Annual; culms up to 70(100) cm high, usually geniculately ascending and rooting at the lower nodes, frequently shortly stoloniferous and mat-forming, less often erect. Leaf-blades flat, 3-25 cm long, 2.5-7.5 mm wide, papillose-hispid especially along the margins. Inflorescence composed of (1)3-9 linear to narrowly oblong spikes 1.2-6.5 cm long. Spikelets 3-4-flowered, broadly ovate, 3.5-4.5 mm long; glumes subequal, 1.5-2.2 mm long, the lower lanceolate in profile with a thick scabrid keel, the upper elliptic to narrowly obovate in profile, the smooth keel extended into a stout divergent scabrid awn half to twice as long as the glume; lemmas narrowly ovate to ovate in profile, 2.6-4 mm long, the keel gibbous, concave and scabrid above the middle and often extended into a stout cusp or mucro up to 1 mm long; palea-keels winged or wingless; anthers 0.25-0.8 mm long. Grain about 1 mm long, broadly obovate to obtriangular in profile, transversely rugose.