Order 5. Oleaceæ. The leaves are always opposite. The inflorescences are racemes or panicles. The calyx and corolla are 4-merous, more or less united, free in some species; the corolla has most frequently valvate æstivation. All four forms of fruit occur (see the genera). Ovules pendulous, 2 in each loculus (Fig. [583] C). Endosperm oily.—Syringa (Lilac) and Forsythia (anthers somewhat extrose) have capsules with loculicidal dehiscence and winged seeds.—Fraxinus (Ash) has winged nuts (samara) (Fig. [583] D); trees with most frequently imparipinnate leaves; the flowers are naked and sometimes unisexual (polygamous), the Manna Ash (F. ornus) has however a double perianth with 4 free petals (Fig. [583] a); in the native species, F. excelsior, the flowers open before the foliage appears.—Ligustrum (Privet) has berries.—Olea (O. europæa; Olive) has drupes; the pulp and seeds of the ellipsoidal fruits are rich in oil. The lanceolate leaves are grey on the under surface, being covered with stellate hairs. In the wild state it is thorny (modified branches).—Phillyrea; Chionanthus.—Few species of Linociera have 4 stamens.
Fig. 583.—Fraxinus ornus: A flower; ca calyx; co corolla; B gynœceum and calyx; C longitudinal median section of gynœceum; D fruit.
180 species; chiefly in the northern temperate zone. The Olive-tree (Olea europæa) has been an important cultivated plant from ancient times (Olive oil, Provence oil, “Sweet oil”). The best oil is extracted from the fruit-pulp. The fruits are edible. Home: Western Asia, Eastern Mediterranean. Timber: the Ash (Fr. excelsior). Officinal: the Manna Ash (Fr. ornus), cultivated in the Mediterranean countries for the sake of its saccharine juice, which flows out and coagulates into “Manna.”—The following are ornamental plants: species of Ligustrum and Syringa (introduced in the 16th century, from S.E. Europe and Asia), Forsythia (China, Japan; the large, yellow flowers are borne on dwarf-branches with scale-like leaves, before the opening of the foliage-leaves), Chionanthus.
Order 6. Jasminaceæ. The æstivation of the corolla is imbricate; the ovules are erect; seeds almost without endosperm; radicle directed downwards. The number of lobes in the calyx and corolla is not 4, but e.g. 5, 8, 10, and variations are sometimes found in the same individual. The fruit is a berry or capsule. Many species are twiners, and their scattered or opposite leaves are most frequently imparipinnate.—120 species; especially in Trop. Asia (E. India). Some Jasminum-species are cultivated as ornamental shrubs in the warmer districts on account of their elegant foliage, and beautiful, sweet-scented flowers, the essential oil of which is also used in perfumery; the best known are: J. sambac and grandiflorum. Nyctanthes arbor-tristis opens its sweet-scented flowers only at night (E. India).
Order 7 (?). Salvadoraceæ. 8–9 species; Asia, Africa.—Salvadora.
b. Tetracyclicæ with epigynous flowers.
Family 33. Rubiales.
The leaves are always opposite or verticillate. The flower is epigynous, ☿, 5-(or 4-) merous, with the usual sympetalous diagram; 2–5 carpels. The inflorescences are frequently dichasial. The sepals are small, reduced to teeth, and become almost entirely suppressed in the higher forms.—The flower is regular in Rubiaceæ and some Caprifoliaceæ, but in other genera of this latter order (especially of Lonicereæ) it is unsymmetrical. In several genera of the order first mentioned the loculi of the ovary contain many ovules, but in the last the number of loculi and ovules becomes reduced. This is to some extent connected with the nature of the fruit which is many-seeded in most instances, namely a capsule or berry, but in others nut-like. Endosperm is present.
The family on one side is allied to the Contortæ (not only through the Loganiaceæ but also through the Apocynaceæ), and may be regarded as an epigynous continuation of this family; on the other side it is allied to the Valerianaceæ and Dipsacaceæ. Many points of agreement with the Cornaceæ and Araliaceæ are also found, and in fact several Caprifoliaceæ are distinguished from these by hardly any other feature than the gamopetalous corolla.