Plants perennial, mat-forming; rhizomes evident, long, 0.3–1 mm thick, soft to firm, cortex often fugaceous, longer internodes 10–25 mm, scales fugaceous, 5–6 mm, membranous, not fibrous. Culms terete, often with some blunt ridges when dry, (5–)10–60 cm × 0.2–1.5 mm, firm, internally spongy. Leaves: distal leaf sheaths persistent, not splitting, proximally red, distally stramineous to green, often callose, thinly papery to thickly membranous, apex often dark red-brown, obtuse to subacute, tooth absent. Spikelets ovoid to lanceoloid, 5–10 × 2–3(–4) mm, apex acute; proximal scale amplexicaulous, entire; subproximal scale with flower; floral scales often spreading in fruit, 10–20, 3–4 per mm of rachilla, brown to often red-brown, midrib regions mostly stramineous to green, broadly ovate, 3–4 × 1.8–2.5 mm, entire, apex acute to obtuse, often some carinate in distal part of spikelet. Flowers: perianth bristles 0–4(–5), light brown to stramineous, stout, usually unequal, rudimentary to equaling achene; stamens 3; anthers dark yellow to stramineous, 1.2–2 mm; styles 2-fid. Achenes not persistent, dark yellow or medium or dark brown, ellipsoid, obovoid, or obpyriform, biconvex, angles obscure, 1.3–1.8 × 1–1.4 mm, apex rounded, neck absent or short, smooth at 30X, or sometimes finely rugulose at 10–20X with 20 or more horizontal ridges in vertical series. Tubercles brown to whitish, pyramidal, much higher than wide to slightly depressed, sometimes spongy and with vertical rows of depressions, 0.4–0.8 × 0.3–0.8 mm.
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Perennials. Stolons long to short. Culms single or tufted, 10-15 cm tall, ca. 1 mm thick, few ribbed and longitudinally sulcate. Leaf sheaths 2 or 3, basally blood-red and apically yellowish green, 1-4 cm, mouth truncate to slightly obliquely truncate. Spikelet narrowly ovoid, ovoid, or oblong, 3-8 × 1.5-3 mm, 4-10-flowered. Basalmost glume empty, amplexicaul for whole of spikelet base; fertile glumes at first green then becoming brownish at middle and both edges purplish red, laxly imbricate, oblong-ovate to oblong-lanceolate, ca. 4 × 2 mm, margin apically becoming broadly hyaline, apex obtuse. Perianth bristles 4-6, longer than nutlet, slightly curved, outwardly spreading, densely retrorsely spinulose. Stigmas 2. Nutlet at first yellow then becoming brown, obovoid to broadly ovoid, 1.4-1.7 × ca. 1 mm, biconvex, ventral side conspicuously convex and dorsal side slightly convex, sometimes obtusely 3-sided, apex constricted and overlain by style base; persistent style base white, shallowly conic-ovoid, slightly elongate basally, nearly as long as wide, ca. 1/2 as long and ca. 1/2 as wide as nutlet, spongy, apex rounded to obtuse. Fl. and fr. Apr-Aug. 2n = 46, 60-88.
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