Part 2 — CHAPTER I.

PHANEROGAMOUS PLANTS—DICOTYLEDONÆ—I. DICHLAMYDEÆ.

§ I.—THALAMIFLORÆ.

In all the plants contained in this chapter the receptacle is a fleshy substance called the thalamus, or disk, which is surrounded by the calyx, and out of which the carpels or seed-vessels, the stamens, and the petals, all grow separately from each other. Sixty-five orders are included in this division, but I shall only describe those which contain plants which have been introduced into Britain, except where the orders chance to contain plants well known in commerce.

ORDER I.—RANUNCULACEÆ.

The plants belonging to this order are known by their numerous stamens, the anthers of which burst outwardly; by their carpels growing close together without adhering, except in one or two instances; and by the stem-clasping petioles of their leaves, which are generally deeply cut. The flowers when regular have five petals and five sepals, but they differ widely in shape, and the calyx of several of them is coloured so as to resemble a corolla. The seeds are fre quently cariopsides; and the plants abound in a watery juice which is acrid, and in most cases poisonous.

ORDER II.—DILLENIACEÆ.

This order resembles Raminculaceæ in having five petals, five sepals, and numerous stamens; but the anthers burst inwardly instead of outwardly, and there are never more than five carpels, and seldom more than two, which often grow into a berry-like fruit, as in the genus Dillenia from which the order takes its name. One species of this genus is occasionally seen in English hothouses, Dillenia speciosa. It has yellow flowers with the five petals apart at the base, and the sepals edged with white. The fruit consists of five carpels growing together with a sort of crown formed by the spreading stigmas. Another genus, some of the species of which are found in British greenhouses, is Hibbertia. The species are generally climbing plants, with flowers like those of Dillenia, but smaller, though H. dentata has the petals close together. The difference between the genera consists principally in the carpels, which in Hibbertia are distinct with long filiform styles curving inwards. All the plants contained in this order are evergreen exotic shrubs and trees with simple alternate leaves, and, with only two or three exceptions, the flowers are yellow.

ORDER III.—MAGNOLIACEÆ.

This order was divided by De Candolle into two tribes: viz. Illicieæ, the Aniseed tribe; and Magnolieæ, the Magnolia tribe. The first, which is now made a distinct order, under the name of Winteraceæ, contains three genera, only one of which, Illicium, is common in this country. The only hardy species of this genus, I. floridanum, the Florida Aniseed tree, has very dark purple flowers, which appear to be double from the great number of the petals, which are from twenty to thirty. The carpels are also numerous, and arranged so as to form a star. All the plants in this tribe are highly aromatic, and one species, Drimys Winteri, which has white fragrant flowers, produces an aromatic bark that is used in medicine.

The tribe Magnolieæ is distinguished by the fruit consisting of a number of carpels arranged so as to form a cone. There are six genera in this order, the most remarkable of which are Magnolia, Liriodendron, Talauma, and Michelia, the last genus consisting of stove trees, with very fragrant flowers, which are generally of a pale yellow, and only one species of which, M. Champaca, has been introduced.

Of these genera Magnolia is undoubtedly the best known; as nearly all the species are common in British gardens. This genus is divided into two sections, one containing the American Magnolias, and the other those from Asia, which are principally from China and Japan.

Fig. 104.—Flower of Magnolia conspicua opened to show the stamens and pistil.

The latter may be illustrated by Magnolia conspicua, sometimes called M. Yulan. The flower-buds are inclosed in a brown hairy case formed of two short bracts which become loose at the base, and are pushed off by the expanding flower. The flower itself (see fig. 104) is cup -shaped, and it is divided into six white fleshy Fig. 105.—The flower-bud of the Evergreen Magnolia. petals. The calyx consists of three sepals,—which fall off soon after the petals expand. In the centre of the flower is the receptacle, drawn up into a fleshy cone, with a great number of carpels attached to it, each of which has one cell containing two ovules, and a curved stigma. Around this cone grow the stamens, with very long anthers standing up like palisades, and very short thick filaments. The fruit is oval, with the ovaries somewhat distant from each other. The flowers appear before the leaves. The other Asiatic species are M. gracilis or Kobus, M. discolor, obovata, or purpurea, and M. fuscata; the former two forming handsome shrubs in the open ground, and having cup-shaped flowers which are white within and purplish on the outside, and the latter being a greenhouse plant, with brown very fragrant flowers.

The American species of Magnolia differ in having their flower- buds enveloped in one long spathe-like bract, as shown in fig. 105. The ovaries grow close together; and, when ripe, the carpels, which look like the scales of a fir-cone (see fig. 106), burst by a slit down the back; and the seeds, which are covered with a red juicy pulp, burst out, and hang down by a long white thread, which in the course of a few days withers away. The principal species of American Magnolias are the evergreen Magnolia, or Big Laurel (M. grandiflora); the Umbrella Tree (M. Fig. 106.—The ripe fruit and seeds of the Evergreen Magnolia. tripetala), which grows like a shrub with several stems rising from the ground; the Cucumber-tree (M. acuminata), the flowers of which are bluish and the leaves pointed; Beaver wood (M. glauca), the flowers of which are small, and the leaves covered with a glaucous bloom; M. auriculata, M. pyramidata and M. macrophylla, which are nearly allied to the Cucumber-tree; and M. cordata, the flowers of which are yellowish. All these Magnolias produce their leaves before their flowers; and in this also they differ from M. conspicua, the flowers of which appear before the leaves.

The genus Liriodendron contains only two species differing slightly in the leaves. Both are lofty trees, with cup-shaped flowers of six petals curiously stained with red and yellow, and bent back at the tip. The calyx consists of three sepals, which remain on as long as the petals. The fruit is cone-shaped, but the carpels, which are each furnished with a kind of wing, instead of opening when ripe, fall with the seed enclosed.

The genus Talauma differs from Magnolia principally in the carpels, which open irregularly by valves; and in the number of petals, which vary from six to twelve. Only two species are common in British hothouses, T. Candolli, commonly called Magnolia odoratissima; and T. pumila, sometimes called M. pumila and sometimes Liriodendron lilifera: both are natives of Java, and both have cream-coloured, or yellowish flowers, which are remarkably fragrant at night.

ORDER IV. ANONACEÆ.—THE CUSTARD-APPLE TRIBE.

The hardy plants belonging to this order, that are well known in Britain, were formerly included in the genus Anona; but now the only species retained in that genus are stove plants, natives of the West Indies, with yellowish brown or dark purple flowers, the calyx of which is in three sepals, and the corolla in three or six thick fleshy petals, and which have numerous stamens with large angular anthers, and very short filaments. The carpels are numerous, but they grow altogether into a fleshy eatable fruit, divided into many cells, each containing one seed. This fruit is called the custard apple or sour sop in the West Indies; and it differs in flavour in the different species, but the most delicious kind is produced by A. Cherimolia, a native of Peru. The hardy species included in Anona by Linnæus have been separated from that genus, and formed into another under the name of Asimina, the principal distinction between them being in the fruit; which in the genus Asimina consists of two or three berry-like carpels growing together, not eatable, and each containing many seeds. A. triloba, the hardiest species, is a large shrub, with dark brownish purple flowers. The plants in this order are all aromatic.

ORDER V.—MENISPERMACEÆ.—THE COCCULUS TRIBE.

All the plants contained in this order are climbing exotic shrubs, generally with drooping racemes of small delicate flowers, the male and female flowers being on different plants. The number of sepals and petals varies in the different genera, and sometimes the petals are wanting. The stamens frequently grow together into a central column; and the fruit is a drupe or one-seeded berry, generally scarlet, but sometimes black. The principal plants in this order which are known in England, are, Menispermum canadensis (the Canadian Moon Seed), a very ornamental hardy, climbing, shrub; Cocculus palmatus, the root of which is a tonic drug, called Columba root; Anamirta Cocculus, which produces the berries called Cocculus indicus in the shops, which are said to be used in porter to give it an intoxicating property; Schizandra coccinea, a greenhouse climber with scarlet flowers; and Kadsura japonica, a climbing shrub with white flowers and red berries, which proves quite hardy in the open air. Kadsura, Schizandra, and three other genera, little known in this country, have been formed into a new order under the name of Schizandriaceæ. The qualities of all these plants are tonic.

ORDER VI. BERBERIDEÆ.—THE BERBERRY TRIBE.

Fig. 107.—Details of the flower and fruit of the common Berberry, partly magnified.

Each flower of the common Berberry (Berberis vulgaris) has on the outside three little bracteal scales, which are reddish on the back, and soon fall off. The flower itself consists of a corolla of six petals, and a calyx of six sepals, though as these divisions are all of the same size and shape, and of the same colour and texture, it is not very easy to distinguish the calyx from the corolla. The petals will however be found on examination to have each two little glands at the base, as shown at a in fig. 107, which the sepals are without. The sepals are placed exactly behind the petals, so that the one appears a lining of the other; and, being concave, the petals serve as a kind of cradle to the stamens, as shown at b. There are six stamens, which have broad filaments; and instead of anthers the filaments are widened at the tip, and each contains two cases for the pollen (c); these cases are each furnished with a valve-like lid (d), which opens and curls back when the pollen is ripe. The pistil (e) is pitcher-shaped, with a very thick style, and a flat stigma. It stands erect, while the stamens are spread out so as to be a long way from it, but they are so irritable that the slightest touch makes them spring forward and discharge their pollen on the stigma, afterwards falling back into their former places. The flowers are yellow, and they are produced in long drooping racemes; and they are succeeded by red oblong berries (f), each of which contains two seeds (g). The receptacle, with the stamens growing out of it from beneath the pistil, is shown at i. The common Berberries are all deciduous shrubs, with simple leaves, which are produced in tufts, as shown in fig. 108, each leaf being delicately fringed with hair-like teeth. Each tuft of leaves has two or three sharply-pointed stipules, which are easily distinguished from the leaves, by their margins being without teeth; and below these are three spines, which, when young, are soft and look like folded leaves, but which, when older, be come hard, and sharply pointed. These spines are considered by some botanists to be abortive branches. There are many different kinds of Berberry, which differ principally in the size of the flowers and in the colour of the fruit; but which also vary in the size and shape of the leaves, and in the manner in which they are toothed.

Fig. 108.—Flowers of the Berberry, natural size.

The Ash-leaved Berberries were formed into a separate genus called Mahonia by Nuttall; and this genus has been adopted by Professor de Candolle, and other botanists. Dr. Lindley, however, includes all the species in the genus Berberis, and he has been followed by Mr. George Don in his new edition of Sweet’s Hortus Britannicus. Whether the genus Mahonia be a good one or not, the plants composing it are very distinct from the true Berberries. The leaves of the Mahonias are evergreen, and pinnate; and the leaflets instead of being fringed with fine hairs, are broadly serrated, the points being tipped by a sharp prickle or mucro (see a in fig. 109); and the petiole is articulated, and somewhat stem-clasping at the base (b). The flowers are in erect racemes, and smaller than those of the Berberry; they are also more globular, being less widely opened, and the petals are without any glands. The filaments of the stamens have two hair-like teeth just below the lobes of the anthers; and the fruit has from three to nine seeds in each berry; while the Berberries have only one or two. There are many kinds of Magnolia, but the handsomest is M. Aquifolium, a hardy shrub, with dark green shining leaves, like the holly. All the species both of Berberis and Mahonia have yellow flowers; and the Mahonias all flower very abundantly, and very early in spring.

Fig. 109.—A compound leaf, being that of Mahonia aquifolium.

The principal other plants belonging to this order are, Nandina domestica, a very pretty shrub with white flowers, from China, which requires a greenhouse in England; several species of Epimedium, some of which are from Japan, with purple and white flowers; a few species of Leontice, pretty plants with yellow flowers; and a plant called Diphylleia cymosa, with white flowers and blue berries, a native of North America. All these plants are easily recognised by their broad stamens, and the curling back of the valves of their anthers.

ORDER VII. PODOPHYLLACEÆ.—THE MAY-APPLE TRIBE.

This order contains only two genera; viz., Podophyllum and Jeffersonia; both of which have a calyx of three or four sepals, and a white corolla of from six to nine petals. Podophyllum has numerous stamens, and a fleshy berry with only one cell, which does not open when ripe; and Jeffersonia has eight or nine stamens, and a capsule which opens all round the apex. Podophyllum peltatum is the May-apple, and its fruit is eatable when ripe, though very acid; the leaves are very large, and peltate, that is, with the footstalk attached to the centre; and Jeffersonia diphylla is a little plant, without any stem but that which supports the flower. Both are natives of America, where they are found in moist shady places.

ORDER VIII. HYDROPELTIDEÆ.

This order, which many botanists combine with the preceding one, also consists of only two genera; viz., Cabomba and Hydropeltis; and of these Cabomba aquatica is a stove aquatic, and Hydropeltis purpurea is a hardy water plant, with peltate leaves, and dull purple flowers.

ORDER IX. NYMPHÆACEÆ.—THE WATER-LILY TRIBE.

Fig. 110.—The flower, leaf, and seed-vessel of the White Water-lily, greatly reduced in size.

The principal genera in this order are Nymphæa, Euryale, Victoria, Nuphar, and Nelumbium. The flowers of the common White Water-lily (Nymphæa alba) consist of numerous sepals, petals, and stamens, all of which might be mistaken for petals, being principally distinguished by their colour. The sepals, (a in fig. 110,) are green on the outside, but they are white within, and of the same fleshy substance as the petals (b). The stamens (c) look like narrow yellow petals; they are pointed, and bear the pollen in two lobes near the point, which open longitudinally when ripe. The inner row of stamens are without anthers, and form a kind of vandyke edging to the pistil, as shown at e. The pistil consists generally of sixteen carpels, growing together into a vase-like, many-celled berry, as shown at d; the spreading stigmas, which have also grown together, forming a kind of lid. The carpels are completely enclosed by the receptacle which rises up round them, and forms a thick fleshy covering, as shown at f. The seeds are numerous, and they are covered with a thick leathery skin. The embryo is small, and it is surrounded by a great mass of floury albumen. The leaves (g) are large and nearly round; and the main root, which is called a rhizoma, is thick and fleshy, and is, indeed, an underground stem. There are several kinds of Nymphæa, the most remarkable of which is the Egyptian Lotos (N. Lotos), the flowers of which are white tinged with pink; and both the roots and seeds of which are eaten. Euryale is a genus of South American Water-lilies, generally with small flowers, and large rough leaves; and Victoria regina, also a native of South America, is perhaps the most magnificent Water-lily in the world; the leaf, which is peltate and turned up at the brim, being of a deep crimson on its lower surface, is upwards of six feet in diameter; and the flowers are more than a foot in diameter, with a corolla of more than a hundred large white petals tinged with pink.

The genus Nuphar consists of only three or four species, the most common of which is N. lutea, the common yellow Water-lily, a native of Britain. The flower has a cup-shaped calyx of five large yellow sepals, the tips of which curve inwards. The petals are small, truncate, and flat, with a small pore on the back of each; and the stamens, which are very numerous, have broad petal-like filaments. They differ, however, very much in appearance from those of the genus Nymphæa, and they are differently placed, springing from the base of the vase-like pistil, and not from the upper part. There are from sixteen to twenty carpels enclosed in the dilated receptacle, to which the stigmas form a ray-like cover; and each carpel contains several seeds. The leaves are somewhat cordate, and rise rather above the surface of the water, and the rhizoma, or root-stem, is very thick. The common yellow Water-lily, or Brandy-bottle, as it is sometimes called from the smell of its flowers, is common in every part of England, and it is generally found in small ponds or ditches. The other species are mostly natives of North America.

The Indian Lotos (Nelumbium speciosum) differs so much from both the preceding genera, as to be considered by some botanists to form a different natural order. The sepals and petals are so intermingled in the flower as to be scarcely distinguishable; but the filaments of the stamens are less broad and petal-like. The disk is still elevated, but it has lost the vase-like form, and it appears as though the top had been abruptly cut off; while the carpels are no longer joined together, but are plunged each separately in the fleshy receptacle, or torus, with their stigmas quite distinct. As the carpels are only half immersed in the torus, and thus show their styles and stigmas, they have a very singular and bottle-like appearance; and the torus, when they are taken out of it, looks like a piece of honey-comb. The rhizoma is white and fleshy. The stalks of the flowers and leaves rise considerably above the water; and thus the flowers have not the graceful appearance of those of the Nymphæa, which seem to repose on the surface. The leaf is very large, being sometimes one or two feet in diameter; and it is always peltate, with the stalk exactly in the centre. There is only one seed in each carpel of the Nelumbium; and this seed, which has no thick leathery skin, is of about the size and shape of an acorn. It is very good to eat, having a sweet milky flavour, and in botanical construction it resembles the common bean, having no albumen, but a very large embryo. This is probably the reason why it has been supposed to be the bean of Pythagoras, and why it is called the Sacred Bean of India. One of the Hindoo fables represents the god Bramah as first appearing in the form of a child, cradled on a Lotos leaf, and floating on the waste of waters.

There are several kinds of Nelumbium, one of which, a native of America, has double yellow flowers; and they all require a stove in England.

ORDER X. SARRACENIEÆ.—THE SIDE-SADDLE PLANT.

There is only one genus in this order, which can never be mistaken for any other, from the pitcher-shaped petioles of its leaves, and its singular flowers. It is a native of Canada, but it rarely flowers without a stove in England. It is a dwarf plant, and it is thus easily distinguished from the Chinese Pitcher plant, which grows eight or ten feet high, and which belongs to quite a different order.

ORDER XI. PAPAVERACEÆ.—THE POPPY TRIBE.

This tribe contains several genera, all of which have a thick glutinous juice when broken, which poisons by stupifying. The genera most common in British gardens are Papaver, the Poppy; Argemone, the Prickly Poppy; Meconopsis, the Welsh Poppy; Sanguinaria, Blood-root; Eschscholtzia; Hunnemania; Rœmeria; Glaucium, Horned Poppy; Chelidonium, Greater Celandine or Swallow-wort; Hypecoum; Platystemon, and Platystigma. Most of these plants are either annual, or last only two or three years, and they have all very handsome flowers, which are generally large and of showy colours.

The common Corn Poppy (Papaver Rhœas) has a showy flower, the corolla of which consists of Fig. 111.—Flower, leaf, and seed-vessel of the common Poppy. four very large scarlet petals, the outer two much exceeding the others in size (see a in fig. 111). The calyx is green, and it is divided into only two sepals, (see b,) which fall off soon after the expansion of the flower. The petals are all curiously crumpled in the bud, and they present quite a wrinkled appearance when the flowers are first opened. The stamens are very numerous, and the anthers, which are black, are of the kind called innate; that is, the filament is only attached to them at the lower part (c). The seed-vessel of the Corn Poppy is, when ripe, a dry leathery capsule (d) with numerous angles, each angle indicating a carpel; for the capsule of the Poppy, though one-celled when ripe, consists, in fact, of a number of carpels grown together. The remains of these imperfect carpels are perceptible in the little valves shown at f, which open at the top of each to discharge the seed when it is ripe; and in the slightly-peaked cover (e), which consists of as many stigmas grown together as there appear to have been carpels. When the capsule is cut open (as shown in the capsule at g, from which the fourth part has been removed), remains of the carpels will be found in several projections from the sides, which partially divide the inside of the capsule into several imperfect cells, in which the young seeds are formed; though none of these portions reach the centre. The ovules, when first formed in the ovary, are attached to these projections, which are called parietal placentæ; but as the seeds ripen they become loose, and if a dry Poppy-head be shaken, they will be found to rattle. The leaves of the Corn Poppy are what is called pinnatifid, (see h in fig. 111,) that is, they are so deeply cut as to appear almost in separate leaflets; and the whole plant (except the petals and the capsule) is covered with short bristly hairs (i), which stand out horizontally.

The Opium Poppy (Papaver somniferum) differs from the Corn Poppy in several respects. First, the whole plant is glabrous, that is, devoid of either hairs or bristles; the capsule also is much larger and more fleshy in an unripe state, and the crown-like lid is smoother, and curved over like a plume of feathers, (see a in fig. 112.)

Fig. 112.—The flower, bud, leaves, and capsule of the Opium Poppy, much smaller than the natural size.

The fleshiness of the unripe seed-vessel of the Poppy puzzled me extremely at first, as I knew that the ripe capsule of this Poppy is always dry and leathery; but it was soon explained to me, that this fleshy substance is, in fact, an elongation of the receptacle or disk, which rises up round the carpels, and envelops them, in the same way as the disk of the Water-lily grows round the pistil and carpels of that plant, but which dries up as the fruit ripens. The leaves of the Opium Poppy (b) differ from those of the Corn Poppy, in being much broader, and only slightly cut or notched; they are also glaucous, that is, of a bluish or sea-green, and they are clasped round the stem at their base (as shown at c). All the Papaveraceæ abound in a thick glutinous juice, which in the Poppies has the colour and appearance of milk, and which possesses stupifying properties; but in the Opium Poppy this juice is particularly abundant. Opium is, in fact, procured by wounding the fleshy capsule with a sharp knife, and suffering the milky juice which exudes to dry in the sun; after which it is scraped off with a blunt instrument, and pressed into cakes for sale. The opium of commerce is produced in hot countries; but even in England, any one who chooses may procure a small quantity of opium, by wounding the fleshy capsule of the common White Poppy when it is about half ripe. A milky juice will issue from the wound, which when dry becomes opium, and would be poisonous if taken in excess. The capsule of the White or Opium Poppy has, when ripe, a little window-like opening under each stigma for the discharge of the seeds, which contain abundance of oil, and may be safely eaten, though the rest of the plant is poisonous.

There are many different kinds of Poppy; but they all agree in the corolla of their flowers being in four petals, or in some number divisible by four; and in the calyx, which is generally in two sepals, dropping off as soon as the flowers expand. All the species abound in a milky juice, which poisons by stupifying; and they all agree in the general construction of the capsule, with its fleshy envelop and its stigma-formed lid. The petals are always crumpled in the bud, and they fall very soon, so that the beauty of the flowers is very short-lived. The flower-buds droop; but when the flowers expand, the stalk becomes erect, and remains so while the capsule containing the seeds is ripening; a wise provision, common to many plants, to prevent the seeds from falling too soon. The calyx of most of the Poppies is in only two sepals; but in the two showy perennial species, called P. orientale and P. bracteatum, the calyx is in three sepals.

Among the other plants belonging to the order Papaveraceæ, may be mentioned the Horned Poppy (Glaucium luteum), which, instead of an obovate capsule, has a long horn-like pod, divided into two cells, the valves opening from the top to the bottom. The whole plant is glaucous; and the leaves, which are broad and notched, clasp the stem at their base, like those of the Opium Poppy. The Prickly Poppy (Argemone mexicana) has the whole plant covered with strong prickles; the leaves are wrinkled and curved up at the margin; the calyx has three sepals; and the capsules are in four or five valves, the stigmas forming a kind of cross at the top. The stem and leaves when bruised give out a thick glutinous juice, which, instead of being white like that of the Poppy, is yellow.

The Eschscholtzia is the last genus of the order Papaveraceæ that I shall mention here, and it deserves a particular description, both from its popularity and the beauty of its flowers, and from the singularity of its botanical construction. The bud when it first appears is enfolded in a calyx, which is pointed at its upper extremity, and appears to have a kind of rim near its base. When the flower is ready to expand, the calyx detaches itself all round from the projecting rim, and rises gradually without opening, till the flower actually pushes it off. The detached calyx resembles an extinguisher, and hence it is called calyptrate, which has that signification. The flower is cup-shaped; there are four petals and four stigmas, two of which are much longer than the others. The capsules are elongated like those of the Horned Poppy, but they are distinguished by the projection of the flat fleshy disk at their base; they are two-valved and two-celled. The leaves are glaucous, and finely cut. There are three species, or perhaps varieties, which differ principally in the degree of enlargement of the receptacle or disk. They have all large fleshy roots, which bleed copiously if wounded, and for this reason the plants are difficult to remove unless when quite young.

ORDER XII. FUMARIACEÆ.—THE FUMITORY TRIBE.

The flowers of plants of this order are so peculiar in their shape, as when once seen to be easily remembered. There are two small sepals, which soon fall off, and four petals of an irregular shape, two of them being drawn out into a kind of spur. There are six stamens, and the fruit is silique-formed. The plants have somewhat of a smoky smell, and when broken yield a watery juice. The principal genera are Fumaria, Corydalis, and Diclytra.

ORDER XIII. CRUCIFERÆ.—CRUCIFEROUS PLANTS.

The Cruciferous plants form so natural an order, that when one of them has been described the others may be easily recognised. They have all a separate calyx and corolla, each in four divisions; the four sepals being placed Fig. 113.—The flower and stamens and pistil of the Sea-kale, to illustrate the Cruciferæ. alternately with the four petals, the latter forming a cross (as shown at a in fig. 113), whence the name of Cruciferous, which signifies cross-bearing. There are six stamens (b), two of which are much shorter than the others; and two carpels with one style, and a capitate or divided stigma. The seed-vessel is a kind of pod, either short and broad, like that of the Shepherd’s Purse (fig. 114), where it is called a sillicle; or long and narrow, Fig. 114.—A Sillicle. like that of the Cabbage, which is called a silique. The two valves of the silique open naturally when ripe, from the bottom curving upwards, (see fig. 115,) and the seeds are deposited on a thin membrane between the cells, which is the dissepiment. All the Cruciferæ, from abounding in nitrogen, have an unpleasant smell when decaying, like putrid flesh; and when cultivated, they even in a wild state require abundance of animal manure; hence, they are generally found near human habitations, or where cattle are kept. When wild, they have generally acrid properties; and though these are in most cases softened by cultivation, yet they are still perceptible in the Fig. 115.—A Silique. roots of the Horse-Radish, and the common Radish, and in the leaves and seeds of Mustard, and the different kinds of Cress, &c. This acridity, however, is never so great as to be injurious; and Cruciferous plants, particularly if their texture be succulent and watery, may always be eaten with perfect safety. Even those which, in a wild state, are tough and stringy, such as the wild Cabbage and the root of the wild Turnip, become excellent by cultivation; and all Cruciferous plants are so extremely nourishing as to be considered next in this quality to animal food.

Among the many garden flowers which belong to this order, few are more popular than the common Wallflower (Cheiranthus Cheiri). Its hardiness, and the facility with which it is raised and cultivated—the gaiety of its flowers, their profusion, and their delightful fragrance, combine to make it a general favourite; and I think I cannot take a flower to illustrate the order which is more generally known and liked. The flowers of the Wallflower (see fig. 116, a) consist of four petals, each of which is furnished with a long tapering point, called the claw (b), and a broad flat part called the limb (c). The claws of the petals are buried in a calyx of four sepals, placed alternately to the petals, and somewhat swelled out at the base, (see d). The stigma (e) is two-lobed, and forms a kind of notched head. There are six stamens, which appear at first to be all nearly of the same height, but on examination it will be found that two are somewhat shorter than the others. The seed-vessel is of course the lower part of the pistil; which, after the petals drop, becomes elongated into a somewhat cylindrical silique, which contains several flattish seeds.

Fig. 116.—Flowers of the Wallflower.

The Brompton Stock (Mathiola incana), and the Ten-week Stock (M. annua), differ from the Fig. 117.—Flower of the Brompton Stock. Wallflower principally in the shape of the stigma (see fig. 117, a). The petals have also rather longer claws, and hang looser, as shown at b. The Virginian Stock (Malcomia maritima) has a roundish silique, and only one stigma, which ends in a long tapering point. The Candytuft (Iberis umbellata) has a short pod or sillicle, which has the appearance of being cut off at the point, and which contains only one seed in each cell; and the outer two petals of the flower are somewhat larger than the inner ones. Many other Cruciferous plants might be described, but I think my readers will have pleasure in seeking them out themselves, and examining them, to discover their points of agreement and of difference; particularly as, though the order is such a very large one, the flowers of all the plants are so much alike, that no one can be in doubt respecting their alliance.

ORDER XIV.—RESEDACEÆ.—THE MIGNONETTE.

The common Mignonette (Reseda odorata) was once included in the order Capparideæ; but it is now made into a little order by itself, called Resedaceæ. The flower, as is well known, is by no means remarkable for its beauty, though it is for its fragrance; but when examined botanically, it will be found well deserving of attention, from the singularity of its construction. It has a green calyx of six sepals, which are only remarkable for being what botanists call linear; that is, long and narrow, and of equal width throughout—a very unusual form for sepals. Within the calyx are the petals, six fleshy, green, heart-shaped bodies; with a hair-like fringe round the lower part, and with the upper part cut into a tuft of segments so different in colour and texture from the lower part, that it is scarcely possible to believe that they are one. This upper part of the petal is called the crest, and it is pure white; the segments into which it is divided appearing to be a great number of delicate little petals growing out of a fleshy heart-shaped disk.

It is worth gathering a flower of Mignonette, and taking off one of the petals to look at it in a microscope; and one of moderate size, which may be bought for 12s. at the Bazaars, will be quite sufficient for the purpose. It will then be found that the fleshy part of the petal is as easily detached from the rest of the flower as petals usually are, but that it is so firmly fixed to the crest as to be inseparable without cutting. The disk is, however, dilated and curiously drawn out between the stamens which are inserted in its base, and the petals, as though to form a barrier between them. It will be quite visible when the petals are removed, as it is as firmly attached to the stalk of the flower as the petals are to their crests. Between this elevated part of the disk and the calyx is a green substance which looks like a part of the stalk, but which belongs to the disk. There are twelve stamens, with large orange-coloured anthers, which are at first erect, but afterwards bend forward horizontally; and in the middle of the stamens is the ovary, an oblong hollow cell, with a three-lobed stigma, forming three erect points. Inside the ovary from each stigma runs the kind of nerve called the placenta, and to each nerve are attached three rows of seeds. The substance of the ovary is always soft and leaf-like, even when it becomes a ripe capsule; and though it is greatly swelled out and bladdery, it retains the same leaf-like and somewhat wrinkled appearance to the last. When the capsule is ripe, each of the pointed lobes, which formed its upper extremity, opens down the middle, thus forming a curious three-cornered mouth for the discharge of the seed. The flowers form what is called an upright raceme, springing from a succulent main stem, which is, however, somewhat woody at the base. The plant indeed, though treated in England as an annual, is a shrub in the plains of Barbary, of which it is a native; and even in this country it may be made to assume the character of a small tree, by keeping it during winter in a hothouse or greenhouse. I was very much surprised to find that Mignonette has been introduced barely a century; and it seems difficult to imagine how those of our ancestors who were fond of flower-gardens contrived to do without it. I have only to add that there are several species of Reseda, one of which (R. luteola) is a British plant used in dyeing, and is called Dyer’s Weed, or Weld.

ORDER XV.—DATISCEÆ.

There is only one genus of three species, which are coarse hardy perennials, having the appearance of hemp; and only grown in England in botanic gardens.

ORDER XVI.—CAPPARIDEÆ.—THE CAPER TRIBE.

This order is divided into two sections, viz., the true Capers, and the Cleomes; both of which have very long and conspicuous stamens. The common Caper (Capparis spinosa) has a large and handsome flower, with a distinct calyx and corolla, both in four parts. The petals are white, and so delicate in their texture as to fade in a few hours if exposed to the sun; and the stamens, which are very numerous, have rich purple filaments. In the centre is the pistil, with a very long stalk, and the ovary at the point, instead of at the base, with no style, and a very small stigma. In consequence of this curious construction, the seed-pod, which is fleshy, and hangs downwards, appears to be on a much longer stalk than the flower. The shrub is spiny, and in its natural habitat it grows among stones and rocks. It is the unopened flower-buds that are pickled. The genus Cleome consists principally of annuals, with very handsome flowers, which have very long stamens, and a pistil of the same construction as in Capparis, but the fruit is a dry capsule. The anthers of the stamens are often enfolded in the flowers before they are fully expanded, so that the filaments appear bent, till at last they open fully and hang down. There are a few other genera in the order, but they are little known in England.

ORDER XVII.—FLACOURTIANEÆ.

The plants belonging to this order are mostly Indian plants, little known in Europe.

ORDER XVIII.—BIXINEÆ.—THE ARNOTTA TRIBE.

Bixa Orellana is a shrub, a native of South America, which requires a bark stove in England. It has pink flowers with five petals, and a green calyx of as many sepals. The stamens are numerous; but they are on rather short filaments. The leaves are very large and heart-shaped. The fruit is a berry, and the pulp in which the seeds are immersed, when dry, is the Arnotta used in colouring cheese.

ORDER XIX.—CISTINEÆ.—THE CISTUS TRIBE.

There are only four genera in this order, viz., Cistus, Helianthemum, Hudsonia, and Lechea; and though there are almost innumerable plants comprised in it, they nearly all belong to the first two.

All the plants belonging to the genera Cistus, the Rock-rose, and Helianthemum, the Sun-rose, have showy flowers, each having five petals, which are crumpled in the bud like those of the Poppy; they also resemble the petals of the Poppy tribe in falling almost as soon as they have expanded, as every one must have observed who has noticed the flowers of a Gum-Cistus. The calyx in both Cistus and Helianthemum generally consists of five sepals, two of which are larger and of a paler green than the others, and grow a little below them; and this calyx remains on after the petals have fallen, and, indeed, till the seed is ripe. In the Gum-Cistus, however, and some other species, the two outer sepals are wanting. There are a great many stamens, which are rather short, and form a tuft in the centre of the flower, surrounding the pistil, which has a round flat-headed stigma, a rather long style, and an ovary divided into five cells. The seeds are numerous, and each has a separate footstalk, by which it is attached to the placentas, which, in the Cistus tribe, are in the centre of the ovary, and not proceeding from its sides, as in the Mignonette. The capsule, which remains covered with the calyx till it is quite ripe, divides into five or ten concave valves, each having a placenta, to which the seeds were attached, in its centre. The seed of any plant belonging to the order Cistaceæ, is remarkable when cut open for the great size of the embryo enclosed in it, and the curious manner in which it is curled up. The embryo is the germ of the future plant, and it is usually buried in a great mass of albumen, or floury matter intended for the nourishment of the young plant, till its roots are in a fit state to supply it with nourishment. In the seed of the Cistus, there is scarcely any albumen; but in its stead a long narrow embryo, coiled up like a sleeping snake.

The Gum-Cistus is generally called, in the nurseries, Cistus ladaniferus; but it differs materially from the plant so named by Linnæus, as that has a ten-celled capsule, while the capsule of the common Gum-Cistus (which botanists call C. Cyperius) has only five cells. The leaves also differ, the under surface of those of the one kind being woolly, and of the other smooth; the one is also a native of Spain and Portugal, and the other, as the specific name imports, of Cyprus. Both species, and also C. Ledon, exude from their stems and leaves, a kind of gum or resin called Ladanum or Labdanum, which is used in medicine. It is from this gum having been formerly always mixed with opium when that drug was dissolved in spirits of wine, that the name of laudanum is given to the tincture of opium.

The two genera, Cistus and Helianthemum, differ chiefly in the capsule, which in the latter genus is triangular and one-celled, opening into three valves, each of which has a narrow dissepiment down its centre. To prevent any confusion arising from the use of these terms, I may here observe that when a capsule is divided into several cells, having no communication with each other, the membranes that separate them are called dissepiments; while the nerve-like part of it to which the seeds are attached is named the placenta. Sometimes the placenta is merely a nerve running down the side of the capsule, when the capsule is one-celled, without any dissepiment or division; and sometimes the dissepiment does not spread across the capsule so as to divide it into different cells, but only projects a little way from the side towards the centre, as in the one-celled capsule of the Poppy, (see p. 260,) and in that of the Helianthemum, when the seed-vessel opens naturally into different parts, as in the Gum Cistus, these parts are called valves, as are also the parts of pods, as shown in the curled-up valves of the silique, fig. 115, in p. 268.

To return to the Helianthemum, the species of this genus are generally used for rockwork, as they are all dwarf plants, though many of the genus Cistus are large shrubs four or five feet high. The English name of the Helian themum, Sun-rose, is very appropriate, as the flowers will only expand in sunshine, and will even decay in the bud without opening at all, when gloomy weather lasts for several days.

ORDER XX. VIOLACEÆ—THE VIOLET TRIBE.

The order Violaceæ, though not a large one, contains several genera, but the most interesting is the genus Viola, which includes among many other species the Sweet Violet (Viola odorata), and the Heartsease (V. tricolor). The flowers of both species have many claims to admiration, but they do not add the charm of regularity in construction to their other attractions, as, in fact, few flowers are less symmetrical. The flowers of both are nearly alike in their details; but to avoid confusion, I will describe them separately. The calyx of the Heartsease consists of five pointed distinct sepals, two of them rather smaller than the others. These sepals are not attached, as in most other plants, at their base; but so as to leave nearly a quarter of their length standing up, far beyond the place where they are fixed to the receptacle, so as to form a sort of border or cup round the stem, and between it and the flower. The sepals are green, but they are edged with a delicate whitish membrane at the margin, scarcely to be seen without a microscope. There are five petals which are also irregular in their construction, two of them being much larger than the others, and generally of a different colour; and one even of the other three being quite different in form to its companions. The two large petals at the back of the flower, which in the common Heartsease are generally dark purple, are laid over each other, and behind the two below them. These two side-petals, which form the centre of the flower, are both furred at the base; and the lower petal, which is placed between them, has its claw drawn out behind into a spur, which passes between two of the sepals; and which, when the flower is looked at from behind, appears to be part of the calyx. The furred part of the two side-petals forms a triangular, roof-like opening, peeping out of which, is seen a small pale-green ball-like substance, which a fanciful imagination might liken to a head looking through a dormer window; and this is all that is to be seen in place of the usual apparatus of stamens and pistils. As all seed-producing flowers must have stamens and pistils, and as it is well known that Heartseases and Violets do produce seed in abundance, it is clear that these important organs are not wanting; but where are they? It is easy to guess, after being so far initiated in the mysteries of botany, that the little globular body is a part of the pistil; but where are the stamens? It is necessary to pull the flower to pieces to discover them. Commencing this work of destruction, which I always feel remorse at perpetrating, for I love flowers too well not to feel pain at destroying them; commencing this work, I repeat, the petals and the sepals must be carefully removed from the stem; a task of some little difficulty, as both sepals and petals are firmly attached to the receptacle, and the lower petal must have its spur opened with a pin to avoid hurting the delicate organs it contains. When the outer coverings of calyx and corolla are thus both removed, the seed-producing organs will be discovered, and it will be found that they consist of five very curiously-formed stamens, with as singular a pistil, in their centre. The stamens have no apparent filaments, and the anthers, which seem to be inserted in the receptacle, look like seeds, each tipped with a bit of brown skin, and having what appears to be a white rib in front. This rib is the anther; and the broader part is the dilated filament, which is drawn out beyond it, on both sides, and above, so as to form the brown tip above the anther already mentioned. Two of the anthers have each, in addition to these peculiarities, a long tail, which the spur of the lower petal concealed, when the flower was in a perfect state. The pistil consists of a large ovary, full of ovules, with a narrow style, which is drawn out into the hollow globular termination which is seen through the triangular opening in the flower. The globe has an opening in front, under which is a kind of lip, which looks like a shutter let down to show the opening; and though, from its thick fleshy nature, it looks like a stigma, it is only the outer covering of that organ, for the stigma lies within the opening. In this manner the stigma and anthers are completely concealed; and thus it will be seen, that nothing can be more complex and intricate than the construction of the flowers of the Heartsease.

Who could suppose that all these elaborate details would be necessary to illustrate so simple a flower as that of the Violet? And yet the construction of the flowers of the Violet and those of the Heartsease are essentially the same. The sepals of the Violet are extended at the base, like those of the Heartsease, and the corolla consists of the same number of petals, which are equally irregular in their form, though not in their colour; the lower petal is drawn out, in the same manner, into a spur, which is much longer than that of the Heartsease, though the rest of the flower is smaller. The stamens are formed with the same regular irregularity, only the tails of the two irregular ones are larger and stronger, in the same proportion as the spur is larger which is intended to conceal them. The pistil is of the same shape, with the same curiously constructed and perforated style, which is bent in its narrow part and swelled out into a hollow globe at the tip; and in both species, the ovary is one-celled with three parietal placentas, that is, with three nerve-like projections from the sides of the capsule, having four rows of seeds attached to each. The capsule looks like a smooth shining berry, and it remains partially shrouded by the calyx, till the seeds are ripe; when it bursts open with an elastic spring, and divides into three valves, each of which has the placenta bearing the seeds in its centre.

In all these points the Heartsease and the Violet are alike; but they differ materially in the leaves, which in the Violet are broad and heart-shaped, without stipules; but in the Heartsease are small and ovate, with such very large and deeply-cut stipules, that they are by most persons mistaken for the leaves. I may here be asked what are stipules, and in what do they differ from leaves? In answer to the first question, I can only inform my readers that stipules are generally little leaf-like bodies, which seem to act as attendants upon leaves, as bracts seem to wait upon flowers; but in what they differ from leaves, except in size and shape, I have not been able to learn. Even Dr. Lindley in the last edition of his Introduction to Botany, says, “What stipules really are is not well made out.”

The Heartsease and the Violet differ also in their habit of growth. The Violet is a creeping plant with no stalks but those supporting the flowers, while the Heartsease stands erect, with a thick square stem, so strong, that, notwithstanding its succulent nature, it may be trained like a little tree.

ORDER XXI. DROSERACEÆ—THE SUN-DEW TRIBE.

There are three genera in this tribe that are well known: Drosera, the Sun-dew; Dionæa muscipula, Venus’s Fly-trap; and Parnassia palustris, the Grass of Parnassus; all bog plants. The species of the genus Drosera are remarkable for the curious manner in which the leaves and peduncles are coiled up when they first appear, and in which they slowly unroll themselves as they grow. They are also beautifully edged with a sort of fringe of glandular red hairs, and a fluid exudes from these glands which makes them always appear as though covered with dew. The common Sun-dew (D. rotundifolia) is a British plant, with short roundish leaves; but other species are natives of New Holland and North America; and several of them have long slender leaves like threads. Venus’s Fly-trap (Dionæa muscipula) is a native of Carolina, in North America; the leaves are curiously formed of two lobes, which close and open as if hinged, and they are furnished with glandular hairs, which are so extremely irritable as to make the leaves close at the slightest touch, and thus to imprison any unfortunate insect that may be within the lobes. The petiole is so much dilated as to look like a leaf, but the real leaf consists of only the two roundish lobes edged with teeth that form the Fly-trap. The flowers are white, and they are produced in corymbs. The corolla has five petals, which do not fall off when they wither, but roll up so as to look like the cocoon of an insect.

ORDER XXII. POLYGALEÆ—THE MILKWORT TRIBE.

The genus Polygala is well known from the very handsome greenhouse plants which it contains. The flowers at first sight appear to resemble those of the Sweet Pea, having two wings like a standard, and a sort of keel; their construction is, however, very curious, and so complicated, as to be very difficult either to describe or to understand. The calyx is said by modern botanists to consist of five sepals, three of which are green and two lilac, these last being the part that resembles the standard of the Sweet Pea. The corolla is also said to consist of five petals, two of which stand erect, and the other three grow together to form the keel. The latter have their upper part cut into a kind of crest, like that of the Mignonette. Below the crest, the united petals form a kind of hood, under which are arranged the eight stamens, four on each side. The stamens themselves are as remarkable as the other parts of the flower; the filaments grow together into a thin kind of leaf, and each anther has but one cell, and opens by a pore at the apex. The pistil is also very curiously formed, as the style and stigma have the appearance of a gaping monopetalous corolla. The fruit is a flat two-celled capsule, which, when ripe, opens by two lips, separating from each other, and showing a seed within each cell. Even the seeds are not like other seeds, for each has a large white protuberance at one end, called a corancula.

ORDER XXIII. TREMANDREÆ.

Slender New Holland shrubs, with the habit of Heaths, rarely met with in British gardens.

ORDER XXIV. PITTOSPOREÆ.—THE PITTOSPORUM TRIBE.

The principal genera included in this order are Pittosporum, Billardiera and Sollya, all resinous shrubs, with alternate leaves without stipules, and the sepals and petals, each five in number, and laid over each other like scales in the bud. The seeds are numerous, and immersed in fibrous pulp. The commonest species of Pittosporum is P. Tobira, a native of China, easily known by its thick leathery leaves, the midribs of which are strongly marked, and whitish. The flowers are erect, and produced in cymes or heads; and the petals are united into a tube with a spreading limb. The capsule is one-celled, and two or three valved, with an imperfect dissepiment in the centre of each valve; and the seeds are numerous, and buried in a resinous fibrous pulp. The Billardieras are generally climbing shrubs, with pale greenish bell-shaped, and almost erect flowers, which are produced singly or in pairs, and which have the tips of their petals turned back. The fruit is a fleshy berry, with a shining skin of a deep blue, and it is called the Apple Berry in Australia, of which country the species are natives. This fruit is said to be eaten in Australia, but it seems difficult to imagine how this can be the case; as though the outer part of the berry is of a soft spongy nature, it is dry and insipid; and there is no internal pulp, for the seeds lie loose in the cells. In Sollya heterophylla the flowers are drooping, on long and very slender pedicels, and they are produced in cymes. The corolla is campanulate, with the tips of the petals not recurved, and the anthers are much shorter than in Billardiera. The fruit is a soft fleshy berry, divided into two cells, each containing two rows of seeds immersed in pulp, and when cut open, it smells strongly of turpentine. The plant generally called Sollya linearis has a dry and leathery pericardium; and for this reason and on account of the spreading of its anthers, it was placed by Mr. Cunningham in a new genus, which he called Cheiranthera.

ORDER XXV. FRANKENIACEÆ.—THE FRANKENIA TRIBE.

The genus Frankenia consists principally of the British weeds called Sea Heath; and the other genera included in the order are seldom seen in British gardens, from the seeds which have been imported seldom arriving in a state fit for vegetation.

ORDER XXVI.—CARYOPHYLLACEÆ—THE CARNATION TRIBE.

The plants belonging to this order have so strong a family likeness to each other as to be easily recognised; and they are all distinguished botanically by the swollen joints of their stems, and their opposite undivided leaves, which are generally connate, that is united, and sheathing the stem. The order is divided into two sections, viz.: Sileneæ, in which the sepals are united into a tube, and which section includes the genera Silene, Dianthus, Saponaria, Lychnis, and Agrostemma; and Alsineæ, in which the sepals are either quite distinct, or only slightly cohering at the base, and which includes Stellaria, Arenaria, Cerastium, Spergula, and several other British weeds. The Chickweed was called by Linnæus Alsine media, but the genus Alsine is now united to Stellaria.

Fig. 118.—The Carnation.

The Wild or Clove Carnation (Dianthus Caryophyllus), which may be considered the type of the order, has an erect stem, swollen at the joints, with connate leaves, (see a in fig. 118). The flower, when single, consists of five petals, each with a very long narrow claw (b), and a rather broad limb or blade (c) serrated at the edge. The calyx (f) is tubular, with five vandyked teeth, which are in fact the tips of five sepals, into which the tube of the calyx may be easily divided with a pin. The tubular form of the calyx is admirably contrived to support the long claws of the petals, and to keep them in their proper places; particularly when the flowers are double, as the weight of the petals in that case frequently bursts the tube of the calyx. Every one fond of pinks and carnations must have observed the miserable appearance of the flower when thus deprived of its natural support; and to prevent the premature destruction of prize-flowers by this misfortune, professed florists sometimes slip a curiously-cut piece of card-board over the bud, which remains on after the expansion of the flower, and prevents the petals from falling out of place. Some florists tie the calyx round with thread, instead of using a pasteboard ring, which answers the same purpose. At the base of the calyx are two, four, or six leafy appendages (g), resembling bracts, which are called the calycine scales. These imbricated scales are, however, only found in the genus Dianthus. There are ten stamens (d) unequal in height, but none of them longer than the ovary round which they are placed. The ovary and the stamens are concealed in the cup of the flower, but the former is furnished with two styles, terminating in two long stigmas (e), which project beyond the flower, and which, when magnified, appear delicately fringed.

The genus Dianthus includes the Carnation, the Pink (Dianthus plumarius), the Chinese Pink (D. sinensis), the Sweet William (D. barbatus), and many ornamental flowers. Of these the Sweet William has the claws of its petals bearded; the flowers are produced in bundles or fascicles; and the calycine scales are so numerous and awl-shaped, that they give a bristly appearance to the flowers. The different species of Soap-wort (Saponaria) differ from Dianthus, in having no calycine scales; and this is also the case with the berry-bearing Campion (Cucubalus baccifer), the fruit of which is a fleshy capsule or berry, which finally becomes black, and has a singular appearance in the centre of the cup-like calyx, which remains on till the fruit is ripe. The flower of this plant is white, and the petals have a two-cleft limb. All the numerous species of Catchfly (Silene) are also without calycine scales, and the petals are generally deeply two-cleft; but they are distinguished by having a crown of petal-like scales in the throat of the corolla. There are also three styles instead of two; and the capsules are three-celled at the base, ending in six teeth at the top. The species have frequently a glutinous frothy moisture on the stem, in which flies sometimes become entangled, and hence the English name of the genus. One species, the Bladder Campion (S. inflata), has been used as food, and its young shoots, when boiled and sent to table like Asparagus, are said to have the flavour of green peas. The different species of Lychnis and Agrostemma resemble Silene closely in every respect, except in the styles, which are five, instead of three; these two genera, Viscaria, and Githago, differ very slightly from each other; and several of the species are known by different names: thus Ragged Robin (Lychnis flos cuculi) is made by some botanists an Agrostemma; the Corn-cockle is sometimes called Githago segetum, and sometimes Agrostemma Githago; the common Rose Campion is called sometimes Lychnis, and sometimes Agrostemma; and the Rock Lychnis, or Red German Catchfly, sometimes Lychnis Viscaria, and sometimes Viscaria vulgaris.

ORDER XXVII.—LINACEÆ.—THE FLAX TRIBE.

The order Linaceæ is a very small one; and, indeed, it consists principally of the genus Linum. The Flax was formerly included in the Caryophyllaceæ, which it resembles in having five petals, five sepals, and five stamens; but it also resembles the Mallow in its capsules, and in its stamens growing together at the base; and the Cistus in its persistent calyx, and the disposition of its sepals. These links, which connect one order with another, and make them appear alike but not the same, form, I think, one of the most interesting parts of the Natural System. We are led on from one gradation to another, by scarcely perceptible shades of difference through the vegetable kingdom; and, indeed, through the whole system of creation: the beautiful harmony, and unity of design, visible throughout, bearing the strong impress of the Divinity whose power has made the whole.

The common Flax (Linum usitatissimum), though in its appearance only an insignificant weed, is a plant of great benefit to man. The fibres of the stem are used to make linen, and the seeds (linseed) are crushed for oil. The flowers are blue, and have five regularly-shaped petals, which are twisted in the bud; and a distinct calyx of five pointed sepals, two of which grow from a little below the others, as in the Gum Cistus; and, as in that plant, the calyx remains on till the seeds are ripe. There are five stamens, the filaments of which grow together slightly at the base, and there are five little points like filaments without anthers, rising between the stamens. The petals are connected with the ring formed by the united filaments, and sometimes the petals themselves grow slightly together at the base. The capsule consists of five two-celled carpels, grown together; each cell containing one seed, and each carpel terminating in a rather slender style, tipped with a ball-like stigma. When ripe, the capsule opens naturally, by dividing into ten valves, to discharge the seeds; which are flat and shining, with a large embryo. These seeds are called Linseed in the shops, from Linum, the botanical name of the plant; and, as is well known, they are not only used for various purposes, but oil is expressed from them. The stem of the common Flax, though it is only an annual, consists of woody fibre, like that of a tree in its young state; and it is this fibrous part that makes the yarn for thread, after it has been separated from the fleshy part, by steeping the stems for a long time in water. The perennial Flax (Linum perenne), which, as its name imports, lasts several years, differs in little else from the common kind, except that its sepals are obtuse, and its leaves are much smaller and narrower. Both these are natives of Britain. There are many other species, some of which have yellow flowers.

ORDER XXVIII.—MALVACEÆ.—THE MALLOW TRIBE.

All the plants belonging to Malvaceæ bear so much resemblance to each other, that this order may be considered a very natural one; and it is one very remarkable for the botanical construction of its flowers. In some respects it resembles Linaceæ, quite enough indeed to show clearly the chain by which they are so beautifully linked together; but in others, it differs so decidedly as to show how completely they are distinct. Fig. 119, which represents the Fig. 119.—The flower, stamens, and pistils of the Althæa frutex. flower and seed-vessel of the Althæa frutex (Hibiscus syriacus), will serve to show the chief peculiarities of this order. The calyx consists of five sepals, below which is an involucrum of six or seven leaflets, which have the appearance of a second calyx. The corolla is cup-shaped, and consists of five petals, which are close together at the base, and this is peculiar to the genus Hibiscus. The capsule is round and somewhat convex, being nearly in the shape of what is called a batch-cake, as shown at c; it consists of five carpels grown together, each containing many seeds; and when ripe, it bursts naturally into five valves, each of which has a dissepiment down the centre. The filaments grow together very curiously, inclosing the styles, and forming a column in the centre of the flower, which is the distinguishing mark of the Malvaceæ. Some of the stamens are shorter than others, and as part of each filament is detached, the anthers form the fringe-like border to the column, shown at d. The anthers are kidney-shaped and one-celled, and this is another of the characteristics of the order; but the styles are terminated by five ball-shaped stigmas, like those of the Linum. There are many kinds of Hibiscus; but perhaps the best known are: H. rosa sinensis, the species which is so often represented in Chinese drawings, and the petals of which are so astringent, that they are said to be used in China by the men to black their shoes, and by the women to dye their hair; and the Bladder Ketmia (H. Trionum), which takes its English name from its inflated capsule. All the plants belonging to the order Malvaceæ have a central column, round which are placed numerous carpels, which grow together and form a many-celled capsule; and they all have kidney-shaped, one-celled anthers. They have also always an involucrum below the calyx, but this involucrum differs in the different genera. In the genus Malva, the involucrum consists of three leaflets, which in the common Mallow (Malva sylvestris) are oblong. The petals are wedge-shaped, and they are what botanists call auricled; that is, they are set so far apart at the base that light can be seen through them. The stamens are all of nearly the same height, and they form a kind of bunch round the styles, which are pointed. The capsule consists of a circle of woolly-looking carpels growing close together, but so as to be easily detached with a pin, and each fitting into a little groove in the receptacle, in which they are placed. As the seeds ripen, the involucrum falls off, but the large loose-looking calyx remains on. There is only one seed in each carpel; but as there are generally eleven carpels in each capsule, each seed-vessel contains this number of seeds. The leaves are lobed and toothed; and the whole plant is covered with long hairs, which are disposed in little star-like tufts.

The genus Malope closely resembles the Mallow; except that the petals are not wedge-shaped, and that it has a still larger calyx, the long sepals of which shroud the capsule as the involucre of the filbert does the nut. The involucrum is composed of three broad, heart-shaped leaflets, which remain on till the seed is ripe. The petals are also not so even along the margin; and the carpels are so disposed as to form a cone-shaped capsule, instead of a flat one.

The genus Lavatera has the leaflets of the involucre joined to the middle, so as to form a kind of three-cornered saucer below the capsule; and the capsule itself is completely covered with a part of the receptacle, which is dilated, and curved down over it. Lastly, the genus Althæa, the Marsh Mallow, has the involucrum cleft into six or nine divisions, and the carpels united into a globular capsule. The Hollyhock (A. rosea) belongs to this genus. Many other genera might be mentioned, but these will suffice to give my readers a general idea of the order, and of the points of difference which distinguish one genus from another. Among the exotic plants belonging to the order is the cotton tree (Gossypium herbaceum), the cotton being the woolly matter which envelops the seeds in the capsule. All the Malvaceæ abound in mucilage, and they all have woody fibre in their stems.

ORDER XXIX.—BOMBACEÆ.—THE SILK COTTON TREE TRIBE.

This order is closely allied to Malvaceæ, and it differs principally in the tube formed by the stamens being divided into five bundles near the top. It includes the Baobab, or Monkey-bread (Adansonia digitata), said to be the largest tree in the world; the Screw tree (Helicteres Isora), so named from its curiously-twisted fruit; Carolinia princeps; the Silk Cotton tree (Bombax Ceiba); and the Hand-plant (Cheirostemon platanoides),—this is the Hand-plant so named from the lobes of its leaves resembling fingers,—all stove plants in Britain.

ORDER XXX.—BYTTNERIACEÆ.—THE BYTTNERIA TRIBE.

This order is divided into five sections, which some botanists make distinct orders. It is very nearly allied to Malvaceæ, but the anthers are two-celled. The principal genus in the first section (Sterculieæ) is Sterculia, which has several carpels distinct and arranged like a star: the species are trees with large handsome leaves which are articulated at the base, and axillary panicles or racemes of flowers. The second section (Byttnerieæ) contains among other plants Theobroma Cacao, from the fruit and seeds of which Cocoa and Chocolate are prepared. The third section (Lasiopetaleæ) is well known in England, by the pretty Australian shrubs included in the genera Thomasia and Lasiopetalum, the leaves of which have their under surface downy, and generally brown. The fourth section (Hermannieæ), and the sixth (Wallichieæ), contain no plant common in English gardens; and the fifth (Dombeyaceæ) is best known by Astrapæa Wallichii. The qualities of all the plants in this order are mucilaginous.

ORDER XXXI.—TILIACEÆ.—THE LINDEN TRIBE.

The only genus belonging to the natural order Tiliaceæ which is easily to be procured in Britain is that of Tilia, the Lime trees. The common Lime (Tilia europæa) is generally a tall, well-formed tree, with rather broad leaves, which are heart-shaped at the base, tapering at the point, and serrated at the margin: they are also smooth on the outer surface, thin, and of a light and delicate texture; below there is a little tuft of hair at the angle of the veins. The flowers are produced in cymes or compound Fig. 120.—The flowers and seed-vessel of the common Lime tree. umbels (see fig. 120); and their main pedicel appears to spring from one long entire bract (a). The calyx is in five sepals, and it falls off before the corolla, which is composed of five pale yellow petals, which are very sweet-scented.

The stamens are numerous, and the filaments separate, bearing two-celled anthers, which burst by long slits. The ovary has only one style, the tip of which is cleft into five small stigmas; and it is divided into five cells, each containing one or two ovules. The fruit or capsule (b) is round, and has a leathery skin, covered with a soft down; and when ripe, the cells often become united so as to form one, with only one or two perfect seeds in the whole capsule, the other ovules proving abortive. The whole plant abounds in mucilage, and the sap when boiled affords sugar. The inner bark is so tough and fibrous, that it is used for making what are called bast mats: it being first rendered flexible by steeping it for a long time in water. The wood is of very fine texture, but soft and white, and it is thus admirably adapted for carving. The American Limes have a small scale at the base of each petal of the flower; but the other differences between the species are very slight.

ORDER XXXII.—ELÆOCARPÆ.—THE ELÆOCARPUS TRIBE.

East India shrubs and trees, little known in Britain. “The hard and wrinkled seeds of Elæocarpus are made into necklaces in the East Indies, and, set in gold, are sold in our shops.”—(Hook.)

ORDER XXXII*.—DIPTEROCARPÆ.—THE CAMPHOR TREE TRIBE.

There are two kinds of Camphor, one produced by boiling the branches of a kind of laurel, and the other (the Camphor of Sumatra) is found in large pieces in the hollow parts of the branches of Dryobalanops Camphora, one of the species included in this order. None of these trees have been introduced into Britain.

ORDER XXXIII.—CHELONACEÆ, OR HUGONIACEÆ.

Small trees and shrubs, natives of the East Indies and Madagascar; only the genus Hugonia is known in Britain.

ORDER XXXIV.—TERNSTRŒMIACEÆ.—THE TERNSTRŒMIA TRIBE.

The principal plants in this order common in England are Gordonia, Stuartia, and Malachodendron. Gordonia Lasianthus, the Loblolly Bay, is a small evergreen tree, with white flowers, about the size of a rose. It is a native of America; and Stuartia and Malachodendron are beautiful low trees or shrubs, with large white flowers from the same country. The flowers have five large petals; the stamens are numerous, with the filaments growing together at the base, and attached to the petals; and there are five carpels more or less connected. Gordonia has its five sepals leathery, and covered with a silky down; its stamens almost in five distinct bundles, a five-celled capsule, and its seeds each furnished with a wing. Stuartia has a permanent calyx, five-cleft, but not parted into distinct sepals, with two bracts at the base, and a woody five-celled capsule, with seeds without wings; and Malachodendron (which was formerly called Stuartia pentagynia) has a calyx similar to that of Stuartia, but the edges of the petals are curiously crenulated, and there are five distinct carpels, each containing only one seed. Some botanists include the Camellia and the Tea in the order Ternstrœmiaceæ.

ORDER XXXV.—CAMELLIACEÆ.—THE CAMELLIA TRIBE.

There are two genera in this order, the Camellia and the Tea. The flower-bud of the Camellia is inclosed in a calyx of five, seven, or nine concave sepals, on the outside of which are several bracts, which remain on till the flower has expanded, but which are distinguished from the sepals by their dark brown colour. The sepals and the bracts are laid over one another like scales, and thus the flower lies encased in a complete coat of mail. The single flower is cup-shaped, with five, seven, or nine petals, which are sometimes joined together at the base. The stamens have long slender filaments, which either grow together at the base, or are separated into several bundles. The anthers are elliptical and versatile; that is, they are poised so lightly on the filament as to quiver with the slightest breeze. The ovary is of a conical shape, and it has three or five slender styles, ending in as many pointed stigmas, and growing together at the base. The capsule is three or five-celled; and when ripe it bursts into three or five valves, in the middle of each of which is a dissepiment, which, before the capsule opened, was attached to an axis or column in the centre. The seeds are large and few, and they are fixed to the central placenta. There is no albumen, but the embryo has two large, thick, oily cotyledons, which look as if they were jointed at the base. The leaves are leathery, dark-green and shining, and they are ovate in form, ending in a long point, and sharply serrated. The flowers spring from the axils of the leaves, and grow close to the stem without any footstalk; and the leaf-bud for the ensuing shoot grows beside the flower-bud.

I have above described the Camellia japonica, from which nearly all the Camellias in British gardens have sprung; but there are some other species. The finest of these is C. reticulata, which has very large, loose, widely-spreading flowers, of a remarkably rich crimson. The leaves are oblong, flat, and reticulately veined, being of a much finer texture than those of C. japonica. The ovary is two or four-celled, and it is covered with fine silky hairs. C. maliflora is a very beautiful species with small semi-double flowers, coloured like an apple blossom. This Camellia is by some botanists thought to be a variety of C. Sasanqua, an elegant species with white fragrant flowers; but the ovary of the first is smooth, and that of the second covered with hairs, which most botanists consider a specific difference.

The Tea tree (Thea viridis) is very nearly allied to the Camellia; but there are many points of difference. The flower of the Tea tree has a footstalk; the calyx has only five sepals; the filaments of the stamens do not grow together; the capsules are three-seeded; and the dissepiments are formed by the edges of the valves being bent inwards, instead of being attached to a central axis. The leaves are also much longer than they are broad, and they are of a thinner texture and pale green; and the outside of the capsule, which is furrowed in the Camellia, is quite smooth in the Tea tree. It is said that both the green and the black Tea are made from the leaves of Thea viridis; but there is another species called Thea Bohea, which has smaller leaves, and is a more tender, and less vigorous-growing plant. The young leaves of Camellia Sasanqua, and some of the other Camellias, are also dried, and mixed with the tea. All these plants are natives of Japan and China, and require a slight protection in England during winter.

ORDER XXXVI.—OLACINEÆ.—THE OLAX TRIBE.

Exotic trees from the East and West Indies, little known in Britain. Heistria coccinea, a native of Martinique, is said to be the Partridge wood of the cabinet-makers.

ORDER XXXVII.—AURANTIACEÆ.—THE ORANGE TRIBE.

Fig. 121.—Flower and seed of the Orange.

The natural order Aurantiaceæ contains fourteen genera; but the only one I think my readers will feel an interest in is the genus Citrus. This genus comprises, among several other species, C. medica, the Citron; C. Limetta, the sweet Lime; C. Limonum, the Lemon; C. Paradisi, the Forbidden fruit; C. decumana, the Shaddock; C. Aurantium, the Sweet Orange; and C. vulgaris, the Bitter or Seville Orange. to these may be added C. nobilis the Mandarin Orange, the fruit of which is reddish, and which parts naturally from its rind, which is sweet, and may be eaten. All the species agree in having a tube-like calyx, scalloped into five short teeth, and a flower of generally five fleshy petals, (see a in fig. 121), though the number occasionally varies from four to nine. These petals are elliptic in shape, concave, and always widely opened. In the centre of the flower are the stamens, varying from twenty (which is the ordinary number) to sixty; the anthers are two-lobed, and oblong, and the filaments are somewhat thickened at the base, and united there into several small bundles (b), but free above. The pistil has a somewhat globular ovary, with a cylindrical style, termi nating in a stigma, which is slightly raised in the centre. The disk in which the stamens are inserted, forms a ring round the ovary. The fruit (fig. 122), which is considered by botanists to be a kind of berry, is in fact a seed-vessel with numerous cells, divided by dissepiments and a central placenta (a); the cells being the quarters of the Orange, the dissepiments the divisions between them, and the placenta the central pith. When the flower first expands, the ovary, if cut open and examined, will be found to be divided into several cells, each containing two rows of ovules. As in the preceding genera, however, many of these ovules become abortive; and as the cells fill gradually with cellular pulp, the seeds become detached from the placenta, and buried in it. The seeds themselves are very interesting; they are covered with a thick wrinkled skin, and they show distinctly the hilum (c in fig. 121), the chalaza (d) and the raphe or connecting cord between them, parts which are seldom to be distinguished in seeds with the naked eye.

Fig. 122.—Leaf and fruit of the Orange.

The leaves, calyx, and petals of the Orange, if held up to the light, appear covered with little dots. These dots are cells, covered with a transparent membrane, and filled with a kind of oil, which is exceedingly fragrant. The rind of the fruit is covered with similar cells, filled with a pungent oily liquid. The leaves are smooth and shining; and they are articulated; that is, they can be separated from the petiole or footstalk without lacerating them. In most of the species, the petioles are winged; that is, they are dilated into little leaves on each side (see d in fig. 122). The different species vary chiefly in the number of stamens, the thickness of the rind, the shape of the fruit, and in the wings of the petioles. In the Citron these wings are wanting entirely, and instead of them there are spines in the axils of the leaves; there are generally forty stamens, and the rind of the fruit is very thick. In the sweet Lime, the petioles are slightly winged, and there are about thirty stamens; the fruit is small and round, with a slight protuberance at one end like that of the Lemon, and the pulp is sweet. In the Lemon the petioles are somewhat winged, the flowers have about thirty stamens; the fruit is oblong, with an acid pulp, and a thin rind. The Sweet Orange has winged petioles, about twenty stamens, and a fruit with a thin rind and sweet pulp; and the Seville Orange differs principally in having a thicker rind and bitter pulp. The China, St. Michael, and Malta Oranges, with many others, are all varieties of the Sweet Orange (Citrus Aurantium); and there are many other species, which I have not thought it necessary to describe.—All the species above-mentioned are natives of Asia, and most of them of China, but they have been so long cultivated in Europe and America, as to have become almost naturalised.

ORDER XXXVIII.—HYPERICINEÆ.—THE HYPERICUM TRIBE.

The genus Hypericum, or St. John’s Wort, agrees with the orange in having its leaves full of transparent cells; but these cells are filled with a yellow, resinous juice, resembling gamboge in its medicinal properties, and having a very disagreeable smell. There are five petals in the corolla; and the calyx consists of five sepals, which are unequal in size and shape, and joined together for only a short distance. Like the orange the filaments grow together at the base, in separate clusters or bundles; but in the Hypericum these clusters are so perfectly distinct, that the stamens may be readily separated into three or five bundles (according to the species), by slightly pulling them. The capsule is dry, and of a membrane-like texture, and it consists of three or five carpels, containing many seeds, and each having a separate style, and a pointed stigma. The flowers are very showy, from their large golden yellow petals and numerous stamens. The genus Androsæmum, the Tutsan, or Park-leaves, has been separated from Hypericum on account of its fruit being one-celled and one-seeded, with a fleshy covering, which yields a red juice when pressed. H. calycinum, with large yellow flowers and five tufts of stamens, is the handsomest species; but H. perforatum is the true St. John’s Wort, which the country people used formerly to gather on midsummer eve, as a preservative against witchcraft.

ORDER XXXIX.—GUTTIFERÆ.—THE MANGOSTEEN TRIBE.

The only genus in this order that contains plants interesting to the English reader is Garcinia; and the most remarkable species are G. Mangostana, the Mangosteen, said to be the most delicious fruit in the world, and G. Cambogia, the tree producing the gamboge, which is a kind of gum that oozes out from the stem. Both are natives of the East Indies.

ORDER XL.—MARCGRAAVIACEÆ.

Exotic shrubs, mostly natives of the West Indies, with spiked, or umbellate flowers, and alternate leaves. Very seldom seen in Britain.

ORDER XLI.—HIPPOCRATACEÆ.

Exotic arborescent, or climbing shrubs, generally with inconspicuous flowers. Natives of the East and West Indies.

ORDER XLII.—ERYTHROXYLEÆ.—THE RED WOOD TRIBE.

Exotic shrubs, and low trees, remarkable from the redness of their wood, but with small greenish flowers. The leaves of Erythroxylon Coca possess an intoxicating quality, and are chewed by the Peruvians, in the same manner as the Turks take opium.

ORDER XLIII.—MALPIGHIACEÆ.—THE BARBADOES CHERRY TRIBE.

Several species of Malpighia, the Barbadoes Cherry, are found occasionally in our stoves. The corolla of these plants, when closed, bears considerable resemblance to that of a Kalmia; but the flower when expanded is more like that of a Clarkia, from the long claws of the five petals, and the distance they are placed apart. Several of the species have their leaves and stems beset with stinging bristles, which adhere to the hands when touched. The fruit, which is eatable, but insipid, is a berry-like drupe, containing three one-seeded nuts. The species are natives of the West Indies, and they require a stove in England. The flowers are generally rose-coloured or purplish; but they are sometimes yellow. The common Barbadoes Cherry is called M. glabra, and its leaves are without stings. In Hiptage, another genus of this order, four of the petals of the flowers are white, and one yellow; and in Banisteria, the species are generally climbing shrubs, always with yellow flowers. Some of the species of Banisteria are occasionally found in stoves in this country, where their beautiful feathery yellow flowers have very much the appearance of those of the Canary bird flower (Tropæolum peregrinum).

ORDER XLIV.—ACERINEÆ.—THE MAPLE TRIBE.

Fig. 123.—Flower and Samara of the Sycamore. (Acer Pseudo-Platanus.)

The common Maple (Acer campestre) and the Sycamore (A. Pseudo-Platanus) are the only plants belonging to this order, that are natives of Britain; though so many kinds of ornamental Acers are now found in our parks and pleasure-grounds. Few trees are indeed more deserving of culture than the American Maples, both for their beauty in early spring, and for the rich shades of yellow and brown which their leaves assume in autumn. The Maple tribe is a very small one; it consists indeed of only the genera Acer and Negundo, and an obscure Nepal genus, of which there are no plants in Britain. Of all the Acers, one of the handsomest is the Sycamore tree (A. Pseudo-Platanus); the flower of this species (see e in fig. 123) is of a yellowish green; and as in early spring, when it appears, we are delighted at the sight of any thing in the way of flowers, it really looks very beautiful. Before I began to study botany, I had never noticed the blossoms of the forest trees, and when I was shown the light-feathery flowers of the Lime, and the gracefully-drooping ones of the Sycamore, I was quite astonished. The flowers of the Sycamore grow in a drooping raceme; the calyx is divided into five parts, but as it is scarcely distinguishable from the petals, which are five in number, and placed alternately with the sepals, it appears to be in ten divisions (see a). These flowers are partly male and female (see b and c), and partly perfect. In the perfect flowers there are eight stamens, and two stigmas; and the ovary when ripe expands into a curiously winged pod, called a samara (d), but differently shaped to the samara of the Ash, the thickened parts at the base of which contain the seeds. There is no albumen in the seed, which, when put into the ground, expands into two long thin cotyledons, (a in fig. 124) which, if once pointed out, will always be known again instantly. If a ripe seed be opened when quite fresh, the cotyledons or seed leaves will be found within it, fresh, green, and succulent; and these leaves (a in fig. 124), which rise above the ground as soon as the seed begins to germinate, differ widely in shape from the true leaves (b) which are serrated, and of a much thicker texture. The bracts of the Sycamore (f in fig. 123) are thick and leathery, and of a rich dark brown. The leaves are serrated at the margin; and the lower ones are cut into five lobes; but those near the flowers have generally only three lobes (e), and in all the leaves, two of the lobes are not so deeply cut as the others.

Fig. 124.—Young Sycamore.

There are many species of Acer, most of which are tall trees; and they are chiefly distinguished from each other by the shape of the leaves and of the samaras, or keys, the wings of which, in some species, are near together, as shown at d in fig. 123, and in others widely apart, as in the common hedge Maple (A. campestris), and in the Norway Maples, as shown at a in fig. 125. This figure represents the flowers of the Norway Maple (Acer platanoides), which are in what botanists call a corymb, and stand erect, instead of drooping like those of the sycamore. The leaves are deeply five-lobed, and the lobes are so coarsely toothed, that the teeth have almost the appearance of lobules. The buds of this plant in winter are large and red, and when they open in spring, the bracts (b) curl back over the scales (c). The leaves become of a clear yellowish red in autumn, and the whole plant is very ornamental. When a leaf of this tree is broken off, a milky sap issues from the broken petiole or leaf-stalk, which is of an acrid nature; differing in this respect, materially from the sap of the trunk, which is very sweet. Sugar indeed may be made from the sap of the trunk of almost all the Maples; but particularly in America, from that of the Sugar Maple (Acer saccharinum). The flowers of the red American Maple (Acer rubrum) are red, and as from their colour, and their appearing a fortnight before the leaves, they are very conspicuous, I have given a magnified representation of them in fig. 126, that my readers may have an opportunity of examining the male and female flowers from a living tree. In fig. 126, a a are male flowers, having no stigmas; and b b are female ones, having no stamens.

Fig. 125.—Flowers and Samara of the Norway Maple.

Fig. 126.—Flowers of the Red Maple (Acer rubrum).

The leaves of Acer rubrum become red in autumn. The Tatarian Maple differs from the other species in having entire leaves, and the samaras are red when young; but all the other kinds of Acer common in British gardens bear a strong family likeness to each other. The Ash-leaved Maple is now made into a separate genus, and is called Negundo fraxinifolia. This tree is easily distinguished from the Maples by its compound leaves, which resemble those of the Ash, and its long pea-green shoots, which have very few buds. The male and female flowers of the Negundo are on different trees, and they are so small as to be seldom seen, though the racemes of samaras or keys which succeed the flowers are very conspicuous. The Negundo is a native of America, and its leaves turn yellow in autumn.

ORDER XLV.—HIPPOCASTANEÆ, OR ÆSCULACEÆ. THE HORSE-CHESTNUT TRIBE.

Fig. 127.—Flowers of the Horse-chestnut.

Fig. 128.—Horse-chestnut.

This order contains only two genera; viz., Æsculus, the Horse-chestnut, and Pavia, the Buckeye; both of which are generally called Horse-chestnuts, though the genera are easily distinguished by their fruit, the husk of which is smooth in the Pavias, but rough in the true Horse-chestnuts. The buds of all the species of both genera are covered with bracted scales, most of which fall off when the leaves and flowers expand; and those of the common Horse-chestnut (Æsculus Hippocastanum) are very large, and covered with a kind of gum. Four large compound leaves, each consisting of five or seven leaflets, and a raceme of sixty-eight flowers, have Fig. 129.—Young plant of Horse-chestnut. been unfolded on dissecting one of these buds, before the leaves unfold in spring. The flowers of this species are produced in large, upright panicled racemes (see a in fig. 127); and the leaves (b) are compound, consisting of five or seven leaflets, disposed in a palmate manner. Two of the inner bracts, which remain after the outer scales (which are very numerous) have fallen, are shown at c. I mention this particularly, as these remaining bracts have very much the appearance of stipules, and it is one of the characters of the Horse-chestnuts that their leaves are without stipules. The flowers consist of five petals, two of which (d in fig. 128) are somewhat smaller than the others. Each petal consists of a broad blade or limb (e), and a very narrow claw (f). There are seven stamens, three of which (g) are shorter than the others. The filaments are inserted in the receptacle (h), and surround the pistil, which is hairy, and has a long style and a curved stigma (i). The ovary is two-celled, and each cell contains two ovules, but seldom more than one seed ripens. The nut (k) is large, and covered with a shining brown skin, which is strongly marked with the hilum. When put into the ground, the cotyledons do not appear in the shape of seed-leaves, but remain in the ground, and the plumule and radicle are protruded as shown in fig. 129. The Acorn germinates in a similar manner, as already shown in fig. 86 in p. 192.

The flowers of the different species of Æsculus Fig. 130.—Scarlet Horse-chestnut. Fig. 131.—Yellow Horse-chestnut. Fig. 132.—Nut of the Buckeye. vary considerably; as, for example, in the Scarlet Horse-chestnut (Æ. rubicunda), the calyx is tubular (see a in fig. 130), and there are but four petals, the upper two of which (b) are narrower than the lower ones (c), and have bearded claws. This species has sometimes eight stamens. In the Yellow Horse-chestnut, or yellow flowered American Buckeye, the upper petals (a in fig. 131) are very much smaller than the lower ones (b), and both have very long claws. There are four petals, which conceal the stamens, of which there are frequently only six. The seed of Pavia has only a small hilum, which resembles the pupil of an eye (see fig. 132); and hence the genus has received its American name of Buckeye. In one species (P. macrostachya), the nut is eatable, and very much resembles that of a Sweet Chestnut when boiled in milk. The stamens in this species are much longer than the petals, and they give a peculiarly light and elegant appearance to the flowers; which, unlike those of the other species, do not appear till the latter end of summer or autumn.