Annuals or perennials. Inflorescence terminal or axillary, of paired or digitate (occasionally single) racemes, sometimes numerous and crowded into a spathate false panicle; racemes lacking homogamous pairs; internodes and pedicels filiform to obovoid. Sessile spikelet dorsally flattened or squeezed between pedicel and internode; callus obtuse, inserted in the concave top of the internode; lower glume membranous to coriaceous, mostly flat, concave or deeply grooved on the back, 2-keeled; upper glume with or without an awn; lower floret reduced to a hyaline lemma; upper lemma hyaline, 2-lobed, with a conspicuous awn from the sinus. Pedicellate spikelet male or barren (sometimes 0), usually awnless.  Similar to Ischaemum. See the note under that genus.