Tufted, usually erect perennials with slender, simple or branched culms. Ligule membranous, ± ciliate. Leaf-blade linear, flat or revolute. Inflorescence of subdigitate or paniculate racemes on short peduncles. Racemes bearing paired spikelets, naked below; rachis fragile, rachis segments and spikelet pedicels filiform, ± hairy, longitudinally grooved, groove ± hyaline. Spikelets ± hairy, one sessile, one pedicelled, each spikelet pair deciduous with adjacent segment of rachis attached. Pedicelled spikelet Ø, lemma, if present awnless, hyaline and nerveless. Sessile spikelet dorsally compressed, with small, obtuse, bearded callus, 2-flowered; lower floret Ø, upper floret ☿, awned. Glumes very dissimilar, ± membranous; lower 2-keeled, 5-9-nerved, sometimes with circular depression (pit) about the middle, upper narrower, 1-keeled, 1-4-nerved. Lower floret: lemma hyaline, nerveless. Upper floret: lemma reduced to a hyaline base topped by a twisted awn; palea small, or 0; lodicules distally fleshy, glabrous; stamens 3, or 1; ovary apex glabrous, styles ± terminal, free; caryopsis turgid, embryo ½ length of caryopsis, hilum punctiform or shortly elliptic.