Culms erect, to 1 m high, nodes glabrous. Leaves glabrous (rarely the basal sheath pubescent); blade flat or inrolled, to 20 cm long, 2–5 mm wide, often scabrous on the upper surface; ligule papery, obtuse, 1–2 mm long. Inflorescence a cylindric panicle, 6–25 cm long, the spikelets typically overlapping and obscuring the axis and branches; glumes narrow-acuminate, 5–10 mm long, the upper often 1–2 mm longer than lower; lemma 4.5–8 mm long, shorter than glumes or rarely longer than lower glume, smooth; awn 22–40 mm long, sinuous, weakly twisted in lower part. Flowers Oct.–Mar.