Herbs, perennial, cespitose; rhizomes oblique. Culms roundly trigonous, 20-50(-80) cm × 1-3 mm, glabrous. Leaves 3-11, V-shaped, 12-40 cm. Inflorescences: heads loosely to rather densely hemispheric, 15-30 mm diam.; rays 5-10, 2-12 cm; 2d order rays occasionally produced, 5-25 mm; bracts 4-8, approximately horizontal to ascending at 30°, V-shaped, 10-36 cm × 1.5-4 mm, margins glabrous. Spikelets (4-)10-30, greenish, grayish, or stramineous, oblong to linear-oblong, compressed, (5-)7-10(-35) × 2-3 mm; floral scales 10-25(-85), laterally yellowish brown, medially yellowish or brownish, laterally ribless, medially 2-ribbed with groove between ribs, broadly ovate (widest in proximal 1/2), (1.2-)1.5-2 × 1.2-2 mm, apex obtuse (declined (45-)60-90º from rachilla). Flowers: stamen 1; anthers oblong, 0.8-1.2 mm, connective not prolonged; styles basally thickened, confluent with summit of achene, 0.6-1.2 mm; stigmas 0.3-0.6 mm. Achenes reddish brown to dark purplish brown, dull or more often iridescent, stipitate, broadly ellipsoid, 1-1.5 mm × 0.4-0.6(-0.7) mm, base cuneate to ± attenuate, stipe 0.1-0.2 mm, apex acute, beak 0.1-0.5 mm, surfaces reticulate with network of low ridges.

Fruiting summer. Damp, disturbed soils, ditches, marshes; 0-200 m; Fla., Ga., La., Miss., Pa., Tex.; Mexico; Central America; South America.

In Pennsylvania, Cyperus ochraceus has been recorded in areas where ballast has been discarded.