Greyish green perennial, 10-50(-80) cm, with long creeping rhizome. Rhizome sturdy, 1.5-3 mm in diam., with rather short internodes, covered with fibrous scales. Stem obtusely to sharply trigonous, distally more or less scabrous along the edges. Leaves 1/3 - 2/3 of stem length; sheaths 20-50 mm, outermost pale brown, mouth margin almost straight; ligule c. 0.2 mm; blades 1-3 mm wide, conduplicate to involute, seldom flat, adaxial side papillose, margins and mid-vein scabrous towards apex. Inflorescence 10-40 mm, of (3-)5-7(-15) overlapping androgynous spikes. Bracts sheath-less, narrow, lowest sometimes equalling inflorescence. Spikes 5-13 mm, globular to ellipsoid, at first variegated green and brown, later brown; female glumes 3-5 x 1.6-2.8 mm, light-brown with darker mid-vein and scarious margins, frequently with arista to 1.5 mm; utricles 3.2-4.7 x 1.5-2.1 mm, ellipsoid, plano-convex, conspicuously spongy, yellowish to dark-brown, with or without pronounced veins, sometimes with short stipe, beak 0.7-1.1 mm, smooth or slightly scabrous, basal part narrowly winged, ostiole bidentate or oblique, with scarious margin. Nut c. 2 x 1.5 mm, plano-convex, widely obovoid, light-brown to brown, sometimes with short style base.