Description from Flora of China
Herbs, annual [or perennial]. Culms tufted, very slender. Leaves with a leaf blade or rarely reduced to a bladeless sheath, mouth with lax white hairs; leaf blade filiform to linear, margin often involute. Involucral bracts leaflike or setaceous. Inflorescence a terminal simple or compound anthela or capitate, sometimes reduced to a single spikelet. Spikelets ovoid to ellipsoid, many flowered. Glumes spirally arranged or rarely distichous, herbaceous or membranous, deciduous, subtending a flower but basal 1 or 2 empty. Flowers bisexual. Perianth bristles absent. Stamens (1 or)2(or 3). Style filiform, base thickened, bulbous, and persistent in fruit; stigmas 3. Nutlet obovoid to obpyriform, 3-sided.
About 100 species: tropical to temperate regions worldwide with high concentration of species in tropical Africa and tropical America; three species in China.
(Authors: Liang Songyun (梁松筠 Liang Song-jun); Gordon C. Tucker)