Annuals. Leaves flat. Inflorescence a distichous spike. Spikelets solitary at each node of the rachis, 2–9-flowered, the uppermost usually sterile; glumes equal, papery, truncate, toothed or awned; lemma hardened, scabrous.
Due partly to a complex series of polyploids and partly to the range of published interpretations, the genus comprises 1 to as many as c. 20 species, from Europe, the Mediterranean and Asia.