Perennial 1.5-4.0 m tall. Leaves linear or broadly linear; trigonous above the sheath, angularly keeled dorsally, 3-angled; lamina 25-40 mm broad. Upper part flat, about as long as inflorescence; male and female parts separate; axis of the male spike covered with hairs; female spike cylindric, blackish brown or brown; pistillodes present; female flowers bracteate; stigma lanceolate, bracts spathulate and longer than the hairs.