Description from Flora of China
Herbs, perennial or annual, sometimes with a creeping rhizome. Culms tufted or solitary, usually pubescent, nodose. Leaves mostly cauline, pubescent or glabrous; sheath usually completely surrounding culm; ligule tubular, hyaline; leaf blade usually elongate, linear to lanceolate. Involucral bracts leaflike, sheathing at base. Inflorescences paniculiform, with few to many glomerulate clusters or sessile spikelets at few to several nodes. Spikelets ovoid to ellipsoid, terete, many flowered, usually pubescent. Glumes spirally imbricately arranged, obovate, broadly elliptic, or oblong, each subtending a bisexual flower but basal 1 or 2 empty, apex obtuse and awned. Perianth bristles 3 or 6, 3 outer ones needlelike (sometimes reduced or absent), 3 inner ones squamellate and alternate with outer whorl. Stamens 3. Style not or hardly dilated at base, continuous with ovary, glabrous; stigmas 3. Nutlet ± stipitate, obovoid to ovoid, 3-sided, ± smooth or tuberculate.
About 30 species: warm regions of the world, most species in tropical Africa and tropical America; three species (one endemic) in China.
(Authors: Liang Songyun (梁松筠 Liang Song-jun); Gordon C. Tucker, Jeremy J. Bruhl)