Flora of North America species comparison

terete or obtusely trigonous, 30–80 cm × 1–5 mm, soft to hard, not septate-nodulose, internally spongy, transverse septa incomplete;

plants never forming filiform, flaccid culms.

terete, 2–15 cm × 0.15–0.3 mm, firm to soft.

distal leaf sheaths persistent, membranous, apex acute to acuminate, often prolonged into a slender awn to 4 mm.

distal leaf sheaths persistent, not splitting, proximally stramineous to reddish, distally green or stramineous to reddish, membranous, apex often red, obtuse to acute, tooth absent.

not proliferous, 14–54 × 3–5.6 mm;

rachilla joints without winglike remnants of floral scales;

proximal scale empty, amplexicaulous, 2.5–4.9 mm;

floral scales 40–180, 2–3 per mm of rachilla, stramineous to pale brown, flanks sometimes minutely dotted reddish, usually with pale to dark brown, reddish, or purplish submarginal band, obovate to suborbicular, widest in middle, 3.4–4.5(–6) × 3–4.8 mm, cartilaginous, membranous toward margins, margins broadly translucent, membranous, apex rounded.

ovoid, 1–4 × 1–2 mm, obtuse to acute;

proximal scale amplexicaulous, apex entire;

subproximal scale with flower;

floral scales spreading in fruit, 5–30, 8 per mm of rachilla, medium to very dark brown, midrib region often pale or greenish, broadly ovate, 1–1.3 × 1 mm, apex rounded, entire, not carinate.

perianth bristles 6–7, medium brown to pale brown or reddish, slender, proximally slightly flattened, subequal to unequal, mostly exceeding achene, 2–3.4 mm, smooth or sometimes finely retrorsely spinulose;

anthers reddish brown, 1.7–2.5 mm;

styles 3-fid.

perianth bristles absent;

stamens 3;

anthers yellow, 0.3 mm;

styles 3-fid.

brown, biconvex, obpyriform, 2.2–2.8 × 1.3–1.9 mm, markedly sculptured at 10–15X, each face with (17–)20–24 rows of isodiametric to slightly transversely elongated cells, apex narrowed to a stout, often pale, spongy region 0.8–1.1 mm wide at base, 1/2–3/4 of achene width.

persistent after scales fall, to dark yellow-orange or brown, broadly obpyriform, trigonous, angles evident, 0.6–0.65 × 0.5–0.55 mm, rugulose at 20–30X, 20 blunt horizontal ridges in each vertical series.

dark brown, lamelliform to pyramidal, 0.1–0.5 × 0.2–0.5 mm.

brown, greatly depressed, rudimentary, 0.05–15 × 0.15–0.3 mm.