Flora of North America species comparison

1.5–3 times as wide as thick, 20–100 cm × 0.35–2 mm, firm to hard, wiry, with to 8 subacute ribs, rarely nearly smooth;

some culms arching or decumbent and rooting at tips.

obscurely 3–5-angled to terete, 40–110 cm × (2–)3.6–7.5 mm, soft, not septate-nodulose, internally spongy, transverse septa incomplete;

plants never forming filiform, flaccid culms.

distal leaf sheaths not splitting abaxially, proximally dark red to brown, apex usually reddish.

distal leaf sheaths persistent, membranous, apex acute to long-acuminate, sometimes prolonged into a slender bladelike portion to 6 cm.

ovoid, 5–17 × 2.5–5 mm, apex acute;

spikelets on stolons rudimentary, non-flowering, proliferous when rooting;

proximal scale empty, amplexicaulous, ovate, 2–4 mm;

subproximal scale with flower;

floral scales 20–40, 2–3 per mm of rachilla, stramineous to medium brown, midrib region paler, ovate, 3.5–6 × 2–3 mm, membranous to cartilaginous, apex entire, rounded to subacute.

not proliferous, 12–43 × 3.5–6 mm;

rachilla joints bearing obscure winglike remnants of floral scales;

proximal scale without a flower, amplexicaulous, 3.6–7.5 mm;

floral scales 30–125, 1–3 per mm of rachilla, greenish to pale brown, often with pale to dark brown submarginal band or a subapical darker spot, ovate to oblong, 4.3–5.8 × 2.5–3.3 mm, cartilaginous, often membranous toward margins, margins broadly translucent, membranous, apex rounded to acute.

perianth bristles brown, equaling achene or tubercle, densely spinulose;

anthers brown, 2–2.4 mm.

perianth bristles 6–7, stramineous, margins and spinules reddish to pale brown, stout, flattened, subequal, exceeding achene, 2.5–3.2 mm, coarsely retrorsely spinulose;

anthers reddish brown, 1.5–1.9 mm;

styles 3-fid or sometimes 2-fid.

often very variable within one plant, ovoid to obovoid or obpyriform, 1.5–2.5 × 1–1.2 mm, beak to 1 × 0.6 mm.

pale brown, biconvex, obpyriform, 1.7–2.3 × 1.2–1.5 mm, clearly sculptured at 10–15X, each face with 10–15 rows of transversely elongated cells, often isodiametric at achene base, apex usually constricted to neck 0.5–0.6 mm wide.

when present pale to dark brown, pyramidal, to 0.5 × 0.3 mm.

stramineous, lamelliform to high-pyramidal, 0.8–1.1 × 0.7–0.9 mm.