Large, dense usually dioecious or gynodioecious perennial; culms erect, stout, to 4 m high.
Leaves with ligule a rim of hairs 2–3 mm long; blade folded in bud, c. 1 m long, scabrous, margins knife-sharp.
Inflorescence a large plume-like panicle barely exserted above the basal leaves, silvery white to pink, to c. 0.8 m long. Spikelets solitary, 2–6-flowered, 15–18 mm long, the male glabrous, the female with long silky hairs; rachilla disarticulating near the base of the internodes forming a stalk c. 0.5 mm long to the floret, upper part of the rachilla bearded, the lower part glabrous. Lower glume 9–14 mm long, upper 13–15 mm long. Lemmas 1-nerved, soft, tapering into a deciduous slender awn c. 1 mm long; female 13–15 mm long, male 9–12 mm long. Palea 3.5–4 mm long in female florets, c. 5 mm in male.