Perennial, 40-90 cm. Rhizome long, woody. Stem 1.5-2.5 mm diam., noded, trigonous, smooth. Leaves longer than stem; sheaths dark, often disintegrating into fibres; blades 4-10 mm wide, folded, prominent nerves scabrous. Inflorescence 20-40 cm, partial inflorescences remote; partial inflorescences 2-6, ovoid-pyramidal, rather dense, lower long pedunculate, peduncles scabrous. Bracts longer than inflorescence, long vaginate. Spikes 5-6 mm, female and male parts almost equal; glumes ovate, mucronate, brown. Utricles longer than glumes, 3.5-4 mm, ovoid or ellipsoid, slightly inflated, pubescent above; beak abruptly contracted, often curved, scabrous, bidentate. Stigmas 3. Nut c. 2 mm, ovoid to ellipsoid, trigonous.