Description from Flora of China
Perennials or annuals. Culms tufted, or with creeping rhizomes and stolons. Leaf blades linear or narrowly lanceolate, flat; ligule membranous. Inflorescence composed of single, digitate or scattered racemes; rachis flat, often winged; spikelets single or paired, pedicellate in 2–4 rows, densely crowded, lower lemma abaxial. Spikelets orbicular, ovate or elliptic plano-convex; lower glume absent or rarely present as a small scale; upper glume as long as spikelet or nearly so, rarely absent, convex, membranous to subpapery, 3–7-veined; lower lemma resembling upper glume, flat, neuter without palea; upper lemma usually coriaceous to crustaceous, rarely softer, margins inrolled, apex obtuse to apiculate. x = 10.
This genus includes a number of good forage grasses and also some widespread weeds.
About 330 species:tropical and warm-temperate regions, especially in the New World; 16 species (two endemic, eight introduced) in China.
(Authors: Chen Shouliang (陈守良); Sylvia M. Phillips)