Houghton’s flatsedge

Herbs, perennial, cespitose, bases cormose, rhizomatous. Culms trigonous, 5–50 cm × 0.5–1.5 mm, glabrous. Leaves V-shaped, 12–30 cm × 1–6 mm. Inflorescences: spikes ± globose to broadly ovoid, 8–20 mm wide; rays 1–8 cm; rachis 2–5 mm, glabrous; bracts 3–8, weakly ascending, flat, 3–20 cm × 1–3.5 mm; rachilla deciduous, wingless. Spikelets 3–18, compressed, ovoid to oblong-lanceoloid, 4–15 × 2.6–3.4 mm; floral scales deciduous, 3–18, laterally stramineous to reddish brown, laterally 3–4-ribbed, broadly ovate, 1.8–2.5 × 1.3–1.6 mm, apex with mucro 0.1–0.2 mm. Flowers: anthers 0.5–0.7 mm; styles 0.4–0.6 mm; stigmas 1–1.5 mm. Achenes dark brown, sessile, broadly ellipsoid, 1.5–2 × 1–1.5 mm, apex obtuse, apiculate, surface glabrous, puncticulate, or papillose. 2n = 168, 170, 172.

Fruiting summer. Riverbanks, sand bars, lakeshores, sand dunes, sandy openings in woods, especially among Jack pines; 0–1100 m; Man., Ont., Que.; Ill., Ind., Maine, Md., Mass., Mich., Minn., N.H., N.J., N.Y., Ohio, Pa., Vt., Va., W.Va., Wis.