Densely tufted perennial, 4-33(-38) cm. Rhizome with tillers. Stem 0.3-0.7 mm diam., trigonous, scabrous along edges. Leaves to as long as stem, stiffly erect; sheaths pale to dark brown, to c. half of stem length; blades (1-)1.4-3.5 mm wide, flat, keeled, margins scabrous. Inflorescence unisexual or androgynous spike, 17-45 x 2-4 mm, female spikes or parts of spikes lax, male parts dense; female glumes 2.2-4.5 x 1-2 mm, lanceolate or narrowly ovate, obtuse to acute, often mucronate, mid-vein area green, sides orange-brown; male glumes (5-)7-8.5 x 1.6-2 mm, lanceolate, blunt, margins widely scarious; utricles 1.9-3.5 x 0.4-0.7 mm, obovate, veins scabrous, beak 0. Stigmas 3. Nut long exserted from utricles, 2.5-3.4 x 0.5-0.7 mm, stipe 0.4-0.7 mm, style base (1-)1.4-2 mm.