Dense clumps up to 90 cm tall. Stems stout, erect, 3-angled, smooth or slightly scabrid on angles below inflorescence. Leaves 5-8 mm wide, ± = stems, flat, many small internal septa noticeable when dry; sheaths red to almost black. Inflorescence of large approximate spikes each with long leaf-like bract. Male spike 1, 5-6 cm × 2 mm, peduncle short; glumes narrow with long scabrid awns. Female spikes usually 3, upper sessile, rest shortly pedunculate, 2-4 × ± 1.5 cm, glumes much < utricles except at base of spike, narrow, hyaline, with an extremely long awn. Utricles 6-9 × 2-4 mm, strongly inflated, distinctly nerved, shining, smooth, greenish-brown, beak very narrow, bifid, c. ½ length of utricle. Stigmas 3. Nut trigonous, obovate, style strongly curved above base.