Perennials; culms solid, tufted, without stolons. Leaf-blades with inrolled margins when in bud; leaf-sheath keeled or rounded on back, with tubercle-based hairs, especially on nodes and often at the mouth; ligule short, truncate, ciliate or glabrous; blades linear, glabrous or sparingly hairy, margins revolute when dry. Inflorescence composed of spike-like racemes with articulate rachis, the central axis branched, racemes digitately or racemosely arranged, or combined into panicles. Spikelets in alternate pairs, the one pedicelled, the other sessile; spikelets dorsiventrally arranged, the uppermost pair forming a triad with terminal spikelet; rachis of racemes and also pedicels with translucent longitudinal groove, hairy throughout, or partly so along edges; spikelets lanceolate, dorsally compressed, often with 1 or more depressions or pits, aromatic. Sessile spikelet with fascicle of hairs at base, falling together with adjacent rachis joint and pedicel; glume herbaceous, the lower glume as long as spikelet, smooth or with 1 or more depressions and/or pits, 7-11-nerved; upper glume equally long or somewhat shorter, boat-shaped, keeled, hyaline, 3-nerved; lemmas and paleas thin; lower lemma shorter than lower glume, nerveless; lower palea absent; upper lemma ; consisting of geniculate awn with hyaline stipe-like base; upper palea small or absent; lodicules 2; stamens 3; ovary glabrous, the styles 2, the stigmas plumose, exserted laterally. Caryopsis oblong, obtuse, dorsally compressed, the side of hilum flat, side of embryo convex; embryo usually half as long as caryopsis. Pedicelled spikelet resembling sessile spikelet, but muticous and staminate or neuter, often without pits; upper lemma and palea absent; stamens 3-0.
About 20 species distributed in warm regions of the world.
Three species and one variety are commonly found on the plains of Taiwan.