Psilocarya scirpoides Torrey, Ann. Lyceum Nat. Hist. New York 3: 360. 1836

Plants annual, cespitose, (20–)30–80(–100) cm; rhizomes absent. Culms erect or ascending, leafy, nearly terete or obscurely angular, many-ribbed, stiff. Leaves exceeding or exceeded by inflorescences; blades linear, proximally flat, 1–5 mm wide, apex trigonous, tapering. Inflorescences terminal and axillary, clusters of corymbs 1–5, diffuse, branches ascending to divaricate; leafy bracts much exceeding axillary corymbs. Spikelets red brown to dark brown, ovoid lanceoloid, 3–6(–7) mm, apex acute; fertile scales several, narrowly ovate, 2.5–3.5 mm, apex narrowly acute; midrib included or short excurrent. Flowers: perianth absent. Fruits 1.3–1.5 mm; body brown to blackish, tumidly lenticular, nearly orbicular, 0.6–1 × 0.6–1 mm, margins distinct, narrow, flowing into base of tubercle; tubercle flat, narrowly triangular, at least 0.5 mm high, base broadly 2-lobed, apex acuminate.

Fruiting summer–fall or all year (south). Moist to wet sands or peats of banks of streams and ditches, pond and lakeshores, depressions in savannas, marshes, often in moist to wet disturbed areas; 0–200 m; Ala., Conn., Del., Fla., Ga., Ind., La., Md., Mass., Mich., Miss., N.J., N.Y., N.C., R.I., S.C., Tex., Va., Wis.; West Indies.