Description from Flora of China
Herbs, perennials. Culms tufted, 3-angled to obtusely 3-angled, rarely terete, few to many nodose. Leaves basal and cauline; leaf blade linear, grasslike, ligulate, base sheathing. Involucral bracts leaflike, spreading. Inflorescence a terminal corymbiform anthela, with many spikelets. Spikelets ovoid to ellipsoid, generally rather small. Glumes spirally arranged, deciduous, each subtending a flower. Flowers bisexual. Perianth bristles 3-6, as long as to much longer than nutlet, deciduous with nutlet. Stamens 1-3. Style base not thickened, persistent; stigmas 2 or 3. Nutlet obovoid to ellipsoid, compressed 3-sided to biconvex, smooth, apex beaked.
About 35 species: mostly in temperate regions of N Hemisphere, greatest diversity in North America; 12 species (four endemic) in China.
(Authors: Liang Songyun (梁松筠 Liang Song-jun); Gordon C. Tucker)