Plants perennial, often forming large mats; rhizomes 0.25–0.6 mm thick, internodes 1–4 cm, scales 2 mm. Culms sometimes decumbent, in same plant sides variably smooth or with 1 to few acute ridges (often nearly smooth or with 1 ridge on 1 side and several ridges on the other), greatly compressed, usually inrolled when dry, rectangular in cross section, 10–40 cm × 0.3–1.5 mm, 0.2–0.5 mm thick, firm, margins often sharply acute, margins and often 1 or more ridges minutely serrulate at 20–30X. Leaves: distal leaf sheaths persistent, red proximally, colorless or stramineous or whitish distally, slightly inflated, thickly membranous, apex acute. Spikelets ovoid or lanceoloid, 3–9 × 1.5–2.5 mm, apex acute; floral scales 15–30, 6 per mm of rachilla, orange-brown or often stramineous or colorless, midrib region stramineous or greenish, ovate-lanceolate, (2.2–)2.7–3.2 × 1.5 mm, midrib prominent, apex acute. Flowers: perianth bristles absent; anthers 1.1–1.75 mm. Achenes compressed-trigonous, with angles plus longitudinal ridges ca. 9–13, prominent, obovoid, mostly 2 times longer than wide, 0.7–0.9(–1.1) × (0.4–)0.5 mm, trabeculae 30–60, rather obscure and crowded. Tubercles brownish, pyramidal, usually depressed, 0.1–0.15 × 0.2–0.25 mm.
More
Rhizomatous perennial; stems in small tufts, erect, 1–4 dm, flattened, 1–1.5 mm wide; spikelet narrowly ovoid, 4–9 mm; scales 3 mm, imbricate in several rows, lance-ovate, acute or acuminate, somewhat marked with purple-brown, with broad scarious margins and tip; basal scale empty or floriferous; bristles none; style trifid; achene obpyramidal, 0.7–1 mm, pale or gray, with several longitudinal ridges and numerous transverse lines; tubercle conic, a fourth as long. Marshes; Ind. to Alta., s. to La. and Colo.; N.Y.
Home
