閉鞘薑屬

Rhizomes horizontal, tuberous. Stem sometimes branched. Leaves spirally arranged; leaf blade oblong to lanceolate, often hairy; leaf sheath closed, tubular. Inflorescences terminal on the leafy shoot or lateral on separate, short, leafless shoots arising from rhizomes, conical, densely many flowered; bracts imbricate, 1- or 2-flowered. Calyx 3-lobed or -toothed at apex, usually greenish. Corolla tube equaling or longer than calyx. Labellum obovate, large, margin undulate and incurved. Fertile stamen more or less petaloid; anther locules linear. Ovary 3-loculed; ovules many per locule, superposed. Style filiform; stigma funnelform. Stylodes absent. Capsules subglobose or ovoid; calyx persistent. Seeds many, black; aril lacerate.

About 90 species: tropical and subtropical regions; one species in Taiwan.

Lower Taxon

• Costus speciosus (J. König) Smith