Plants perennial, densely cespitose, 15-50(-60) cm; rhizomes absent. Culms erect or arching, leafy toward base, filiform, terete, wiry. Leaves overtopped by culm; blades linear to filiform, channeled, 0.3-0.5 mm wide, margins deeply involute, apex setaceous. Inflorescences: spikelet clusters 1-2(-3), dense to open, narrowly to broadly turbinate; branches capillary, variously elongate; leafy bracts setaceous, equaling or exceeding clusters. Spikelets variously brown, ellipsoid, 2-3 mm, apex sharply acute; fertile scales ovate to nearly orbiculate, rounded, 1.2-1.8 mm, apiculate, convex cupulate, midrib slender, mostly included. Flowers: perianth absent. Fruits 2-3 per spikelet, 0.7-0.9(-1) mm; body pale, obovoid-lenticular, (0.5-)0.6-0.9 × 0.4-0.5 mm, margin wirelike; surfaces transversely rugulose; tubercle buttonlike, depressed triangular, 0.05-0.1 mm, base lunate atop rounded fruit body. Fruiting summer-fall. Moist sands, peats and silts of low meadows, savannas, bogs, seeps, pond shores; 0-300 m; Ala., Fla., Ga., La., Miss., N.C., S.C., Tex.; Mexico; West Indies; Central America.