Perennials, basal internodes often swollen and bulb-like. Leaves flat. Inflorescence a panicle. Spikelets 2-flowered, often with a rudimentary floret above; lower floret male with a geniculate awn inserted in the basal one-third, upper floret female or bisexual, usually with a short, straight bristle or awn, rarely both florets bisexual and awned; glumes persistent, unequal, hyaline, the lower 1–3-nerved, the upper 3–5-nerved; lemma 5–9-nerved; palea shorter than lemma. Florets falling as a unit at maturity.