Plants aggregated in dense tussocks; rhizomes branching, short, tough, fibrous. Culms: fertile ones upright or nearly so; nodes without axillary bulblets. Leaves 4–7 per culm; sheaths of proximal leaves brown; proximal sheaths and blades with septa few to many, conspicuous or inconspicuous; blades 25–63 cm × 3–6 mm. Inflorescences terminal; rays ascending or sometimes spreading, scabrous throughout or main branches smooth proximally, rays rarely with axillary bulblets; bases of involucral bracts usually blackish, not glutinous. Spikelets in open cymes, central spikelet of each cyme sessile, others usually pedicellate, spikelets ovoid or ellipsoid, 4–7 × 2–2.7 mm; scales usually blackish, at least distally, oblong-ovate or oblong-elliptic, 1.3–1.8 mm, apex rounded or very weakly apiculate, apiculus (if present) to 0.05 mm. Flowers: perianth bristles persistent, 6, slender, contorted, much longer than achene, smooth, projecting beyond scales, mature inflorescence appearing woolly; styles 3-fid. Achenes whitish, elliptic or obovate in outline, plumply trigonous or plano-convex, 0.7– 0.9 × 0.4–0.5 mm. 2n = 68.