Order XVII. Zingiberaceae, Lindl.—Gingerworts.
Drimyrhizeae, Vent.—Scitamineae, R. Brown.
Characters.—Calyx superior, tubular, 3-lobed, short. Corolla tubular, irregular, with 6 segments in 2 whorls; the outer 3-parted, nearly equal, or with the odd segment sometimes differently shaped; the inner (sterile stamens) 3-parted, with the intermediate segment (labellum) larger than the rest, and often 3 lobed, the lateral segments sometimes nearly albortive. Stamens 3, distinct, of which the 2 lateral are abortive, and the intermediate one fertile; this placed opposite the labellum, and arising from the base of the intermediate segment of the outer series of the corolla. Filament not petaloid, often extended beyond the anther in the shape of a lobed or entire appendage. Anther 2-celled, opening longitudinally, its lobes often embracing the upper part of the style. Pollen globose, smooth. Ovary 3-celled, sometimes imperfectly so; ovules several, attached to a placenta in the axis; style filiform; stigma dilated, hollow. Fruit usually capsular, 3-celled, many seeded [sometimes by abortion 1-celled]; occasionally berried (the dissepiments generally central, proceeding from the axis of the valves, at last usually separate from the latter, and of a different texture, R. Br.). Seeds roundish or angular, with or without an aril (albumen floury, its substance radiating, and deficient near the hilum, R. Br.); embryo enclosed within a peculiar membrane (vitellus, R. Br. Prodr. membrane of the amnios, ibid, in King's Voyage, 21), with which it does not cohere.—Aromatic, tropical, herbaceous plants. Rhizome creeping, often jointed. Stem formed of the cohering base of the leaves, never branching. Leaves simple, sheathing their lamina, often separated from the sheath by a taper neck, and having a single midrib, from which very numerous, simple, crowded veins diverge at an acute angle. Inflorescence either a dense spike, or a raceme, or a sort of panicle, terminal or radical. Flowers arising from among spathaceous membranous bracts, in which they usually lie in pairs. (Lindley.)
Properties.—The rhizomes contain a volatile oil and resin, which confer on them aromatic or acro-aromatic qualities. Many of them abound in starch, the particles of which (like those of plantain starch, see ante, p. 223) are flattened disks. This is sometimes extracted and used as food. Some of them are remarkable for the yellow colouring matter which they yield.
The seeds also contain volatile oil and resin; and possess aromatic or acro-aromatic qualities.