Large tufts to spreading clumps, with short, stout, upright or spreading rhizomes. Culms 400-550 × 0.7-0.9 mm, glabrous, trigonous, > leaves; leaf sheaths up to 30 mm long, yellow-brown, nerves light brown. Leaves 6-1 1 per culm, up to 250-500(-550) × 2-5 mm, weakly channelled, upright to spreading, often curved, green; adaxial surface scabrid on proximal part, otherwise glabrous; abaxial surface keeled, keel scabrid, otherwise glabrous; margin scabrid; apex acute, trigonous, scabrid. Spikes linear, up to 55 mm long, 2-3 mm wide; female florets proximal, 15-24, internodes 3.5 mm long at base of spike, decreasing to 0.6 mm long above; male florets distal, 15-20, imbricate. Spike sometimes subtended by a leaflike bract; bract 15-95 × 0.2-1.2 mm, channelled, margins and abaxial midrib scabrid, apex trigonous. Male glumes 3.5-4.0 × c. 1.0 mm, narrow elliptic- lanceolate to narrow elliptic, hyaline, midrib green with 1 prominent central nerve, light brown at maturity, apex acute, margin membranous. Filaments c. 2 mm long; anthers c. 1.2 mm long. Female glumes 3.5-4.0 × 1.0-1.2 mm, ± equal in length to utricles, elliptic lanceolate to narrow elliptic, hyaline, deciduous; midrib green, light brown at maturity, with 1 prominent central nerve, apex acute to subacute, margins membranous; lowest 1(-2) glumes sometimes with prominent leaflike awns up to 50 mm long, slender, filiform, scabrid. Utricles 4.2-4.3 × 1.2-1.3 mm, planoconvex, ovate to elliptic, glabrous, light green when young, light brown at maturity, lateral nerves ± prominent but not conspicuous, stipe and beak both narrow, each c. 1 mm long; rachilla 2.4-3.6 mm long. Nuts 2.2- 2.4 × 1.0-1.2 mm, oblong, light green to silver- green. FL Dec; FT Jan-Apr.

A U. uncinata (L.f.) Kük. spica minore et angustiore et flosculos femineos pauciores habente. A numero chromosomatum singulari (2n = 132) praeter distinguenda.