Culms 60-120 cm, from knotty rhizomes. Leaves 30-60 cm, junction of the sheath and blade inconspicuous abaxially; blades 2-5 mm wide, in line with the sheaths, margins scabrous, otherwise glabrous or the adaxial surfaces inconspicuously pubescent to hirsute. Panicles 8-16 cm long, 2-3(5) cm wide; branches spreading to erect. Spikelets 3-4 mm long, 1.3-1.8 mm wide. Upper glumes and lower lemmas pubescent, hairs 0.6-1.5 mm, eventually spreading, usually purple-tinged; anthers 1-1.5 mm. Caryopses 1.2-1.4 mm. 2n = 20.