Loosely tufted annual; culms 8-70 cm high, erect or ascending. Leaf-blades flat, 2-20 cm long, 14 mm wide. Panicle elliptic to ovate, 4-25 cm long, open, the lowest branches whorled (except in the smallest panicles) and nearly always with a few long white hairs in the axils. Spikelets 4-14-flowered, linear, 3-7 mm long, 0.7-1.2 mm wide, purplish-green, the florets ± appressed to the rhachilla, breaking up from the base, the rhachilla persistent; glumes hyaline, unequal, the lower a narrowly ovate nerveless scale 0.5-0.7 mm long, the .upper ovate, 1 mm long, with a single indistinct nerve; lemmas broadly ovate, 1-1.6 mm long, obtuse to subacute; palea falling soon after the lemma (usually persistent in temperate regions), the keel scaberulous; anthers 3, 0.2-0.3 mm long. Caryopsis ellipsoid with one side straight, 0.6-1 mm long, somewhat laterally compressed.