Description from Flora of China
Herbs, perennial or rarely annual, with rhizomes or only fibrous roots. Culms tufted or scattered, usually slightly slender, rarely slightly stout. Leaves basal, 3-ranked; ligule absent; leaf blade elongated or reduced. Involucral bracts spreading, leaflike. Inflorescences terminal, capitate, with 1-3 spikes. Spikes sessile, capitate, with densely numerous spikelets. Spikelets short, compressed, each usually with 1 or 2(-5) bisexual flowers; rachilla articulate near base, deciduous at articulation when mature. Glumes distichous, persistent on rachilla and deciduous with it, basal 2 without a flower, apicalmost rarely with a male flower, remaining ones each with a bisexual flower. Flowers without perianth bristles or scalelike perianth parts. Style base not swollen, deciduous; stigmas 2. Nutlet compressed biconvex, one angle toward rachilla.
About 75 species: tropics and warm temperate regions worldwide; seven species (one introduced) in China.
(Authors: Dai Lunkai (戴伦凯); Gordon C. Tucker, David A. Simpson)