Annuals or perennials. Leaves: lamina linear. Inflorescence of solitary or digitate racemes, each raceme bearing paired spikelets. Sessile spikelet male or barren and awnless, otherwise resembling the pedicellate. Pedicellate spikelet bisexual with pungent callus; lower glume grey-brown, convex on the back; lower floret reduced to a hyaline lemma; upper lemma entire, with a hairy awn from the apex. The genus is unusual in that the sessile spikelet is male or barren and awnless.