Loosely to densely cespitose. Culms 5-15-(25) cm, trigonous, slightly scabrid above; basal sheaths light brown or greyish. Leaves mostly shorter than the culms, 0.8-1.5 mm wide, slightly channelled, tips obtuse to subacute. Inflorescence mostly a single dark brown terminal head, 8-17 mm long, 5--8 mm wide, consisting of 2-3-(4) contiguous spikes; subtending bracts small, not conspicuously different from scales, but often with short awn. Spikes androgynous, 5-8 mm long, male flowers at base. Scales as long as or slightly shorter than the perigynia, broadly ovate, obtuse to subacute, reddish brown to blackish, with a paler midrib, hyaline margin narrow. Perigynia 2.5--3-(3:3) mm long × 1.4--1.6 mm wide, piano-convex, oblong-ovate, weakly nerved, margins glabrous, contracted abruptly to a narrow, usually very dark, short beak (0.4--0.6 mm). Achene 1.3-1.6 mm long, 0.9-1.2 mm wide, oblong-ovoid to almost orbicular, light to dark brown. Stigmas 2.