Order 2. Saxifragaceæ. The flowers are 4–5-merous with 2 (-3) carpels, most frequently: S5, P5, A5 + 5 (obdiplostemonous), G2. They are regular, ☿, polypetalous, hypogynous, perigynous or most frequently more or less epigynous (Fig. 488). The carpels may be individually quite free, but are more frequently united at the base, or the entire portion enclosing the ovules is united into a 1- or 2-locular ovary, the styles, however, are always free. Fruit a capsule with many seeds; endosperm present.—They are herbs, most frequently with scattered leaves without stipules; but the leaf-base is broad. The inflorescences are most frequently cymose, and a displacement of the floral-leaves is frequent (e.g. Chrysosplenium).—Some Saxifraga-species, e.g. S. sarmentosa, have irregular flower with an oblique plane of symmetry. The petal-stamens in some may be wanting: Heuchera, species of Saxifraga and Mitella. The corolla is wanting in others.

Saxifraga (Saxifrage): S5, P5, A5 + 5, G2 (Fig. 488); capsule bilocular, opening along the ventral suture between the 2 persistent styles. S. granulata has small tubers at the base of the stem.—Chrysosplenium (Golden Saxifrage): 4 sepals, no corolla, 4 + 4 stamens; 1-locular capsule.

The following genera are allied to the Saxifragaceæ:—

1. Parnassia (about 14 species; P. palustris, Grass of Parnassus). The flower is slightly perigynous, and has S5, P5, 5 fertile sepal-stamens, and 5 petal-stamens, which are developed as barren staminodes, palmately-lobed, and (3–) 4 carpels united in a 1-locular ovary with (3–) 4 parietal placentæ. Capsule.—Protandrous. The flower has a slightly oblique plane of symmetry, which is especially shown during its development and in the order of sequence in which the anthers dehisce: originally they lie closely round the gynœceum; the anthers dehisce extrorsely, first the one which is placed opposite the most external sepal (the 2/5 arrangement is very distinct in the calyx), the filament elongating so that the anther lies over the ovary, and this is followed successively by the 4 others in a zig-zag line; the filaments bend backwards after the pollen is shed and the anthers drop off, and the stigmas are not developed until this is completed. The barren stamens are palmately divided into an uneven number (7, 9, 11) of lobes, tapering from the centre towards the edge, and bearing apparently glandular tips; their gland-like appearance is supposed to allure flies to visit the flower, or they may act as a kind of fence which compels the insects to enter the flower in a certain way, and thus effect pollination; the honey is secreted on their inner side, and not by the gland-like tips.

2. Adoxa moschatellina (Moschatel). This is a perennial, creeping herb; the horizontal rhizome has an unlimited growth, and bears, in a scattered arrangement, both foliage-leaves, and white, fleshy scale-leaves. The aerial stem bears 2 opposite foliage-leaves and a capitate inflorescence of 5 flowers, 4 placed laterally (in opposite pairs) and 1 terminally. The flower is semi-epigynous, the calyx gamosepalous, corolla absent. The stamens are divided to the base, so that each filament bears a bilocular anther. The style is free, deeply cleft. The terminal flower has 2 bracteoles, 4 sepals, 4 stamens, cleft to the base, and a 4-locular ovary. The bracts of the lateral flowers are displaced on the flower-stalk, as in Chrysosplenium, and united with the 2 bracteoles into a kind of 3-leaved involucre; these flowers have 5 sepals, 5 split stamens with 2-locular anthers, and a 5-locular ovary. 1 pendulous ovule in each loculus. Fruit a drupe, green-coloured, with 1–5 stones.—This plant, which would perhaps be best placed in a special order, has also been classed with the Araliaceæ and Caprifoliaceæ.

Order 3. Ribesiaceæ (Currants). 5-stamened Saxifragaceæ with epigynous flowers.—Moderately sized shrubs with scattered, stalked and palminerved, and generally palmilobed leaves, with a large leaf-sheath. The flowers (Figs. 490, 491), most frequently borne in racemes, are regular, epigynous, and have often, above the ovary, a cup- or bell-shaped, or tubular prolongation of the receptacle, on which the sepals, petals and stamens are situated; they have 5 sepals (often large, coloured), 5 small, free petals, only 5 stamens (opposite the sepals) and a 2-carpellate gynœceum with a unilocular ovary and 2 parietal placentæ bearing many ovules. The fruit is a berry, whose seeds have a fleshy and juicy outer covering (Fig. 492). In some species, for example Ribes grossularia, there is found an unbranched, or a 3–5-branched spine, very closely resembling the spiny leaves of the Berberis, but which, however, are emergences springing from the base of the petiole. Ribes has two kinds of branches: long-branches and dwarf-branches, the latter alone bearing the flowers.—Ribes (Figs. 490–492). The blades of the leaf are folded or rolled together in vernation. R. alpinum is diœcious.

Family 20. Rosifloræ.

The leaves are scattered, stipulate, or have at least a well developed sheath, which is generally prolonged on each side into a free portion (“adnate stipules”). The flowers are regular, perigynous or epigynous. Calyx and corolla 5 (-4)-merous with the usual position. The corolla is always polypetalous. The stamens are present in very varying numbers (5–∞) and position, but always placed in 5-or 10-merous whorls; they are frequently 20 in 3 whorls (10 + 5 + 5; see Figs. 494, 502, 505); the nearer they are placed to the circumference, the longer they are; they are generally incurved in the bud, or even rolled up. The number of the carpels is from 1–∞; in most cases all are individually free (syncarp), and when they are united it is in every case with the ovaries only, whilst the styles remain more or less free (Pomaceæ, species of Spiræa). The seeds have a straight embryo, and usually no endosperm.

Order 1. Rosaceæ. Herbs or shrubs, generally with compound leaves and persistent (adnate) stipules, flower perigynous, gynœceum formed of many free (therefore oblique) carpels, syncarps with fruitlets of various kinds. The exceptions are noted under the genera.

1. Spiræeæ (Fig. 495) has 2–many ovules in each ovary, while in the other groups there is generally only 1, and never more than 2 ovules in each loculus. There are generally 5 cyclic carpels and the fruit is 5 follicles, which are not enclosed by the receptacle. The majority are shrubs. Stipules are often wanting.—Spiræa (Meadow-Sweet). The flowers are generally borne in richly flowered inflorescences of various forms. The carpels, in some species, unite together and form a simple gynœceum with free styles (an approach to the Pomaceæ).—Closely allied to Spiræa are the East Asiatic shrubs: Kerria japonica, which has solitary flowers, in this country nearly always double (the fruit a nut), and Rhodotypos kerrioides which has opposite leaves, a remarkable feature among the Rosifloræ; it has a 4-merous flower, a well developed disc inside the andrœcium, and a drupe. Closely allied also is Gillenia (N. Am.) differing chiefly in the ascending ovules, Spiræa having pendulous ovules, and a more tubular receptacle.

2. Potentilleæ (Figs. 494, 496, 497). The flower has an “epicalyx” (Fig. 494 C) alternating with the sepals and formed by their stipules which are united in pairs, and hence its leaves are often more or less deeply bifid. The receptacle is cupular and often quite insignificant. The sepals are valvate in the bud. The large number of fruitlets are achenes, borne on a well-developed convex portion of the receptacle (the Ranunculeæ resemble the Potentilleæ, but have no epicalyx, no enlarged receptacle, and spirally-placed stamens). Most of the species are herbs with dichasial inflorescences, often arranged in racemes.—Potentilla (Cinquefoil). The achenes are borne on a dry, hairy receptacle; the style is situated towards the apex of the ovary, and is not prolonged after flowering. Herbs with digitate, in some, however, pinnate leaves, and generally yellow flowers.—Comarum (Fig. 494) (Marsh Cinquefoil) forms, by its fleshy-spongy receptacle, a transition to the next genus.—Fragaria (Strawberry) (Fig. 496). The receptacle becomes finally fleshy, coloured, and falls off (biologically it is a berry); the numerous fruitlets (drupes with thin pericarp) have basal styles (Fig. 497); leaves trifoliate; long, creeping runners.—Geum (Avens) has a terminal style which after flowering elongates into a long beak, with the apex (after the uppermost part has been thrown off) bent back into a hook, thus furnishing a means of distribution for the fruits. Leaves pinnate.—Dryas comprises 3 Arctic or Alpine species with simple leaves and solitary flowers, the calyx and corolla 8–9-merous, the fruit resembles that of Geum, but the styles become still longer and feather-like (a flying apparatus).

3. Rubeæ. Rubus (Bramble) has the same form of receptacle as the Potentilleæ, but no epicalyx; the fruitlets are drupes, not enclosed by the persistent calyx. Most frequently shrubs or undershrubs with prickles (emergences), glandular bristles and compound leaves. In the Raspberry (R. idæus) the fruitlets unite together and detach themselves from the receptacle.

4. Roseæ. Rosa; the receptacle is hollow, ovoid and contracted beneath the insertion of the calyx (Fig. 498), ultimately fleshy and coloured; it encloses a large number of fruitlets which are achenes as hard as stones (“hip,” biologically a berry).—Shrubs with imparipinnate leaves and adnate stipules. The sepals show clearly the order of their development (a divergence of 2/5), the two outer ones on both sides are lobed, the third one on one side only, and the two last, whose edges are covered by the others, are not lobed at all. Prickles (emergences) are generally present and in some species are placed in regular order, being found immediately below each leaf (usually two) although at somewhat varying heights.

5. Agrimonieæ. The receptacle is more or less cup- or bell-shaped, and almost closed at the mouth; it is persistent and envelopes the nut-like fruitlets, but is dry, and in some species hard, the fruitlets being firmly attached to it. In biological connection with this the number of the carpels is generally only 1 or 2, and the whole becomes a false nut (Fig. 500). Herbs.—Agrimonia (Agrimony; Figs. 499, 500); the perianth is 5-merous, stamens 5–20. The receptacle bears externally, on the upper surface, a number of hooked bristles which serve as a means of distribution for the 1–2 achenes which are enclosed in it, and hence the entire flower finally falls off. The inflorescence is a long upright raceme. These bristles are arranged in whorls of 5 and 10, of which the uppermost alternate with the sepals.—Alchemilla (Ladies-mantle; Fig. 501) has 8 green perianth-leaves in two whorls (some authorities consider the four outer as an epicalyx, and the flower therefore apetalous), and 4 stamens alternating with the innermost whorl. There is only one carpel with a basal style and capitate stigma. The flowers are small and greenish, the filaments jointed. The anthers open by one extrorse cleft. The leaf-sheath entirely envelops the stem; the leaves are palminerved. A. aphanes has often only 1–2 stamens. The following genera, with 4-merous flowers borne in short spikes or capitula, are allied to this group. Sanguisorba has entomophilous, ☿-flowers with 4(-20) stamens, 1 carpel; stigma papillose.—Poterium; spike or capitulum, the uppermost flowers are ♀, the lowermost ♂, and some intermediate ones ☿ (the order of opening is not always centripetal); S4, P0, A20–30, G2, the long styles having brush-like stigmas (wind-pollination). Leaves imparipinnate.

Order 2. Amygdalaceæ. Trees or shrubs with rosaceous flowers; leaves simple with caducous stipules; a regular, perigynous flower, the receptacle being partly thrown off by a circular slit; sepals 5, petals 5, stamens 20–30; gynœceum simple, formed of 1 carpel (hence oblique, Fig. 502), with terminal style and 2 pendulous ovules, ripening into a drupe (Fig. 503).—The leaves are penninerved and frequently have glands on the stalks and edges; thorns (modified branches) often occur, i.e. dwarf-branches, which, after producing a few leaves, terminate their growth in a thorn (e.g. Prunus spinosa). The vernation of the foliage-leaves varies in the different genera; in the Almond, Peach, Cherry, and Bird-Cherry they are folded; in the Apricot, Plum, Sloe and Bullace, rolled together. In some the flowers unfold before the leaves (Amygdalus, Armeniaca). That the gynœceum is formed of 1 carpel is evident in this as in other instances (e.g. in the Leguminosæ, which are closely related to this order), from the fact that the carpel is oblique, and has only one plane of symmetry, and similarly in the fruit there is a longitudinal groove on one side which indicates the ventral suture. It is only exceptionally that both ovules are developed. In abnormal instances more than 1 carpel is developed.

A. Fruit hairy: Amygdalus (A. communis, Almond-tree) has a dry pulp which is detached irregularly, when ripe, from the wrinkled, grooved, ovoid and somewhat compressed stone.—Persica (P. vulgaris, Peach-tree) differs from the Almond in having a juicy pulp, not detachable from the stone, which is deeply grooved and has pits in the grooves (Fig. 503). (The name of the genus is derived from Persia, though it is a native of China.).—Armeniaca (A. vulgaris, Apricot) has a hairy, velvety fruit, but the stone is smooth and has two ribs along one of the edges; the pulp is juicy. (The generic name has been given on the incorrect assumption that it was a native of Armenia; its home is China.)

B. Fruit glabrous (i.e. without hairs): Prunus (Plum) has a glabrous fruit with bluish bloom; the stone is compressed, smooth or wrinkled. The flowers are borne solitarily or in couples, and open before or at the same time as the leaves; they are borne on shoots without foliage-leaves.—Cerasus (Cherry) has a glabrous, spherical fruit, without bloom, and a spherical stone. The flowers are situated in 2–many-flowered umbels or racemes, and open at the same time as the leaves or a little before them. Long-stalked flowers in umbels are found in C. avium (Wild Cherry), C. vulgaris (the cultivated Cherry, from Western Asia); racemes at the apex of leaf-bearing branches and small spherical fruits are found in C. padus (Bird Cherry), C. virginiana, C. laurocerasus (Cherry-laurel), C. mahaleb.

Order 4. Pomaceæ. Trees and shrubs, most frequently with simple leaves and caducous stipules. The flowers (Fig. 505) have 5 sepals, 5 petals and generally 20 stamens (10 + 5 + 5, or 10 + 10 + 5). There are from 1–5 carpels, which unite entirely or to some extent with each other, and with the hollow, fleshy receptacle (the flower becoming epigynous), (Figs. 505, 506, 507). The carpels are nearly always free on the ventral sutures, rarely free at the sides also. The whole outer portion of the fruit becomes fleshy, but the portions of the pericarp surrounding the loculi (endocarp) are most frequently formed of sclerenchymatous cells, and are more or less firm (the “core”). The nature of the fruit varies, according to the thickness and hardness of the endocarp, being either a “berry” or a “drupe” (see A and B). When the endocarp is thin and parchment-like, the fruit has the characteristics of a berry, each of the 5 loculi generally present containing several seeds; but when this is hard the fruit resembles a drupe, only one seed is developed in each loculus, and the number of the loculi is reduced to one or two. There are nearly always 2 ovules in the loculi of the ovary, but in Cydonia there are a large number in 2 rows. In the genera which have stones, only one seed is developed in each stone. The genera are distinguished mainly in accordance with the kind of fruit and the number of ovules and seeds.

A. Sorbeæ. The endocarp is parchment-like or papery (drupe, with thin stone or berry).

1. Pyrus and Cydonia; carpels completely embedded in the cup-like receptacle, styles always free.—Pyrus: the fruit is glabrous, and has only a small calyx, withering or deciduous, and a 5-locular ovary with at most 2 ascending ovules in each loculus (Fig. 504 D). The large flowers are situated in few-flowered umbels or corymbs. P. communis (Pear; free styles, Fig. 507; it has the well-known pear-shaped fruit; the core is reduced to several groups of sclerenchymatous cells embedded in the pulp, the leaf-stalk is as long as the blade).—Cydonia (Quince) has a hairy fruit with many seeds in 2 rows in each loculus of the endocarp (Figs. 504 C, F; 506); the testa of these seeds is mucilaginous. C. vulgaris, large, terminal flowers on lateral branches, and large leaf-like, persistent sepals.

2. Malus and Amelanchier (Aronia); carpels free on the ventral edge; styles united. Malus communis (Apple) the fruit is “umbilicate” at the base; no sclerenchymatous cells in the pulp; styles united at the base (Fig. 504 D); leaf-stalk shorter than the blade. Sorbus (Mountain-ash) differs only in having a 2–3-locular fruit with extremely thin endocarp. Cymose inflorescences in umbellate cymes. S. aucuparia has pinnate leaves, S. aria (White-beam) and other species have simple leaves.—Amelanchier (the Service-tree) has a false divisional wall springing from the dorsal suture, and more or less projecting into each of the loculi of the ovary; Raphiolepis (Fig. 504 E) has racemes and a juicy berry; Eriobotrya japonica (Loquat).

B. Cratægeæ. The endocarp is hard and bony (“drupes,” generally with several, sometimes, however, with only 1–2 stones, rarely one multilocular stone; only 1 seed in each of the loculi).—Cratægus (Hawthorn, May). There are 1–5 stones in the spherical or ovoid fruit. The disc, found on the apex of the fruit, inside the small, withered calyx, is small (much less than the transverse section of the fruit). Shrubs with thorns (branches) and moderately large flowers borne in corymbs.—Mespilus (Medlar) differs from the last-named only in having a large disc at the apex of the fruit, inside the large, leaf-like sepals, i.e. almost equal to the greatest diameter of the fruit. The flowers are solitary and terminal.—Cotoneaster is chiefly distinguished from the others by its syncarps, the 2–5 carpels (and stones) being free from one another, and only united to the receptacle by a larger or smaller portion of their dorsal surface (Figs. 504 A, B). Small shrubs with leathery leaves, generally covered with white, felted hairs on the lower surface, and with small flowers; the fruit is red or black.

Family 21. Leguminosæ.

The most characteristic feature is, that the gynœceum is 1-locular and formed of 1 carpel, the ventral suture of which is turned posteriorly. The fruit, in most instances, is a pod (legume), which opens generally along both sutures, the two valves twisting more or less in opposite directions. In other instances it opens along one suture only, or as a pyxidium (Red Clover), or it is indehiscent, in which case it is more or less berry-like (e.g. the Tamarind, Carob-bean), or it is a drupe (e.g. the Tonquin-bean), or a 1–few-seeded nut (e.g. Melilotus), or a lomentum, which divides transversely into as many joints as there are seeds (Ornithopus, see Fig. 513).

The inflorescences belong to the centripetal type (i.e. indefinite); cymes do not occur. The flowers are zygomorphic, with vertical plane of symmetry, seldom regular; 5-merous with but a few exceptions, ☿, and slightly perigynous. The following diagram is the most general (Fig. 511): 5 sepals, with the unpaired sepal median and anterior, 5 petals, 5 + 5 stamens, all in alternating whorls, 1 carpel. The calyx is most frequently gamosepalous, the gynœceum is narrowed down at the base to a short stalk and, in the majority, is more or less bent. The seed is most frequently kidney-shaped, with a smooth, hard and shining testa, the hilum being very distinct. Endosperm is wanting, or is reduced to a thin layer, which is of service when the seed swells during germination. The vegetative parts have these features in common, namely, the leaves are scattered, stipulate, and almost always compound. Peculiar sleep-movements and sensitiveness are found in some, chiefly in the Mimosas. Many, probably all, Leguminosæ have small tubercles on their roots which are produced by a kind of bacterium, and assist in the assimilation of free nitrogen. Spontaneous movements are exhibited by Desmodium gyrans (Telegraph-plant).

Order 1. Cæsalpiniaceæ. These are leguminous plants with straight embryo and a flower which is not papilionaceous and has not the same æstivation (Figs. 508–510); but in reality there is not a single characteristic which absolutely distinguishes them from the Papilionaceæ.—The majority are arborescent; the leaves as a rule are pinnate or bipinnate. The flower is 5-merous, most frequently perigynous and slightly zygomorphic; the calyx is free or gamosepalous, the corolla polypetalous with ascending imbricate æstivation (i.e. the two lowest petals envelop the lateral ones, and these again the posterior; Fig. 508); 10 free stamens; fruit various.