Tufted perennial, shortly rhizomatous. Culms rigid, terete, glabrous, striate but smooth, mostly 10–30 cm high, 0.5–1.5 mm diam. Leaf-blades ± stiff, channelled, flattened distally, mostly shorter than culms, 1.5–3 mm wide; sheaths red-brown or dark yellow-brown near base, often paler above, often striate, shining. Inflorescence a loose cluster of 10–20 spikelets, 3–6 cm long, with 1 or 2 involucral bracts longer than inflorescence. Spikelets 13–18 mm long; glumes acute, keeled above, straw-coloured or yellowish or red-dotted, the two outer small and empty, the two larger glumes 10–16 mm long, with a ± hyaline, ± linear empty glume above; hypogynous bristles 12–15 mm long, yellow to pale red-brown, plumose except often the tip antrorsely scabrous for up to 1 mm. Nut narrow-ellipsoid, pale red-brown, minutely reticulate, glistening, on a short stipe c. 0.5 mm long, the body 3.5–4.5 mm long, c. 1.2 mm diam., the persistent style-base 6–9 mm long. Flowers summer.
EGU, HSF, HNF, VAlp. Also NSW, ACT. Occurs in similar habitats to C. alpina, but widespread throughout treeless alpine and subalpine areas above c. 1400 m.
