Description from Flora of China
Herbs, annual or perennial. Rhizomes present or absent. Culms usually tufted, 3-angled or compressed 3-angled, rarely triquetrous. Leaves basal, 3-ranked; ligule absent; leaf blade usually present. Involucral bracts (1 or)2-5(-8), leaflike, rarely very thin. Inflorescences terminal, a simple or rarely compound anthela; rays several, long or very short, or inflorescence capitate. Spikelets few to many, arranged into a short spike or capitulum at apex of rays, or fascicled; rachilla not articulate at base, persistent, wingless or narrowly winged. Glumes distichous, gradually deciduous from base to apex of rachilla at maturity, basal 1 or 2 usually without a flower but remaining ones each with a bisexual flower. Flowers without hypogynous bristles or scalelike perianth parts. Stamens 1-3; connective apex prominent or not prominent beyond anthers. Style base not swollen; stigmas 2, deciduous at maturity. Nutlet biconvex, slightly compressed or slightly turgid, one margin facing rachilla, puncticulate and reticulately striate or transversely undulately striate.
More than 70 species: Africa, America, Asia, Europe, oceanic islands; 11 species (three endemic) in China.
(Authors: Dai Lunkai (戴伦凯); Gordon C. Tucker, David A. Simpson)