Flora of North America species comparison

2–12(–19) cm × 0.2–0.4 mm.

greatly compressed, 4–10 times wider than thick, often with 1 or 2 sharp ridges on 1 side, (8–)20–35 cm × 0.7–2.3 mm, hard, finely striate, spongy.

distal leaf sheaths firm, distally tightly sheathing, apex acute.

distal leaf sheaths persistent, not splitting, proximally red or stramineous, distally green to stramineous, inflated, papery, apex dark brown, broadly obtuse to subtruncate, callose, tooth absent.

ovoid to ellipsoid, 2–6(–8) × 1–2.5 mm, apex acute;

proximal scale with or without flower, not amplexicaulous;

floral scales to 100, 15–19 per mm of rachilla, often loosely appressed, dark red-brown to stramineous, ovate to elliptic, 0.6–1.3 × 0.3–0.7 mm, membranous, apex rounded to acute.

ovoid, 4–9 × 2.5–4 mm, apex acute;

proximal scale clasping 2/3–3/4 of culm, apex 2-fid;

subproximal scale empty or with a flower;

floral scales spreading in fruit, 30–60, 6–9 per mm of rachilla, medium or pale brown, midrib region often paler, ovate-lanceolate, 2.5–3.5 × 1.5 mm, apex 2-fid, carinate in distal part of spikelet.

perianth bristles (0–)4–6, typically 4, colorless to whitish, vestigial to 1/2 as long as achene, smooth or spinuliferous;

styles 2-fid.

perianth bristles 0(–5), stramineous to pale brown, 1/2 of to equaling achene length;

stamens 3;

anthers orange-brown, 0.7–1.5 mm;

styles 3-fid.

black, obovoid, biconvex, 0.3–0.5 × 0.3–0.4 mm, apex often constricted proximal to tubercle, smooth at 40X.

falling with scales, yellow-brown to medium brown, obovoid to obpyriform, nearly equilaterally trigonous, cross section circular to slightly compressed, angles obscure or evident, 0.9–1.1 × 0.6–0.75, neck usually very short, finely rugulose at 10–30X, 20 or more low, blunt horizontal ridges in vertical series.

stramineous to whitish, umbonate to subconic, 0.1–0.2 × 0.1–0.2 mm, apex acute.

brown, depressed-pyramidal, often rudimentary, 0.1–0.25 × 0.2–0.3 mm.

= 20.