Culms 5-20(-35) cm. Leaves: basal sheaths somewhat glossy, bladeless; blades filiform, 2-20 cm × 0.2-0.5 mm. Inflorescences simple, 10-30 × 2-3 mm; proximal spikelets 2-flowered and androgynous, rarely 1-flowered and pistillate; distal spikelets 1-flowered, staminate. Scales brown, ovate, 2-3.5 mm, margins hyaline, midvein distinct almost to tip, apex obtuse or cuspidate. Anthers 1-1.5 mm. Perigynia brown, 2-3.5 mm, margins free to base, smooth. Achenes 2-2.8 mm. 2n = 52, 56-58. Fruiting summer. Tundra, grassland, heaths, bare rocky, dry to wet ground; 0-3500 m; Greenland; Alta., B.C., Man., Nfld. and Labr., N.W.T., Nunavut, Ont., Que., Yukon; Alaska, Calif., Colo., Idaho, N.Mex., Oreg., Utah, Wyo.; Eurasia.