Herbs, annual, cespitose. Culms 1-10(-25), roundly trigonous, 3-12 cm × 0.3-0.8 mm, glabrous. Leaves 1-3-(4), 1-6 cm × 1(-1.5) mm. Inflorescences: if rays absent heads single, dense, sessile, digitate, 5-20 × 10-30 mm, single heads 10-30(-50) mm; rays usually absent, if present 1-8 cm; 2d order rays infrequently present, 1-2 cm; bracts 3-6, erect to oblique, flat to V-shaped,(0.5-)2-10(-15) cm × 0.5-2 mm. Spikelets 5-10(-20), linear to linear-lanceoloid, (5-)8-12(-35) × 1.6-2.3(-2.5) mm; floral scales (6-)16-30(-76), laterally glossy reddish brown to brown, medially greenish, sometimes also reddish or brownish, laterally ribless, medially strongly 3-ribbed, ovate-lanceolate, 1.9-2(-2.3) mm (including prominent excurved cusp of 0.3-0.5 mm) × 0.8-1.1 mm, apex truncate, emarginate, or cuspidate. Flowers: stamens (1-)2-3; anthers ellipsoid, 0.3 mm, connectives not prolonged; styles 0.3-0.4 mm; stigmas 0.4-0.7 mm. Achenes brown, slightly stipitate, obovoid to oblong, 0.8-0.9 × 0.4-0.5 mm, apex abruptly apiculate, surfaces papillose.

Fruiting summer. Seasonally wet, sandy soils; 500 m; Ariz.; Mexico; Central America; South America; Asia; Africa.