Culms 8-38(-80) cm tall, slightly slender, compressed cylindric, sometimes obtusely 3-angled at apical part, smooth. Leaves several, basal, shorter than to equaling culm; sheath short, usually split; leaf blade 2-3 mm wide, flat, apical margin spinulose. Involucral bracts 3-5, leaflike, basal 2 or 3 longer than inflorescence. Inflorescence a compound anthela; rays 3-7, mostly to 4.5 cm, unequal in length, each with (0-)3-6 raylets; raylets less than 1.5 cm. Spikes globose, 5-9 mm in diam., with 6-15 densely clustered spikelets. Spikelets broadly ellipsoid to ellipsoid, ca. 3 × 1.5-2 mm, strongly compressed, 1- or 2-flowered. Glumes yellowish brown, boat-shaped, 3.5-4 mm, membranous, laterally 1-veined, keel glaucous, broadly winged, and extending into an apical mucro. Stamens 3; anthers oblong. Style short; stigmas 3, slightly longer than style, laxly papilliferous. Nutlet dark reddish brown, narrowly oblong, 3-sided with sharp angles, 2.7-3 mm, densely puncticulate, apex acuminate. Fl. and fr. Jun-Sep. 2n = 10.