Tufted annual; culms 2-25 cm high, erect or prostrate and ascending. Leaf-blades flat or convolute when dry, 0.5-3(-8) cm long, 1-2 mm wide, scabrid above; uppermost sheath inflated. Spikes solitary, rigid, curved or rarely straight, 1-10 cm long, cylindrical, the joints deeply hollowed on one side, breaking horizontally beneath each spikelet at maturity. Spikelets 4-8 mm long, the lowest nearly always included on the uppermost sheath; glumes equal, as long as the spikelet, lanceolate-acuminate, the keel not winged; lemma with one side adjacent to the rhachis; anthers 0.5-1 mm long.