A. Fruit a capsule. Œnothera (Evening Primrose) is 4-merous, has 8 stamens, a tubular receptacle, and an oblong capsule with loculicidal dehiscence leaving a centrally placed column, bearing the seeds.—Epilobium (Willow-herb) deviates from Œnothera especially in the seeds being hairy (at the chalazal end of the seed).—Chamænerium is a Willow-herb with zygomorphic flowers.—The following may be included here: Clarkia, Eucharidium (an Œnothera with 4 stamens and 3-lobed petals), Godetia and Boisduvalia, Jussiæa (dehiscence septicidal), Isnardia (petal-stamens absent, sometimes the petals also).—Lopezia has a peculiar, zygomorphic flower (Fig. 521); one of the four sepals is bent forwards and the other 3 backwards; the posterior petals are narrower than the 2 anterior ones which are turned obliquely backwards and bent like a knee, with a greenish nectary at the bend; 2 stamens, one only fertile (the posterior), while the anterior is barren, petaloid, and spoon-shaped; both are sensitive, which is essential for pollination. In Fig. 521, a represents an early stage, in which the stamen and style lie concealed in the staminode; b is the ♂ stage, the stamen projects from the centre of the flower; c, the ♀ stage, the style occupies the place of the stamen.

B. Fruit a berry. Fuchsia generally has a coloured calyx and tubular receptacle; the corolla may be wanting.

C. Fruit a nut. Circæa (Enchanter’s Nightshade) has a 2-merous flower (S2, P2, A2 + 0 [petal-stamens are wanting], G2). The flowers are borne in racemes without bracts.—Gaura.

D. Fruit a drupe. Trapa (Horn-nut); a peculiar aquatic plant; the submerged stem has long internodes and lanceolate leaves, falling off at an early period, but at each node are found 4 long roots with thin, lateral roots (sometimes erroneously regarded as leaves) borne pinnately; the stem reaching the surface of the water, bears a rosette of rhombic foliage-leaves, with large, inflated stalks containing air, and forming the floating apparatus of the plants. In the axils of the leaves (as in Gunnera) 8 small, stipular structures are present. The flowers are solitary in the axils of the foliage-leaves (S4, P4, A4 + 0, G2), semi-epigynous. There is an 8-lobed, crenate disc on the free portion of the ovary; one ovule in each loculus. The fruit is a drupe with 4 (or 2) prominent horns (the persistent sepals), which after the pulp has decayed away bear a series of hooks turned downwards on each side, i.e. sclerenchymatous bundles which formerly lay concealed in the pulp of the sepals. The germination is peculiar: one of the cotyledons is large, and its thick extremity remains in the fruit, the other however is small and is pushed out at the apex of the fruit together with the radicle and plumule; the development of the root soon ceases, and the plumule usually grows into a stem entirely without branches, similar to the one described above, only that 1–2 precisely similar shoots arise in the axil of each cotyledon, so that each embryo produces 3–5 shoots.—Trapa, by its mode of life, its 1-seeded fruit, etc., forms a transition to Haloragidaceæ.

Order 5. Haloragidaceæ. This is a reduced form of the Œnotheraceæ, and principally differs from these in the presence of endosperm and free styles. Only 1 ovule in each loculus.—84 species distributed over the entire globe; the majority are aquatic plants. The most advanced type is Myriophyllum (Water-Milfoil), with a regular, epigynous flower (S4, P4, A4 + 4, G4), most frequently diclinous (monœcious); the fruit is a 2–4-partite schizocarp. Aquatic plants, most frequently with pectinate, pinnate leaves.—Haloragis.—Gunnera (a dozen species from the Southern Hemisphere) forms the next step in the reduction. Large, scattered, rough-haired, and softly-spined leaves, with small flowers in crowded inflorescences. The flower, when most complete, has S2, P2, A2 (petal-stamens) and G2, forming an inferior, unilocular ovary with 1 ovule. It is remarkable for the great number of stipules placed in transverse rows in the leaf-axils, for the peculiar glandular organs, and for the colonies of Nostoc, which are found embedded in the cortex as a kind of parasite.—The simplest form is Hippuris (Mare’s-tail) with an extremely small, crenate or entire calyx, without corolla, and with only one stamen and one carpel, forming an inferior, unilocular ovary with only one ovule. Fruit a drupe with thin pulp. It is an aquatic plant with creeping, sympodial rhizome, and erect unbranched shoots, bearing numerous small, verticillate leaves. The small flowers are situated singly in the leaf-axils.

Order 8. Myrtaceæ (Myrtles). The plants belonging to this order are shrubs or trees, the majority being easily recognised by the vegetative characters. The leaves, for instance, are most frequently opposite, without stipules, undivided and entire, parchment-like or leathery, evergreen, aromatic, finely dotted by pellucid glands containing essential oils; the venation is penninerved with a nerve just inside and running parallel to the edge of the leaf. The flowers are regular, epigynous (Figs. 523, 524, 525) and ☿, most frequently 4- or 5-merous in the calyx and corolla, with many stamens (by splitting, so that they are often in several distinct bundles) and an ovary with one style, formed of 2–5–many carpels; the receptacle is most frequently united for its entire length with the ovary. The fruit varies, but is most frequently a berry. The embryo is thick, often curved, with united cotyledons; no endosperm.

1. Myrteæ, Myrtle Group. Chiefly American, though some are found also in Africa and Asia. The fruit is a berry with generally 2–5 loculi in the ovary, and many ovules in each.—Myrtus; Eugenia (the petals fall off together as a hood in the Clove, E. caryophyllata, Figs. 523, 524); Myrcia; Jambosa; Amomis; Psidium, etc.

2. Puniceæ, Pomegranate Group. Only 2 species (Punica granatum; from Persia, Afghanistan), differing in several respects from the typical form of the Myrtaceæ. The leaves are generally opposite, without glands and marginal veins. The receptacle, calyx and corolla are red; the latter 5–8–(generally 6-) merous. Calyx valvate and corolla folded as in Lythraceæ, stamens also and epicalyx as in this order. The most characteristic feature is the inferior, spherical berry, with dry pericarp, formed from two whorls of carpels in two tiers (Fig. 525); the interior whorl, which is also the lower, has 3 carpels, and the placentæ are situated in the inner angles of the 3 loculi; the external whorl is 5-merous, and the placentæ have originally the same position in the inner angles of the loculi, but their position is changed to the outer side of the loculi owing to the growth of the wall of the ovary, which takes place early, causing the carpels to become, as it were, turned inside out, so that the part which was turned downwards is turned upwards, and the part which was turned inwards becomes turned outwards (as in Mesembrianthemum). The edible part of the fruit is the fleshy testa, as in Ribes. The cotyledons are rolled together spirally.

Family 24. Umbellifloræ.

The flower is regular, ☿, and completely epigynous, 5- or 4-merous, with 1 whorl of stamens and 5–2 carpels. Sepals very small, tooth-like. The corolla is polypetalous, most frequently valvate in æstivation (least pronounced in the Umbelliferous plants). Round the base of the styles, which are generally free, there is an epigynous (undivided, or divided) nectar-disc (“stylar-foot”: Figs. 528 B, C, D; 539); the number of loculi in the ovary equals that of the carpels; only 1 pendulous (anatropous) ovule (Fig. 528 C) in each loculus. Endosperm copious (Fig. 528 D). To this must be added that the inflorescence in the majority of cases is an umbel or a capitulum, especially in the Umbelliferæ and Araliaceæ. Stipules are absent, but most frequently the base of the petiole forms a large sheath.

Order 1. Cornaceæ. The majority of the species are shrubs with solid internodes, opposite (rarely scattered) leaves, which are simple, entire (rarely incised), penninerved, without stipules or large sheaths; flowers 4-merous (most frequently S4, P4, A4, G2), borne in dichasia which are either collected into corymbs (e.g. Cornus sanguinea), or in closely crowded umbels or capitula (Cornus mas, C. suecica), in which latter case there is often a large, leafy, or coloured, most frequently 4-leaved involucre round the base of the inflorescence; the style is undivided, with lobed stigma; the raphe of the ovule is turned outwards. The fruit is a berry or a drupe, with a 1–4-locular stone or 2 free stones.

Cornus (Dogwood, Cornel) has S4, P4, A4, G2. Leaves opposite.

Drupe with a bilocular, 2-seeded stone.—Aucuba, diœcious; unilocular ovary; 1 ovule; 1-seeded berry.—Garrya.—Helwingia.

Order 2. Araliaceæ (Ivies). Principally trees or shrubs with solid stems. The leaves are scattered, simple or compound, with a sheath more or less developed. The flowers are most frequently situated in umbels or capitula which are either borne singly or in racemes, or in paniculate inflorescences. The small, most frequently yellowish-green flowers are 5-merous, in the calyx, corolla, and andrœcium; the gynœceum may be 5-merous or may have some other number (2-∞). The styles are most frequently several, free; the raphe of the ovules is turned inwards as in the Umbelliferous plants. The fruit is a drupe or berry.—Stellate hairs often occur. The petals generally have a broad base, and a thick apex which is slightly incurved, and a distinctly valvate æstivation.

Hedera helix (Ivy) climbs by adventitious roots. The leaves are palminerved and lobed on the sterile branches, but often ovate and not lobed on the flowering branches. The flowers are yellowish-green and open in the autumn; they are slightly protandrous, and are visited by flies and wasps. Berries black. Endosperm ruminate.—Panax. Aralia (with Dimorphanthus).

Order 3. Umbelliferæ. The stem is herbaceous with hollow internodes; the leaves are scattered, and have a broad, amplexicaul base, a large, most frequently inflated sheath, and generally a pinnate (often very much dissected) blade. Entire leaves are found in Hydrocotyle vulgaris; Bupleurum.

The flowers are ☿, regular, small, but collected in compound umbels, that is, in “simple umbels,” which again are borne in umbels (for exceptions see Hydrocotyleæ); the external flowers in the simple umbel have often subtending bracts, which surround the base as an involucre, and may be termed the small involucre; the internal ones have no bracts; when involucral leaves are present at the base of the compound umbel, they may be termed the large involucre.

The flower has 5 sepals (the median, as usual, posterior), 5 petals, 5 stamens and 2 carpels (in the median line) (Fig. 528). The calyx is often scarcely indicated. The petals have a short claw are most frequently obcordate, or have an incurved apex (Fig. 528 B, C), being incurved in the bud; they are white, rarely yellow (Fennel and Parsnips), blue or red. The flowers are sometimes zygomorphic, especially those on the circumference of the umbel, and in that case it is the petal which is directed outside (anterior) which is the largest, and the two posterior are the smallest (e.g. Heracleum). The stamens are incurved in the bud. The 2 free styles unite at the base into the “stylar-foot” (stylopod), a swollen nectary (Fig. 528 B, C); the ovary is bilocular, the raphe of the ovules being directed inwards. The fruit is a schizocarp, dividing into two mericarps; the plane in which these separate coincides with that of the union of the carpels, and the two nut-like mericarps are in most genera kept together for awhile at the top of a thin, bifid, or undivided stalk (carpophore) which is in direct continuation with the flower-stalk (Fig. 537). Each mericarp has most frequently 5 more or less strongly projecting ridges, the primary ridges (Figs. 530, 532, 534, 535, etc.), of which 3 lie on the back of the mericarp, the dorsal ridges, and 2 on its edge near the plane of division, the marginal ridges; five of these (10 ridges in all in the entire fruit) are placed opposite the calyx-teeth and the others between them. In some genera there are in addition 4 secondary ridges to each mericarp between the primary ones (Fig. 528 E: the secondary ridges bear the long bristles). Inside these secondary ridges, or inside the grooves between the primary ridges, when the secondary ridges are absent, oil ducts (vittæ, schizogenous ducts) are found in the pericarp, most frequently one in each groove; two are also often found on the ventral side of each mericarp (Figs. 528 E, 530 ol, etc.). The seed is most frequently united with the pericarp. The embryo is small and lies high up in the large, most frequently horny endosperm (Fig. 528 D).—The endosperm does not contain starch, but oil, and presents three different forms, of important systematic value: (a) those which are quite flat on the ventral side (i.e. the side turned towards the plane of splitting) (Figs. 528 E, 530, 531, 534, etc.): the majority of the genera, Orthospermeæ (e.g. Carum, Pastinaca); (b) those in which the endosperm on the ventral side is provided with a longitudinal groove, often deep: Campylospermeæ (e.g. Anthriscus); the transverse section is nearly a crescent (Fig. 532); (c) those in which the endosperm is concave on the ventral side (hollow in both longitudinal and transverse sections): Cœlospermeæ (e.g. Coriandrum) (Fig. 538).

1. Hydrocotyleæ, Penny-wort Group. Capitula or simple umbels (all the other groups have compound umbels). No oil-ducts. Orthospermous.—Hydrocotyle (Penny-wort). The fruit is considerably compressed laterally (Fig. 529). The calyx-teeth are small. The leaves are peltate.—Didiscus.—Sanicula (Sannicle). The umbels are small, capitate, generally collected in a raceme; calyx-teeth distinct. ♂-and ♀-flowers in the same umbel. The fruits are round, studded with hooked bristles. No carpophore.—Astrantia has an umbel surrounded by a large, often coloured involucre, with this exception it is the same as the preceding, but the fruit is slightly compressed, with 5 equal ridges. Hacquetia (Dondia).—Eryngium (Sea Holly): leaves often thorny. The flowers are all sessile, the inflorescence is thus a capitulum; each flower is often subtended by a bract, which is thorny like the involucre, resembling the burrs of the Teasel. The sepals are large.—Lagœcia: one of the loculi of the ovary is suppressed.

2. Ammieæ, Caraway Group (Figs. 530–532). The fruit has only the 10 primary ridges; it is usually short, almost spherical or broadly ovate and distinctly compressed laterally. Oil-canals are most frequently present. Orthospermous (except Conium).—Cicuta (Cow-bane). Pointed calyx-teeth. Glabrous herbs with pinnate or bipinnate leaves. C. virosa has a thick, vertical rhizome, divided by transverse septa into many compartments; the leaflets are narrow, lanceolate, and dentate; the large involucre is wanting.—Apium (Celery). No calyx-teeth. A. graveolens, a maritime plant, has neither large nor small involucre; the umbels are short-stalked or sessile.—Carum (Caraway). Calyx-teeth small; the large involucre is wanting or is only few-leaved. C. carvi (Caraway). C. petroselinum, (Parsley) (Fig. 530). Falcaria; Ammi; Helosciadium; Bupleurum (Hare’s-ear) with simple leaves and yellow corolla; Pimpinella (Fig. 531); Sium; Ægopodium (A. podagraria, Gout-weed) has bi- or tri-ternate leaves, with ovate, dentate leaflets; the large involucre is wanting.—Conium is campylospermous (Fig. 532); the short, broadly ovate fruit has distinctly projecting, often wavy crenulate ridges. C. maculatum (Hemlock) has a round, smooth stem with purplish spots.

3. Scandiceæ. This group has a distinctly oblong or linear fruit which is slightly compressed laterally, and generally prolonged upwards into a “beak”; wings absent. Campylospermous. Otherwise as in the Ammieæ.—Anthriscus (Beaked Parsley) has a lanceolate fruit, round on the dorsal side, without ridges, but with a ten-ridged beak.—Scandix (Shepherd’s-needle).—Chærophyllum (Chervil): fruit lanceolate or linear with low, blunt ridges; beak absent or very short. C. temulum has a red-spotted, hairy stem.—Myrrhis (Cicely) has a short beak and sharp, almost winged ridges. M. odorata (Sweet Cicely) has very long fruits.

4. Seselineæ, Fennel Group (Figs. 533, 534). The fruit is slightly elliptical or oblong, in transverse section circular or nearly so, without grooves in the dividing plane; only primary ridges are present. Orthospermous.—Fœniculum (Fennel) has yellow petals; both involucres are wanting; the fruit is oblong. The ridges are thick, all equally developed, or the lateral ridges are slightly larger (Fig. 534).—Æthusa (A. cynapium, Fool’s Parsley); the large involucre is wanting or is reduced to one leaf, the small involucre is composed of three linear leaves which hang downwards on the outer side of the umbels. The fruit is spherical-ovate, with thick, sharp, keeled ridges, the lateral ones of which are the broadest.—Œnanthe (Dropwort); the fruit (Fig. 533) has usually an ovate, lanceolate form, with distinct, pointed sepals and long, erect styles; the ridges are very blunt, the marginal ones a trifle broader than the others.—Seseli, Libanotis, Cnidium, Silex, Silaus, Meum, etc.

5. Peucedaneæ, Parsnip Group (Figs. 535–537). The fruit is most frequently very strongly compressed dorsally, with broad, mostly winged, lateral ridges. Only primary ridges. The dorsal ridges may project considerably, but are not winged. Orthospermous.

a. The winged lateral ridges stand out from each other, so that the fruit appears to be 4-winged (Fig. 535).—Angelica; Archangelica (Fig. 535); Levisticum (Lovage).

b. The winged lateral ridges lie close together, and form one wing on each side of the fruit (Fig. 536).—Pastinaca (Parsnip). Corolla yellow. The dorsal ridges are very weak; the oil-ducts do not reach quite as far as the base of the fruit. Both large and small involucres are wanting; leaflets ovate. Anethum (Dill) is a Parsnip with more distinct dorsal ridges and filamentous leaflets. Peucedanum (Hog’s-fennel); Ferula (with Scorodosma, Fig. 536, and Narthex); Dorema.—Heracleum (Cow-parsnip); the flowers in the margin of the umbels are often very large, zygomorphic, and project like rays, e.g. in H. sibiricum. The fruit is very flat, with very small dorsal ridges; the oil-ducts are more or less club-like and do not reach as far as the base of the fruit (Fig. 537). Imperatoria; Tordylium.

6. Dauceæ, Carrot Group (Fig. 528). The fruit has 18 ridges, i.e. each fruitlet has 5 primary and 4 secondary ridges, the latter being often more prominent and projecting further than the primary ones. The oil-ducts are situated under the secondary ridges (Fig. 528).

a. Orthospermous: Daucus (Carrot). The secondary ridges project much further than the primary, and bear on their crests a series of hooked spines (Fig. 528 D, E); these are much longer than the small bristles on the primary ridges. The involucral leaves of D. carota (Carrot) are numerous and deeply pinnate; the inflorescence contracts during the ripening of the fruit, and since the external umbels have longer stalks than the central ones, they arch over them, and the inflorescence becomes hollow. For the terminal flower, see below.—Cuminum; Laserpitium; Melanoselinum.

b. Campylospermous: Torilis (Hedge Parsley). The primary ridges are covered with bristles; the secondary ridges are not. very distinct on account of the spines, which entirely fill up the grooves. Caucalis (Bur Parsley).

c. Cœlospermous: Coriandrum (Coriander) has a smooth, spherical fruit (Fig. 538) with a distinct, 5-dentate calyx, the two anterior (i.e. turned outward) teeth being generally longer than the others; the two fruitlets scarcely separate from each other naturally; all the ridges project only very slightly, the curved primary ones least, the secondary ridges most.

Family 25. Hysterophyta.

This family (with the exception of Aristolochiaceæ) includes only parasitic plants. Partly on this ground, and partly because they all have epigynous flowers, they are considered to belong to the youngest type (which is expressed in the name ὕστερος, the one that comes after). It is not certain to which of the preceding families they are most nearly allied. Again, it is a matter of doubt whether the Aristolochiaceæ are related to the others; they are by Engler united with Rafflesiaceæ into one family, Aristolochiales.

Order 1. Aristolochiaceæ. The majority are perennial herbs or twining shrubs, whose stalked, simple, and generally more or less cordate or reniform leaves are borne in 2 rows and are exstipulate. The flowers are hermaphrodite, epigynous, regular or zygomorphic; perianth-leaves united, simple but most frequently petaloid and 3-merous; 6 or 12 (in Thottea as many as 36) stamens with extrorse anthers. The ovary is more or less completely 4–6-locular with ovules attached in the inner angles of the loculi (Fig. 540 kf). The style is short, and has a large, radiating stigma (Fig. 540 n). Fruit a capsule. Seeds rich in endosperm.

Asarum europæum. Each shoot has 2 reniform foliage-leaves, between which the terminal flower is borne (the rhizome becomes a sympodium by development of the bud in the axil of the upper foliage-leaf). The flower is regular and has a bell-shaped perianth with 3 outer valvate, and 3 inner small segments (which may be wanting). 12 (2 × 6) free, extrorse stamens, 6 carpels.—Aristolochia clematitis (Birth-wort) has an erect, unbranched stem, bearing many flowers in the leaf-axils, in a zig-zag row (accessory buds in a unipared scorpioid cyme). The flowers are zygomorphic (Fig. 540), formed by 3 alternating, 6-merous whorls. The perianth has a lower, much-distended part (k), succeeded by a narrow, bent tube (r), which passes over into an oblique, almost tongue-like projection (6 vascular bundles indicate that the number 6 is prevalent here, as in Asarum); 6 stamens (Fig. 540 a), with the dorsal portion turned upwards, are united with the short style to form a stylar column; they are placed quite beneath the 6 commissural stigmatic rays, which arch over them as short, thick lobes. Protogynous; Pollination is effected in Arist. clematitis by small flies; these enter the erect unfertilised flower through the tube (Fig. 540 A, l) without being prevented by the stiff, downwardly-turned hairs which line the tube and prevent their escape; they find the stigma (n) fully developed, and may pollinate it with the pollen they have brought with them. The stigmas then straighten and wither (B, n), the anthers open, and the flies may again be covered with pollen; but the hairs which blocked up the tube do not wither until the anthers have shed their pollen, and only then allow the imprisoned flies to escape and effect cross-pollination. Prior to pollination, the flowers stand erect, but after this has taken place they become pendulous, and the perianth soon withers.—A. sipho (Pipe-flower), another species, is a climber, and often grown in gardens; it has only one row of accessory buds in the leaf-axils.—200 species; chiefly in S. Am. Officinal: the rhizome of Aristolochia serpentaria (N. Am.).