Description from Flora of China
Annual or perennial. Culms erect or decumbent or creeping, many-noded. Leaf blades narrowly lanceolate to ovate, margin frequently white and thickened; ligule a line of stiff hairs. Inflorescence an open or contracted panicle, branches and pedicels sometimes spotted with yellow glandular patches. Spikelets with 2 florets, florets both bisexual or lower floret bisexual or male and upper floret male or female, separated by a short internode or contiguous, disarticulating below each floret; glumes falling soon after florets, subequal, 3/4 to as long as spikelet, 5–9-veined; lower lemma variable, resembling the upper or of different size and texture; upper lemma orbicular to broadly elliptic, papery to leathery, glabrous or pubescent with short curved hairs, 5–7-veined, obtuse. Stamens 3. Caryopsis ellipsoid or subglobose.
About 90 species:throughout the tropics, but mainly in Asia; 18 species (four endemic) in China.