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 frequently 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.

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 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. 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.

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, become 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.

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.

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.

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