuit at a time when I am most anxious that their attention should be fixed, I shall begin with a natural order, the species of which are so generally admired, that I am sure they will wish to understand it botanically. The Daffodil, called by Botanists Narcissus, repre- sents a group of plants, having fine gay flowers, and long narrow strap-shaped leaves arise from bulbs which grow under ground. It is called in Eng- lish the Narcissus tribe. We will not, however, take the Daffodil to illustrate it, for reasons that I shall mention by and bye. A_ beautiful Chilan plant, called the sharp-leaved Alstromeria, of which I send you a drawing (Plate XVIII. 1.), and which is now not very uncommon in gardens, will shew you the general structure of this tribe in a more satisfactory manner. Its leaves are of a firm and rather fleshy texture, gradually tapering to the point, and are filled with sim- ple veins. It has an inferior ovary (fig. 1. a.) with three angles, three cells, and many seeds in each cell. From the upper end of the ovary rises a richly coloured reddish-orange calyx of three sepals, mside THE NARCISSUS TRIBE. 217 which are three orange-coloured petals, shaped ex- actly like the sepals; these are all rolled together so as to form a kind of bell. ‘The stamens ( fig. 2. a.) are six, and are remarkable for bearing blueish- purple anthers; a very uncommon colour for those parts. From the top of the ovary springs a three- cornered style, terminated by a three-lobed stigma (fig. 3.). Finally, a dull greenish-brown capsule is ripened, which is marked externally by six ribs (fig. 4.), and a horizontal line, which indicates the place whence the calyx, corolla, and stamens fell; when perfectly ripe it separates into three concave valves (fig. 5.), each of which carries away with itself a portion of the receptacle (a.) of the seeds. The seeds are spherical (fig. 6.), and consist of a great mass of albumen, in which les a little cylindrical embryo (fig. 7.). This form of embryo is the most common in Monocotyledonous plants. Its upper end is the cotyledon, its lower the radicle, and the plumule or rudiment of a stem les concealed in the former. Of these characters a part is confined to the genus Alstromeria, and a part peculiar to the Narcissus tribe. The latter is briefly this: an inferwr ovary, calyx and corolla of the same form, and six stamens (or more). To this definition answers the Daffodil im all respects ; but it has, in addition, a long cup, which is a row of abortive stamens; and this circumstance marks its genus. Some very fragrant hot-house plants, called Pancratiums, or Sea-side Lilies, also have a 218 LETTER XVIII. cup, but their anthers arise from its border, which at once distinguishes them from the Daffodil. It is to this order that also belong the golden Sternberqna of autumn, the scarlet Amaryllises of Bra- zil, the Belladonna Lilies of the Cape, and Crinums, with their long and relaxed petals, sometimes of the French white, and sometimes deeply stained with crimson. Snow-drops, too (Galanthus), and Snow- flakes (Leucojum), whose names so well express their colour, the ruby-petaled Werines, to which belongs the Guernsey Lily ; and Blood-flowers (Hemanthus), whose juice is a mortal poison, are all allies of the Narcissus. We have often seen that venomous properties lurk beneath the fairest forms, and that external appear- ance offers no beacon to warn tue traveller of the plants in which danger lies concealed. The Nar- cissus tribe affords another instance; the bulbs of the Daffodil are emetic, those of the Blood-flower yield a deadly gluey poison, with which the African savages smear their arrow-heads, and the bulbs of the whole tribe are suspicious. Fortunately, however, its bota- nical characters are so precise, that there is no diffi- culty in distinguishing it from all others. So like is a Crocus to some of the Narcissus tribe, that a student would naturally suppose it to belong to it, especially when he found that it also had an in- ferior ovary, with three cells, and its sepals and petals so much alike, as to be distinguishable only by one being rather differently coloured, and placed on the outside of the other. It differs, however, in having 4 THE CORNFLAG TRIBE. 219 only three stamens instead of six, and in the anthers being turned with their faces towards the sepals, in- stead of towards the style; a singular peculiarity, which in this case is found to indicate a total absence of poisonous properties ; so that while the Narcissus tribe is dangerous, the natural order, called the Cornflag tribe, to which the Crocus belongs, is per- fectly harmless. These plants vary a great deal in their general ap- pearance, owing to the different shapes of the calyx and the corolla, and to the size of the stem, which is sometimes round and subterranean, as in the Crocus, and sometimes long, scarred, and creeping on the surface of the ground, as in the Cornflag or Iris; of which the Orris rout which babies suck is a pre- paration, and the name a corruption. They may, however, be always known by their agreeing with the Narcissus tribe in every thing except their three stamens with the anthers turned away from the style. and the want of bulbs. ‘Their leaves are also very unusually thin, and shaped like a straight sword- blade, with the edge turned to the stem, on which account they used to be called Hnsate, or sword- leaved plants (Plate XVIII. 2. fig. 1.). Along with the drawing of the Alstromeria you have another, which represents a most singular plant, the colour of whose flowers resembles a lizard’s back. {It is a native of the Cape of Good Hope, and called the Wavy Ferraria (Ferraria undulata). Its flowers consists of three sepals and three petals, all of which are so wavy and curly at their edges, and so much 2920 LETTER XVIII. alike that you can hardly distinguish them ; below a kind of cup, formed by the union of these parts, is a long ribbed ovary (fig. 1. a.), which contains three cells and many seeds ( fig. 6.). The three stamens are in this genus grown into a column (fig. 2.) like the column of a Passion-flower; but in other genera they are distinct ; each at its pomt curves away from the stigma as if to convey its anther (fig. 2. d.) as much as possible out of the reach of it, averting from it its face (fiy. 2. d.). The style is a small cylinder, divided at its end into three broad lobes (fig. 2. e.); each of which is separated into two parts (fig. 3.) cut cut up into five hair-like segments: these lobes are the stigmas. In Iris, the genus from which the tribe takes its Latin name (Lridacee), the structure is more curious than in Ferraria; the three sepals are broad and spreading, and often ornamented with a beautiful feathered crest ; the three petals stand erect, and curve over the centre of the flower; while the stigmas are broad richly coloured parts, resembling petals, and curve away from the centre, as in the Ferraria. At first sight you would suppose the Iris was altogether des- titute of stamens; but if you lift up the stigma you will find the runaways snugly hidden beneath their broad lobes, and lying close to a humid lip through which the influence of the pollen is conveyed to the ovules. This widening of the stigma is a very com- mon event in the Cornflag tribe ; even in the Crocus it occurs, only the stigmas are so rolled up that you do not discover it until you unroll them; they are, THE CORNFLAG TRIBE. 2921 in fact, so much heavier than the power of the style can support, that in the Saffron Crocus, in which they constitute the substance called Saffron, they hang down on the outside of the flower like an orange tassel. It is to this natural order that belong those count- less species of Ixia, Gladiolus, Watsonia, Babiana, &c. which spring up at the Cape of Good Hope upon the commencement of the rains, and soon cover the parched and half naked karroos with a robe of the deepest green, adorned with all manner of gay and sparkling colours. Having studied these plants in the order I have mentioned, compare them in your mind with the numerous Dicotyledonous tribes you have already be- come acquainted with, and see whether you can anticipate any difficulty in recognising other tribes of Monocotyledonous plants, by the external characters I have pointed out; without the slightest necessity for having recourse to the examination of their stems or seeds. EXPLANATION OF PLATE XVIII. I. Toe Narcissus Tripe.—1. A shoot of the sharp-leaved Alstro- meria (A. acutifolia); @ the inferior ovary.—2. An ovary deprived of calyx and corolla, but with the stamens in their place.—3. An ovary without even the stamens; shewing the style and stigmas.—4. A ripe fruit of Alstromeria psittacina (the Parrot Alstromeria), just before it separates into valves; @ the scar whence the stamens, calyx, and 222 corolla dropped.—5. One of the valves, with a part of the receptacle of the seeds a adhering to it.—6. A seed.—7. A section of the same; exhibiting the embryo a lying in the midst of the albumen. Il. Tue CornriaG Trise.—1. A piece of the Wavy Ferraria (F. undulata); @ the ovary.—2. A column of stamens; a@ the base of the sepals and petals; 4 the column; e the fore part of the fila- ments; d the anthers; e the stigmas.—3. One of the stigmas sepa- rated from the style-—4. An anther.—5. An ovary; a the place whence the sepals and petals have been removed; 6 the base of the column of stamens.—6. A horizonal section of the ovary. LIERARY OF THE UNIVERSITY OF ILLINOIS < ny / , a 4 , V hts hiphodel S b4Ae 4 ef a Ulta. LETTER XIX. THE ORCHIS TRIBE—THE ASPHODEL TRIBE. (Plate XTX.) Tue last natural order of Monocotyledonous plants, with an inferior ovary, which I propose to mention to you, is the Orchis tribe, one of the most extensive and curious of the Vegetable Kingdom. In the end of May, or beginning of June, you will meet with great numbers of a fine common species in the pastures and meadows, where they rise with their spotted leaves, and spikes of purple or rosy speckled flowers, conspicuous among the herbage that surrounds them. The country people call them Cuckoo-fiowers, because they make their appearance when the cuckoo begins to call. Of these the commonest of all are the Male Orchis(Orchis mascula), and Fool’s Orchis (O. Morio), either of which you may gather for the purpose of examination. Suppose we take Fool’s Orchis. It has a little fleshy root, composed of two oval knobs, and a number of succulent fibres; its leaves spread at the sur- face of the ground, are of a light green, of a narrow strap-shape, tapering to a blunt point, with a soft, rather fleshy texture. and the usual simple-veined structure of Monocotyledonous plants. The stem is 294, LETTER XIX. erect, and about nine inches high, sometimes less, but seldom more; it is covered by two or three leaves wrapped round it, so as to form a sort of sheath; at its top it bears a spike of flowers, coloured with green and white, and having the followmg most remarkable structure. From the bosom of a narrow wavy lance-shaped bract (Plate XIX. 2. fig. 2. f-), springs an angular twisted body, pure green at its lower end, but often stained with red near the top (fig. 2. e.); this is an ovary, containing only one cell, and an inconceivable multitude of minute ovules, arranged in double rows upon three narrow receptacles ; at its point it is grace- fully bent forward, as if to present you with its sin- gular green and pink flower. The first thing that usually strikes an observer, is a broad roundish notched leaf (fig. 1. and 2. a.), hang- ing from out of a sort of casque or helmet, the two sides of which expand and retreat a little (fig. 1. ¢. ¢.), so that they may set off the lively rose colour and rich crimson blotches with their own dull green stripes; this leaf is called the trp (labellum), and separates a little into three divisions, of which the side ones are the most notched and the largest; at its base is a hole (fig. 1. e.) which will prove, upon examination, to be the mouth of a rose-coloured horn, that seems to swing lightly behind the flower (figs. 1. and 2. b.); it is usually called the spur. The other leaves of the flower are thus: two are concave, spreading, a little turned in at the point, and charm- ingly striped with green veins, both within and with- THE ORCHIS TRIBE, 225 out (figs. 1. & 2. c.); another stands quite at the back, coloured with pure rose, and projecting for- ward over the lip (figs. 1. & 2. c*.); below this he two other leaves, narrower, and more delicate than the last, forming, together with it, the casque out of which the lip seems to hang (figs. 1. & 2. d. d.). These are the parts which answer to the calyx and corolla in other plants; at first sight, you will be at a loss how to determine which belongs to the one, and which to the other; and especially to know what the lip is with its spur; look, however, more attentively, and remark, firstly, that the whole number of leaves in the flower is six; and secondly, that three of them, namely, the lip, and two narrower and more delicate leaves, which form part of the casque (figs. 1. & 2. a. & d. d.), are placed within the three others. The first of these (c. c. and c*.) form the calyx, and the last (a. and d. d.) the corolla; a very irregular one, certainly, but nevertheless conformable to all the rules of organization ; as for their irregularity, that is characteristic of the Orchis tribe. A little study and examination by yourself, will satisfy you that, this is the true view of their nature, and all the strange ap- pearance which puzzled you at first, was caused by the unusual manner in which the sepals and petals are shaped and directed, and the disproportionate size of one of them. The next object that is to engage your attention, is far more singular and difficult to understand. In the centre of the flower, in the place of stamens and style, just at the back of the hole that leads down Q 296 LETTER XIX. into the spur, half hidden by the petals, stands a crimson flat body (fig. 3.) having a deep furrow in its front. I should quite despair of explaming the structure of it, without the assistance of a drawing, which I accordingly send you: the parts are a good deal magnified, as is usual in the dissection of flow- ers by Botanists, in order to bring every thing dis- tinctly into view. If you look attentively at the front of the central body (fig. 3. a.), you will remark, in the first place, that it is separated into two lobes, by a deep channel drawn down its middle; and secondly, that each lobe will open, if pressed, by a suture (fig. 3. g.) running through it from one end to the other. Pull asunder the two sides of each lobe, so as to lay open their inside (fig. 4.), and in each there will be seen an olive-green granular mass (fig. 4. g.), tapering gradually into a thin stalk, at the end of which is a viscid semi-transparent gland (fig. 6. a.). If you squeeze a portion of the olive-green granular mass in water, beneath a very powerful microscope, you will be surprised to see that it consists of infinite multi- tudes of grains of pollen stickmg together in threes or fours; it is therefore a mass of pollen in a sin- gular state; and this fact being taken as the basis of your reasoning as to the nature of the other parts connected with it, it will result as a necessary conse- quence, that the central body is an anther, and its sutures the lines of dehiscence, or of opening. At the foot of the anther is a pale whitish-green fleshy cup ( fig. 3. d. and 4. a.), in which the glands at the end of the stalk of the pollen-masses are concealed; this THE ORCHIS TRIBE. 227 which is botanically called the Hoop, or pouch (cucul- lus, or bursicula), is peculiar to some of the Orchis tribe, and is caused by a doubling upwards of the upper edge of the stigma. The stigma itself is a broad viscid shining space ( fig. 3. e.) lying just below the hood, between it and the mouth of the spur. These things being thus made out, it follows, you see, that the column of an Orchis is a body formed of a stamen, a style, and a stigma, all grown into one solid body ; and this is the great peculiarity of the Orchis tribe. Its genera vary amazingly in the structure of the anther, the column, the lip, and in- deed of all the parts, but in the consolidation of the style and stamen. They are all agreed. This then is the characteristic of the Orchis tribe. If, however, there was really only one stamen, this curious natural order would be more at variance with the usual structure of Monocotyledonous plants than its conformity in the calyx and corolla would lead one to expect; and accordingly we find, that al- though only one stamen is perfect, there are distinct traces of two others in an extremely imperfect state. On each side of the anther, near its base, you will find a roundish granular knob (fig. 3. }. c.), which has been ascertained to be the rudiment of another anther; so that in reality the column is composed of one perfect stamen, standing between two imperfect ones ; a most striking proof of the harmony of design which is manifested in all these Monocotyledonous tribes. Qa2 228 LETTER XIX. If you consider the mutual relation which all the parts of the Orchis bear to each other, you will scarcely fail to be struck with one circumstance above all others, namely, the apparent want of any means of com- munication betwen the pollen and the stigma. Not being in fine powder the pollen is not able to be scat- tered in the air, like that of other plants ; if it were to fall out in a mass it would hardly touch the stigma ; and even the possibility of this seems to be purposely prevented by the glutinous gland to which the stalk of the pollen-mass adheres, and which is itself con- fined within the pouch. To account for the manner in which the necessary contact between the stigma and the pollen takes place, two explanations have been given; one that insects, inserting their pro- boscis into the flower in search of honey, disturb and pull out, or unintentionally carry away with them the pollen-mass which sticks to them by means of the gland, and that in the latter case, buzzing from flower to flower they leave it behind them on the stigma of some neighbouring blossom ; the other ex- planation, which has been offered by the celebrated Mr. Bauer, is that the influence of the pollen is not communicated to the stigma, by actual contact of the pollen, as is usual in other cases, but that it passes down the stalk of the pollen-mass, into the gland, and thence to the humid surface of the stigma; and he has shewn that great probability attaches to this opinion, in consequence of the existence in such plants as the Orchis itself, of a beautiful contrivance to secure such a communication. He discovered that in THE ORCHIS TRIBE. 229 the bottom of the pouch, just below the glands, are two little passages (fig. 4. d.), which open directly over exactly that part of the stigma which appears the best adapted for receiving the influence of the pol- len: and that hence the pouch, which seems to the superficial observer a means of preventing communi- cation between the pollen and the stigma, is in fact a most admirable contrivance of nature to ensure it. I leave you to form your opinion, as to which of these two explanations is the more plausible. In this country the more common or remarkable of the wild plants belonging to the Orchis tribe, are the Bee Orchis and Fly Orchs (Ophrys), whose lips re- semble the insects after which they are named; the Man Orchis, and the Lizard Orchis (Aceras), with their yellow or purple strap-like lips ; Neottia, with her russet flowers, and scaly stems, springing from a cluster of entangled roots, which have given her the name of Bird’s Nest; the Butterfly Orchis (Platan- thera) with its long and taper cream-coloured lip ; and the Ladies Slipper (Cypripedium), with its large yellow bladdery flowers, and twin anthers. They all grow on the ground in meadows, or marshes, or wood; and have always been considered the most curious and beautiful plants of a European Flora. But it is in tropical countries, in damp woods, or on the sides of hills in a serene and equal climate, that these glorious flowers are seen in all their beauty. Seated on the branches of living trees, or resting among the decayed bark of fallen trunks, or running over mossy rocks, or hanging above the head of the 230 LETTER XIX. admiring traveller, suspended from the gigantic arm of some monarch of the forest, they develope flowers of the gayest colours, and the most varied forms, and they often fill the woods at night with their mild and delicate fragrance. For a long time such plants were thought incapable of being made to submit to the care of the gardener, and Europeans remained almost ignorant of the most curious tribe in the whole vegetable kingdom. But it has been discovered of late years that by care and perseverance they may be brought to as much perfection in a hot-house as they acquire in their native woods, and they now, under the name Orchidaceous Epiphytes, form the pride of the collections of England. Unfortunately they are of very little known use. Vanilla, which you eat in creams and other sweets, is the pod of a kind which, in the West Indies, creeps over trees and walls like ivy; and a nutritive sub- stance called Salep is prepared from the tubercles of some kinds of Orchis ; a most meagre catalogue of use- ful properties in a tribe of near two thousand species, but one to which little can be added, if we except what is called the Shoemaker plant (Cyrtopodium Andersonii), whose stems afford a glutinous extract employed by the Brazilians for sticking together thin skins of leather, This order, like the two preceding has, as we have seen, an inferior ovary, a character by which they, and several others which I have not time to mention, are readily known. In your study of Monocotyle- donous plants you cannot do better than take this THE ASPHODEL TRIBE. 231 circumstance as a fundamental distinction from which your analysis may be continued. Let us now proceed to some orders in which the ovary is superior. The Hyacinth, Squill, Onion, Star of Bethlehem (Ornithogalum) and Asphodel, belong to a natural order, called the Asphodel tribe, which is remarkable for the extreme simplicity of the structure of all its parts. Three sepals, and three petals of similar form, size, and colour, six stamens, and a superior three- celled ovary, which changes to a fruit containing seeds with a black brittle skin (Plate XIX. 1.), form the essential character, and combine a large number of plants, generally quite harmless, and in the majority of cases remarkable for either their use or their beauty. It is difficult to single out any one species better fitted than another to illustrate the Asphodel tribe, so uniform are they in the more important points of organization. I happen to have at hand the Streaked Onion (Allium striatum), but you may take with equal advantage the common Onion, or any of the others, I have above named, for the purpose of study. The leaves and flowering stems of this plant, rise from a subterranean roundish fleshy body, formed of scales wrapped closely over each other. ‘The scales are of the same nature as those of a bud, namely, the rudiments, or the bases of leaves ; and the body itself, called a BULB, is a kind of underground bud; hence you will perceive that when one talks of Hyacinth roots which are placed in glasses, or of the roots of Onion, Garlic and Shallots, an incorrect kind of 932 LETTER XIX: language is made use of. In one respect, the bulb differs essentially from a bud: it is not a perishable part, intended merely as a protection to the young and tender vital point, from which new growth is to take place: this indeed is a part of its object, but it also serves as a copious reservoir of nutritive matter upon which the young leaves and flowers feed. On this account its scales are not thin and easily withered up, as in a common bud, but succulent, and capable of retaining their moisture during long and severe drought. In this we again see a direct manifestation of the all protecting care of the Deity; for bulbous plants are generally natives of situations which at certain seasons of the year are quite dried up, and where all vegetation would perish if it were not for some such provision as we find in the bulb; in places like the hard dry Karroos of the Cape of Good Hope, where rain falls only for three months in the year, in the parched plains of Barbary, where the ground is rarely refreshed by showers, except in the winter, and on the most burning shores of tropical India, beyond the reach of the tide, and buried in sand, the tempe- rature of which often rises to 180°, bulbous rooted plants are enabled to live, and enliven such scenes with their periodical beauty. You must not, however, imagine, either that all the Asphodel tribe have bulbs, or that all bulbs belong to the Asphodel tribe; of the inaccuracy of the latter notion you must already be aware, if you remember the Narcissus tribe ; the former would be not less a mistake; all that I meant, m thus connect- THE ASPHODEL TRIBE. 233 ing the bulbous structure with the Asphodel tribe, was that it is an exceedingly common characteristic. The Asphodel genus itself has a fleshy fingered root, without any trace of bulb, and some of the genera con- tain trees of considerable size. The leaves are long narrow green straps, and have the simple parallel veins you have been led to expect. The flowering stalk rises directly from the bulb, without any intermediate stem; as it is long, and destitute of leaves, and rather different in appear- ance from a common flower-stalk, it is technically named the scape. At its top it bears an umbel of flowers, at the base of whose long stalks are a number of membranous satiny scales, or bracts ( jig: 1. a.); they are a sort of involucre, but are occa- sionally called a sparne. ‘The three sepals are very evidently placed on the outside of the petals (fig. 2.), but excepting in this respect, they are absolutely the same both in colour, size, form, and direction. Of the six stamens, three are a little smaller than the others; their anthers open by two slits which are turned towards the style. The ovary (fig. 5.) is an oblong body, with three furrows, a single style, and a stigma which exhibits no sign of beimg divided. Inside the ovary you will find three cells, in each of which is a number of ovules (fig. 6.). Last of all comes the fruit; a little brown dry case which splits into three valves (fig. 6*.), to allow of the escape of the angular black seeds, whose skin is of a very brittle nature. This last circumstance of the black 934 LETTER XIX. brittle coating of the seed, is one of the most impor- tant characters in the Asphodel tribe, as you will find in my next letter. The principal differences of appearance in the Asphodel tribe are caused by two circumstances, the growing together of the sepals and petals into a tube, and the formation of a stem covered with leaves; the former alters the look of the flowers, the latter changes the whole aspect of the plant. You must therefore pay attention to this, before you discontinue your study of the tribe. To understand the first of these two circumstances you should endeavour to trace the gradations by which the growing together of the sepals and petals occurs. In the Onion you have seen that they are all distinct ; they are equally so in the Vernal Squill (Scilla bifolia), or in the Nodding Star of Bethlehem (Ornithogalum mutans) ; but in the wild Blue Hya- cinth, or Blue-bell, as it is often called (Hyacinthus non scriptus), they converge so as to form a tube; and in the curious Starch Hyacinth (Muscari) they are completely glued together. These gradations exem- plify most perfectly the passage from a spreading flower with separate segments to a tubular flower with all the segments united. The second peculiarity, that of forming a leafy stem, gives a much more different aspect to a part of the tribe. In the Asparagus, for example, which you perhaps only know in the state in which it is brought to table, the stem when full grown is repeatedly SP THE ASPHODEL TRIBE. 235 branched and covered with little taper green leaves ; the Asphodel itself has a simple stem clothed with very long blueish green channeled leaves; and cer- tain exotic plants called Dragon trees (Dracenas), form trees of considerable size, with stems having tufts of long broad leaves at their ends, in the manner of Palms. The latter, however, you are not likely to meet with, unless you should travel into countries more southern than Europe ; so that I do not anticipate any proba- bility of your being embarrassed by them in your notions of the Asphodel tribe. Our next subject will be Lilies, the most gorgeous, and Rushes the most mean, of Monocotyledonous plants. EXPLANATION OF PLATE XIX. I. Tae AspHopeLt Trispe.—1l. An umbel of the Streaked Onion (Allium striatum); a the spathe.—2. A flower spread open.—3. An anther viewed in front.—4. The same viewed from behind.—5. A pistil; a the place where the sepals and petals were cut off; 5 the ovary.—6. An ovary cut through horizontally.—6*. A ripe capsule, separated into valves; @ the remains of the flower.—7. A seed.—8. The same cut through, shewing the embryo, a, lying in the cavity of the albumen. II. Tue Orcuis Traise.—l. A flower of Fool's Orchis (O. Morio) seen in front; a the lip; 4 point of spur; ce lateral sepals; c* upper sepal; dd petals; e mouth of the spur; / bract covering the ovary. 2. The same viewed in profile; a lip; 4 spur; ce lateral sepals; e upper sepal; d petals; e ovary; / bract enveloping the ovary.—3. Column of Orchis Mascula; « the anther; 4 ¢ abortive anthers; d 236 pouch of the stigma; e the glutinous face of the stigma; / the mouth of the spur; g the suture by which the lobe of the anther opens.—4. An anther with its lobes forced open; apouch; &c abortive anthers; d passages in the pouch through which the pollen is supposed to communicate with the glutinous surface of the stigma; g g pollen- masses.—5. Back of an anther; a the passages in the pouch of the stigma; 4 the part where the anther was cut off.—6. A pollen-mass; a the gland.—(These are after drawings by Mr. Bauer.) : . eres gX ‘© ’ “* 2 pi } ; pm “8 Ee rae. ae | LIBRARY _ 2 OFTHE. — UNIVERSITY OF ILLINOIS ? (a , LY, Tay so Ccludsed Sittife i Sield: Lurula LETTER XX. THE LILY TRIBE—THE COLCHICUM TRIBE— THE RUSH TRIBE, (Plate AX 2) Tue characters of the Asphodel tribe are so simple, that I see no probability of your misunderstanding their application in more than two cases. Let your next inquiry then be how to avoid committing those errors. If you examine the flower of a Tulip (Plate XX. 1.), you will find so great a resemblance between its structure and that of the Asphodels, that you will not doubt of its belonging to their tribe. It has three sepals (fig. 1. b. b b.), which are of the same size and colour as the three petals (c. c. c.); from within these arise six stamens (fig. 2.), and in the centre of all is an ovary with three angles, three cells (fig. 3.), and a number of ovules in each cell. All this is quite in accordance with the structure of the As- phodel tribe. ‘The leaves, too, are extremely similar ; they are narrow strap-shaped things, with simple parallel veins; the underground bodies, moreover, from which the leaves and flowers shoot up, are true bulbs. Surely, then, the Tulip must belong to the Asphodel tribe. 238 LETTER XX. If the same accordance existed in the structure of all their other parts, it is clear, that to distinguish the Tulip from the Asphodel tribe would be unnecessary ; but there are distinctions in parts to which I have not yet adverted, and these distinctions are considered important. In the first place, the flowers of the Tulip are much larger, and more showy than you find in the Aspho- dels; and secondly, its seeds have not the same hard black brittle coat; but in its room you have a soft pale spongy integument. These are the two pomts upon which Botanists rely for the separation of the Tulip and its relations. It is to the Lily tribe that the Tulip belongs, toge- ther with the speckled Fritillaries, Crown Imperials, Day Lilies (Hemerocallis), and true Lzlies (Lilium), Dog’s-tooth Violets (Krythronium), and Twuberoses (Polyanthes), the most odoriferous of flowers. That the Lily tribe may be easily distinguished by the large size of its flowers, must be obvious, after naming such well known plants as the above, compared with which, the Asphodels, pretty as they are, sink into comparative insignificance. But the difference would be still more striking, if we added to the list the gigantic Lilies of Nipal, one of which is described by Dr. Wallich as growing ten feet high, with flowers large in proportion. It is, however, certain, that, notwithstanding the distinctions I have pointed out, the Lily tribe is very closely allied to that of Asphodels, with which it also coincides in its harmless qualities. We only know YW UL fi * THE COLCHICUM TRIBE. 239 its beauty ; it is in the eastern parts of Asia, among the Kamtchadales, &c. that it is applied to useful purposes. By those people, the bulbs of certain Lilies are used as a common food, and are stored up as an important part of their winter stock of pro- visions. The fibres of the leaves of both Asphodels and Lilies are sometimes strong enough to be manufac- tured into hemp. Among the former is classed the New Zealand Hemp (Phormium), of which such ex- tensive use is now made in the navy; and with the latter are stationed the plants called Adam’s Needle (Yucca), because their strong sharp-pointed leaves have been fancifully compared to a gigantic needle. A better name would have been the Needle-and-thread Plant, for by soaking in water, the fibres of the leaves may be separated from the pulp, without being torn from the hard sharp point, so that, when properly prepared, the leaves do really become needles, ready provided with a skein of thread. Since both the Asphodel and Lily tribes are so generally harmless, it becomes highly important that all possibility of confounding them with a poisonous order, which they in some respects resemble, should be guarded against. Meadow Saffron, called by Bo- tanists Colchicum, White Hellebore (Veratrum), and some other plants, have a structure very analogous to theirs. A calyx and corolla, each of three leaves of similar form and texture, half a dozen stamens, and a superior three-celled ovary, also characterise in part the natural order called the Colchicum tribe, to which 24.0 LETTER XX. those plants belong. Colchicum itself is very like a Crocus in flower, but its superior ovary prevents its being confounded with the tribe in which the Crocus is included. The species of Melanthium and Helo- nias are so similar in appearance to many of the Asphodel tribe, that they would no doubt be referred to the latter by a young Botanist. They, however, Meadow Saffron, and all the rest of the Colchicum tribe, may be recognised at once by three marks ; in the first place, they have no bulbs, but in their stead a solid knob or subterranean stem; secondly, their anthers are turned away from the stigma, splitting, and emitting their pollen on the side next the petals ; and lastly, the three carpels out of which the three- celled ovary is constructed, are separated at their points, so that there are always three styles instead of one style. These signs are what you must trust to in your determination of the Colchicum tribe; they may appear slight, and you may wonder why such trifling distinctions should serve to distinguish poisonous from wholesome orders; but with consi- derations of the causes of such a fact, we have no concern; all that it imports us to know is, that Providence has distinguished them by such minute marks, and has thus provided man with safe and unerring guides, if he will but learn-how to follow them. Between many other tribes of Monocotyledonous plants the distinctions are no stronger than those we have already examined, a proof of which I am now about to give you. THE RUSH TRIBE. 241 Rushes have so little apparent resemblance to Lilies, or Asphodels, or Meadow Saffron, that no one would ever dream of placing them all in the same natural group; and yet, if you examine a Rush, you will be surprised to see how slight is the difference that really exists between them. Some Rushes are humble rigid leafless herbs, with stiff slender wiry stems, and little clusters of dingy flowers: others are still more dwarfish in stature, but have weil formed leaves. An exceedingly common plant of the latter description is the Field Luzula (Luzula campestris, Plate XX. 2.). From a fibrous root rises a stem not more than five or six inches high, and which you can hardly distin- guish from the grass that it generally grows among in the meadows. Its leaves are narrow and grassy, and clothed with remarkably long hairs. At the top of the stem grow a few heads of chesnut-brown flowers, the structure of which you will hardly make out, ex- cept the sun shines, for it is then chiefly that the parts unfold. But if at that time you watch one of the brown clusters, you will be able to perceive, that each flower has six chesnut-coloured leaves, which spread like a star (fig. 3.), of which three are sepals, and three are petals. On their outside are two or three bracts (fig. 2. a. a.), so like them, as to be only distinguishable by their position. From within the flower rise six stamens ; and from between the latter an ovary (fig. 4.) with three angles, one style, and three stigmas. It fruit (fig. 5.) is an ovate body, containing only one cell, and three seeds (fig. 6. 7.), with a pale soft skin. 24.2 LETTER. XX. Now you will observe that in all that relates to the sepals, petals, and stamens, there appears to be nothing to distinguish a Rush from the Asphodel tribe; the fruit would seem essentially different, because of its haying only one cell; but in the true Rushes (Juncus) the fruit has three cells, so that that difference is unimportant. In fact if we neglect the texture, colour, and imperfect degree of develope- ment of the calyx and corolla, there will be hardly any means of separating Rushes from Asphodels, except the softness of the skin of their seeds. That the former do represent an inferior order of vegeta- tion, there can, however, be no reasonable doubt; we accordingly consider them among the most imperfect of regular Monocotyledons, Asphodels being an inter- mediate degree of developement, and Lilies the highest degree. Rushes are of so little use in any of the ordinary affairs of life, that it is scarcely worth occupying more time with their study. ‘The plants from whose stems are made what are called rush-bottomed chairs, rush- mats, and the like, are usually species of Club-Rush. and belong to the Sedge tribe, to which we shall now come very shortly. The orders of Monocotyledonous plants which we have examined, and several others that have not been mentioned, form what may be considered a natural subdivision, characterised by the perfect and com- plete manner in which their flowers are organized. In no case do they exhibit fewer than six divisions, of which three belong to the calyx, and three to the ANALYSIS. 943 corolla. If you examine with care the distinctions by which they are separated from each other, you will find that they are of this nature. Stamens & style separate 5 Stamens 6—The Narcissus tribe. Ona ( ¢ Stamens3—The Cornflag tribe. sfc ce < Stamens and style grown ) { together into a solid co- /. lumn . a ie The Orchis tribe. Seed-coat, soft and ¢ The Lily pale. Flowers large. tribe. Anthers with their ) Seed-coat black an¢Q 140 Asphodel facesturned towards kat d alc See 5 tribe. the ovary. Carpels ‘ f Ovary firmly united. Seed-coat soft and ) 77, push superior pale. Flowers mi- Sie nute, brownand dry I Anthers with their faces turned away from { The Colchi- the ovary. Carpels partially separate § cum tribe. EXPLANATION OF PLATE XX. Tue Liry Trise.—l1. Leaf and flowers of Ecluse’s Tulip (Tulipa Clusiana); abract; 4 sepals; ¢ petals.—-2. Stamens and ovyary.—3. The ovary cut through horizontally, shewing the ovules. Il. Toe Rusu Trispe.—l1. Stem, leaves, and flowers of the Field Luzula (Liuzula campestris).—2. A flower separate; @ a bracts.—3. An expanded flower seen from above.—4. A pistil, with its single style and three stigmas.—5. A ripe fruit—6. A seed.—7. The same cut through perpendicularly. LETTER XXI. THE BULLRUSH TRIBE—THE ARROW-GRASS TRIBE —THE DUCKWEED TRIBE. (Plate XXI.) In my last letter I mentioned that all the orders we have hitherto examined among Monocotyledonous plants have their flowers organized in a complete and perfect manner. ‘This letter will relate to some that are incomplete and imperfect. You will find that there are three degrees of organization in Monocoty- ledons, of which we have passed over one, are about to enter upon a second, and shall very soon arrive at the third. Bullrushes (Typha) are narrow flat-leaved tall plants, growing in marshes or pools of stagnant water, having their stems terminated by a dark cylinder, sur- mounted by a more slender yellow spike. ‘These plants represent a natural order, named after them, the Bullrush tribe, to which belongs a common wild marsh plant, called Bur-reed (Sparganium). The latter will furnish you with the means of studying the peculiarities of the natural order. If you regard the Bullrush ever so attentively, you will fail to discover, at any period of its growth, a Thee Yullrus hk bela Diuchwtta Tithe: 7) es yy) ZZ oh ttl. anal Purrwower Wa rhe Yt 001 =2tap. LIBRARY ~ OF THE UNIVERSITY OF ILLINGIS” THE BULLRUSH TRIBE. Q4.5 trace of flowers like those of the plants that have gone before. Upon the whole surface of the plant you find nothing different from leaves, except the dark cylinder, and the yellow spike on the top of it. It is at these parts that in reality the flowers are col- lected ; but they are so minute, and their organs are so delicate, that it requires a microscope, and a care- ful separation of them, to determine their real nature. The dark cylinder consists wholly of flowers contain- ing pistils only, or being fertile, and the yellow spike is composed of flowers containing nothing but sta- mens, or being sterile. I do not, however, propose to fatigue you by obliging you to anatomize a Bull- rush ; the same purpose will be effected, if you take the Bur-reed, which is similar in structure, but larger in all its parts. Branched Bur-reed (Sparganium ramosum, Plate XXI. 1.), is a wild plant, frequently found growing in ditches or pools, or by the wet banks of rivers. It rises to the height of two, or even three feet, and branches from the very ground. Its leaves, which are narrow, and shaped like a short straight sword- blade, have near the top of the stem a remarkably broad sheathing base. At the extremities of the branches appear round balls of flowers, some of which (b. b. fig. 1.), are bright green, and others (a. a.) bright yellow ; the latter being the most numerous, and placed above the others. The yellow heads consist of stamen-bearing, or barren flowers, and the green heads of pistil-bearing, or fertile florets. What happens in this case, occurs also in all instances in 24.6 LETTER XXI. which the stamens are separated from the pistils in different flowers on the same plant; we invariably find that the stamens are placed on the uppermost parts of the branch above the pistils, an arrange- ment which is no doubt provided, to facilitate the scattering of their pollen upon the stigmas. If they were placed below the pistils, it would be much more difficult for the pollen to reach the stigma, and con- sequently, the great end of the creation of the stamens would be almost frustrated. We find, however, that every thing is foreseen, and provided for by Provi- dence, with the same care in these little plants, as in the most exalted and perfect of the works of nature ; and that even so apparently useless and insignificant a weed as the Bur-reed, contains the most convinc- ing evidence of the worthlessness of the opinions of those who, denying the existence of the Deity, would have the world believe that livmg thimgs are the mere result of a fortuitous concourse of atoms, at- tracting and repelling each other with different degrees of force. . If we open one of the yellow balls, we find it con- sists of a great number of separate flowers, each of which has a calyx of three long-stalked jagged sepals ( fig. 2. a. a. a.), and six wedge-shaped anthers, which are heavier than the little slender filaments can well support. In the structure of their calyx, the flowers of the green heads do not materially differ from the latter (fig. 3.), the sepals are three in number, but broader and shorter, rolled round the pistil, and seated close THE ARROW-GRASS TRIBE. Q4'7 upon the receptacle, without any stalk. The pistil is an oval body, terminated by a deeply lobed stigma (fig. 3.), and having in its ovary but one cell, from the summit of which hangs a single ovule. The fruit contains one seed (fig. 6.), consisting of a mass of albumen (jig. 7.), at the further end of which lies a minute embryo (ig. 8.). It is obvious that this is an organization much more imperfect than that of the Monocotyledonous orders we have before examined; in room of an evident calyx and corolla, we have nothing but three scales, there is no trace of the number three im the ovary, aud the stamens and pistils are separated from each other. In the Bullrush itself, the imperfection is yet greater ; even the scales, which in the Bur-reed re- present the calyx, are wanting, and no hing appears in their room but a quantity of delicate black hairs. Nearly allied to the Bullrushes, like them useless to man, as far as we know, and equally inhabiting wet and spongy soils, are some little inconspicuous plants, called by the learned Triglochin, and by others Arrow-grasses. ‘These, and some allied genera, form an order called the Arrow-grass tribe (Juncaginee, Plate XXI. 2.), in which incompleteness of structure exist in a less degree than in the Bullrushes, for they have a calyx and corolla, and the usual number of stamens; but the former are more like scales than sepals and petals, and the ovary, although it has the usual ternary structure of Monocotyledons, is never- theless in an imperfect state. Marsh Arrow-grass (Triglochin palustre), is a little 248 LETTER XXI. inconspicuous plant, which does not grow above eight or nine inches high, and, both its leaves and stems being remarkable slender, is easily overlooked. Its curious structure will, however, amply repay the trouble of finding and examining it. It is common enough in wet meadows, or in other moist places, where the ground is covered with a sward of grass, from which you will never distinguish it, with- out employing all your power of observation. It is said to send out scaly runners, which end in little knobs, shaped like a scorpion’s tail. Its very narrow succulent leaves are of just the length and colour of those of many grasses, but they are taper, and not flat. When about to flower, it throws up from the midst of its leaves a little slender undivided stem (fig. 1.), which bears at its upper end a good many green flowers, loosely arranged at some distance from each other. Each of these flowers is constructed thus: On the outside are three concave blunt scales (fig. 2. a. a. a.), which constitute the calyx ; in the cavity of each of these there lies a roundish anther ( fig. 4. 6.), the face of which is next the scale, and consequently in the most unfavourable position possible for discharging its pollen upon the stigma. Within the calyx are three other scales, which are pressed close to the ovary, and which in like manner contain three anthers in their hollows; these scales are the petals; so that an Arrow-grass has three sepals, three petals, and six stamens. Its ovary is a long three-cornered body, having no style, and for a stigma nothing but a tuft of little hairs (fig. 2- THE DUCKWEED TRIBE. IAG & 3.6.). It may be separated with care into three carpels, at the bottom of each of which lies a single erect ovule, a great deal smaller than the cavity in which it is placed (fig. 3.). The fruit is a narrow three-cornered dry case, which divides into three slender parts, each of which is partly filled with a taper seed (fig. 7.). In almost all Monocotyledonous plants, a considerable quantity of albumen is provided for the nutriment of the young embryo, but the Ar- row-grass tribe is one of those which form an excep- tion to this rule. The embryo of these plants lies immediately below the seed-coat, and consists of a co- tyledon (fig. 8. ¢.), having near its base a small slit (a.) through which the young stem is protruded when the plant begins to grow. It is evident that this kind of structure is so unlike what we find in the Bullrushes, as to require no further explanation. What does require elucidation is the reason of the singular arrangement of the anthers, which I have just described; it does not at all appear for what cause they are so carefully embo- died in two hollows of the calyx and corolla, nor indeed how, under such circumstances, their pollen is ever to reach the stigma. I must confess my inabi- lity to explain the matter: you cannot do better than reflect upon it, until you hit upon some solution of the mystery. Far more simple than the previous tribes is that to which the Duckweed (Lemna) gives its name. In the former, whatever deficiency there might be in the parts of fructification, there was at least a stem and 250 LETTER XXI. leaves. But in Duckweed there is nothing but a fleshy floating green body, which looks like a green scale, and which is in reality a compound of both root and stem. Most people fancy that Duckweed never flowers: and many are they who have watched it all their lives without succeeding in discovering its blossoms. If, however, you will fix your eyes at- tentively upon a mass of it, on a still sunshiny day in the months of June or July, you will probably dis- cover exceedingly minute straw-coloured specks here and there on the edges of the plants; they have a sparkling appearance, and notwithstanding their mi- nuteness readily catch the eye. These are the anthers, and they being found, you have only to carry home the plants, and place them under a microscope, when all the secrets of their flowering stand revealed. Where the anthers have caught the eye, will be seen a narrow slit, out of which they peep; if you widen this slit (Plate XXI. 3. fig. 2.) with your dissecting instruments, you will be able to extract the blossom entire (fig. 3.); and you will have before your eyes the simplest of all known flowers, as Duckweed itself is the simplest of all known fiowermg plants. The flower consists of a transparent membranous bag, shaped like a water caraffe, and split on one side; within it are two stamens, and one ovary with a style and simple stigma. The fruit (fig. 4.) contains but one cell, in which are one or more seeds (fig. 5.) its shell is a thin cellular mtegument. Such are the simple means that Duckweed pos- sesses of propagating itself; means, however, which THE DUCKWEED TRIBE. Q51 appear to be abundantly sufficient, if we are to judge from the immense quantities which rise every year to the surface of our ponds. In Europe we have no other plant belonging to the same natural order ; but in tropical countries its place is occupied by a plant called Pistia, which is a sort of gigantic Duckweed, with broad lobed leaves Hke some Lichens, and a more highly organized flower. With these examples of imperfect Monocotyledo- nous plants, I must dismiss that part of the subject ; in my next letter I shall introduce you to the more in- teresting and important tribes which furnishes us with bread. EXPLANATION OF PLATE XXI. I. Toe ButtrusH Trree.—l. A shoot of Branching Bur-reed (Sparganium ramosum); @ a heads of barren flowers; 4 4 heads of fertile flowers.—2. A barren flower; aa a sepals.—3. A fertile flower. —4. Ananther seen from the side.—5. The same viewed from the edge.—6. A seed.—7. The same divided perpendicularly, with the embryo in one end of the albumen.—8. The embryo extracted. Il. Toe Arrow-Grass Trise.—1. A flower-spike of Marsh Ar- row-grass (Triglochin palustre.)—2. A flower; aaasepals; 6 stigma. —3. A perpendicular section of one of the cells of the ovary; 0 stig- ma.—4. A scale of the calyx a; with the anther, 4, lying in it.—5. An anther seen on the side by which it discharges its pollen.—6. A ripe fruit.—7. A perpendicular section of one of its cells, shewing the manner in which the seed hes in it.—8. An embryo; a the slit through which the stem is finally protruded; 4 the radicle; c the cotyledon. Ill. Tae Duckweep Trise.—1. Plants of furrowed Duckweed (Lemna trisulea) floating on water.—2. A plant magnified, and in flower at a.—3. A flower extracted from the slit in which it laid; a the membranous bag.—4. A fruit.—5. A seed. LETTER XXII. GLUMACEOUS PLANTS—THE GRASS TRIBE—THE SEDGE TRIBE. Plate XXII. wee For the natural orders forming the two different degrees of developement we have now considered, there is no collective name ; but for the third we have one in such general use, that we must not pass it by in silence. There are certain plants which are called GLiuma- cEous, because in place of calyx and corolla they have nothing but green or brown scales, named glumes, arranged alternately round a common centre. ‘The most remarkable of such plants are Grasses and Sedges, to the former of which I propose first to call your attention. The most common and the most useful of all the natural orders of plants is beyond doubt the Grass tribe ; wherever we cast our eyes, we are sure to see blades of grass springing up, if any vegetation at all can exist ; it is they that form that universal verdure which gives the northern parts of the world their peculiar charm, and which alone may console the inhabitants for the want of those other advantages