Rhizomatous perennials. Leaf-blades flat; ligules membranous, ciliate. Inflorescence a spike-like panicle. Spikelets paired (one sessile, one pedicellate), each with 2 florets, disarticulating below the glumes; glumes 2, similar, 3–9-nerved, membranous, subtended by long silky hairs which remain attached to the spikelet after disarticulation; lower floret male (rarely) or sterile, usually lacking a palea; upper floret bisexual paleate; both considerably shorter than glumes and both thinly membranous.