Tufted, rhizomatous or stoloniferous annuals or perennials. Leaf-blades flat or inrolled; ligules membranous. Inflorescence a panicle. Spikelets laterally compressed, 2–15-flowered, breaking up above the glumes and between the florets; glumes 2, 1–3-nerved; lemma mostly 5-nerved, keeled, resembling the glumes, unawned, often with fine, thready hairs (web) along the basal callus; palea present.
About 500 species, cosmopolitan; 46 species occurring in Australia (6 naturalized), 35 in Victoria (5 naturalized). Although most specimens can be satisfactorily placed, occasional plants are encountered which appear to combine features of two (or more) species. Problematic specimens are probably a reflection of the imperfect state of the genus' taxonomy as often as they are a result of hybridization.