Plants perennial; often dioecious or monoecious; cespitose. Culms 2-7 m, erect, densely clumped. Leaves primarily basal; sheaths open, often overlapping, glabrous or hairy; auricles absent; ligules of hairs; blades to 2 m, flat to folded, arching, edges usually sharply serrate. Inflorescences terminal, plumose panicles, 30-130 cm, subtended by a long, ciliate bract; branches stiff to flexible. Spikelets somewhat laterally compressed, usually unisexual, sometimes bisexual, with 2-9 unisexual florets; disarticulation above the glumes and below the florets. Glumes unequal, nearly as long as the spikelets, hyaline, 1-veined; calluses pilose; lemmas 3-5(7)-veined, long-acuminate, bifid and awned or entire and mucronate; lemmas of pistillate and bisexual florets usually long-sericeous; lemmas of staminate florets less hairy or glabrous; lodicules 2, cuneate and irregularly lobed, ciliate; paleas about 1/2 as long as the lemmas, 2-veined; anthers of bisexual florets 3, 1.5-6 mm, those of the pistillate florets smaller or absent. Caryopses 1.5-3 mm; hila linear, about 1/2 as long as the caryopses; embryos usually shorter than 1 mm. x = 9. Name from the Spanish, cortada, cutting, referring to the sharply serrate blades.