Tufted perennial. Culms erect, ± rigid, terete, striate, nodeless to 2-noded, 6–45 cm high, 0.5–1.2 mm diam. Leaves filiform, numerous; blade to 30 cm long; sheath straw-coloured (basal leaves) to very dark red-brown (cauline leaves), striate to smooth, shining; mouth glabrous; ligule present. Inflorescence narrow, erect, 2–15 cm long, with spikelets clustered at 2–4 distant nodes; lowest involucral bract to 5 cm long. Spikelets narrow-ovate, acute, 2–6-flowered, 4–7 mm long; glumes 4–8, lowest 2 empty, acute, dark yellow-brown to red-brown, shining, with glabrous, hyaline margins; fertile glumes 3.5–5.5 mm long; hypogynous bristles absent or several minute. Nut trigonous, obovoid, prominently 3-ribbed, smooth or minutely reticulate, glabrous, ± shining, whitish to grey-brown, 0.7–1.5 mm long, 0.5–0.8 mm diam. Flowers spring–summer.
LoM, Wim, GleP, Brid, VVP, VRiv, GipP, OtP, WaP, Gold, CVU, GGr, DunT, NIS, EGL, EGU, WPro, HSF, HNF, Strz. Also SA, Tas. On swamp margins and in wet heathland sites.
Superficially resembling the widespread and variable Schoenus apogon, but distinguished by the reduced hypogynous bristles, the virtually smooth nut and by the numerous filiform leaves at the base of the plant.
