Zingiberaceae

Abstract

Perennial, aromatic herbs; rhizome sympodially branched, sometimes on stilt roots. Stems short, poorly developed, mostly lengthened by erect pseudostem formed by the leaf sheaths. Leaves distichous, sometimes appearing tufted, in lower part of shoot usually without blade; leaf sheath usually open; ligule present or absent; blade entire, elliptic, sometimes linear or broadly elliptic, glabrous or hairy, when young rolled up from one side to the other; midrib prominent; lateral veins in a pinnate-parallel arrangement; petiole present or absent; pulvinus usually absent (except Zingiber). Inflorescence terminal on the leafy shoot, or terminal on a short, separate, sheath-covered, leafless shoot arising directly from the rhizome, lax or congested, cylindric or fusiform, sometimes globose, with (1-)few-manyflowered, sometimes bracteolate cincinni axillary to the bracts of the inflorescence and then representing a thyrse, or rarely a raceme or a spike; bracteole obliquely adaxial to transverse, open to the base (= non-tubular), or tubular (but may split early), or absent. Flowers epigynous, bisexual, zygomorphic. Calyx tubular, usually 3-lobed or 3-dentate, sometimes split down 1 side. Corolla tubular at base; lobes three, varying in size and shape, the median posterior one often larger than the other ones and cucullate. Only the median posterior stamen of the inner whorl functional; the other 2 stamens of the inner whorl sterile and connate to form the petaloid labellum; 2 lateral staminodes of the outer whorl petaloid or inconspicuous, flanking the stamen or adnate to the labellum; the median anterior member of outer whorl always reduced; functional stamen with long or short filament, sometimes filament absent, anther dithecal, tetrasporangiate, thecae opening introrsely by longitudinal slits, occasionally dehiscing by pores, the connective often apically prolonged in a crest and sometimes also basally into spurs. Gynoecium 3-carpellate, ovary in its first stages always 3-locular, when fully developed either (incompletely) 3-locular with axile placentation or 1-locular with parietal or basal placentation. Style terminal, very thin, nearly always placed in a furrow of the filament and held between the thecae; stigma ± Wet, papillate, funnel-shaped, often ciliate, appearing on top of the anther. Nectaries 2, epigynous. Ovules ± many, anatropous, bitegmic, and crassinucellar. Fruit a dry or sometimes fleshy capsule, loculicidally dehiscent from apex to base by 3 valves, or irregularly dehiscent, or indehiscent, smooth, ridged or verrucose; in some genera fruits united in a syncarp. Seeds few to many, ovoid to ellipsoid or subglobose, sometimes angular, with an operculum next to the radicle, usually with a prominent, commonly lobed or lacerate aril; embryo straight, linear, central in the endosperm; perisperm abundant, starchy with large, compound starch grains. Germination hypogeal.