Cyperus virens Michaux var. brittonii C. B. Clarke

Herbs, perennial, cespitose, rhizomatous. Culms terete, 40–60(–90)cm, glabrous. Leaves flat, 35–70 cm × 4–9(–12) mm. Inflorescences: heads hemispheric, 10–20 mm diam.; rays 5–9(–14), 3.5–10 cm; 2d order rays 0.5–2 cm; bracts 5–10, ± horizontal, flat, 12–40(–50) cm × 2–7 mm. Spikelets (25–)35–50(–60), ovoid, compressed, (3.5–)5–12(–14) × 2.5–3.5(–4) mm; floral scales 10–32, golden brown to brown, 2-keeled, laterally ribless, narrowly lanceolate, 2–2.2(–3) × 0.8–1.4 mm. Flowers: stamen 1; anthers 1 mm; styles 1 mm; stigmas 0.5 mm. Achenes brown, stipitate, narrowly ellipsoid, 1.5–2 × 0.2–0.4 mm, base swollen, spongy, stipe 0.2 × 0.2–0.3 mm, apex acute, beak slender, 0.2 mm, surfaces puncticulate.

Fruiting summer. Damp grasslands, roadsides, ditches; 0–50 m; Fla., Ga., La., S.C.; West Indies (Bahamas).

The slender achenes with conspicuously swollen bases distinguish Cyperus distinctus from other species of subg. Pycnostachys.