Tufted perennial, 25-60 cm, with long subterranean stolons. Rhizome 1.5-3 mm diam., internodes long, dark scales disintegrating into fibres. Stem sharply trigonous, smooth. Leaves equalling stem length; sheaths 15-70 mm, dark to light brown, disintegrating into often net-like fibres; ligule 0.2-0.5 mm, light brown; blades 2-4 mm wide, flat to somewhat revolute, long-acuminate, margins and main veins scabrous. Inflorescence with 1-3 male spikes grouped closely together, 1-3 female spikes remote. Bracts sheath-less, equalling inflorescence. Male spikes 12-30 x 2-3 mm, from pale yellow to light brown, glumes 4.5-6 x c. 1.6 mm, obovate, obtuse, scarious. Female spikes 8-25 x 4-7 mm, from almost globular to cylindrical; glumes 3.7-4.2 x 1.6-2 mm, triangular, acute, midnerve area green, 3-nerved, margins widely scarious; utricles c. 4.5 x 1.9 mm, ovoid, obscurely nerved, all over spongy, greenish to light brown, hirsute to puberulent, beak c. 0.9 mm, slightly compressed, bidentate, greenish, ostiole margin white, ciliate. Stigmas 3. Nut 3 x 1.4 mm, incl. c. 0.4 mm style base and c. 0.2 mm stipe, trigonous, light brown, finely puncticulate.