Robust, rhizomatous, to 1.8 m high. Male spikes with long-awned glumes; female spikes in twos or threes at each inflorescence-node, red-brown with long-awned glumes, peduncles erect to pendulous. Utricles 2-3 mm long; beak minute. Stigmas 2.

Rhizomatous; in robust, dark green clumps to 180 cm. tall. Rhizome 5–10 mm. diam., closely covered with red-brown sheaths. Culms 30–90–(150) cm. × 3–5 mm., triquetrous, scabrid; basal sheaths red-brown, margins shredding into fibres. Lvs > culms, 4–10–(17) mm. wide, double-folded, margins and keel finely scabrid. Spikes 7–13–(16), in both sexes varying from 1–8 cm. in length, distant, peduncles us. ± = or > spikes, stout, stiff and erect, or more slender and drooping; upper (2)–4–5–(7) spikes male, c. (4)–6 mm. diam. (excluding very prominent awns); lower spikes female, 5–8 mm. diam., lowest spikes geminate or ternate. Glumes of male spikes ± truncate to acute, with scabrid awns occ. up to 1 cm. long; glumes of female spikes (excluding awn) ± = utricles, narrow-lanceolate to elliptic-lanceolate, acute, red-brown, membr., with lighter brown, broad midrib produced to a finely scabrid awn up to 6 mm. long (awn occ. very dark red). Utricles c. 2–3 × 1.5–2 mm., plano-convex to biconvex, elliptic-obovoid, ± turgid, light yellow-brown, sts red-brown towards the base, nerves 5 or more on each face, margins smooth; beak c. 0.2–(0.4) mm. long, often lighter brown, very narrow, orifice glab., very slightly bifid; stipe c. 0.3 mm. long, narrow. Stigmas 2. Nut 1.5–2 mm. long, biconvex, obovoid, shining, brown.