Flora of North America species comparison

to 45 cm × 0.2–1 mm.

terete, often with a few blunt ridges when dry, 20–50 cm × 0.2–0.7 mm, soft, spongy.

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

distal leaf sheaths persistent, not splitting, proximally red or stramineous, distally green, membranous, apex usually reddish, subtruncate to obtuse, not callose, tooth present, to 0.4 mm.

orbicular to ovoid, 1–9 × 1–4 mm, apex rounded to acute;

proximal scale without flower, not amplexicaulous;

floral scales to 125, 11–14 per mm of rachilla, tightly appressed, dark red-brown to stramineous, ovate to elliptic, 0.8–3 × 0.6–2(–2.3) mm, membranous to cartilaginous, apex rounded to acute.

narrowly lanceoloid, narrowly ovoid, or narrowly cylindric, 4–10 × 1–1.5 mm, apex narrowly acute;

proximal scale amplexicaulous or clasping 3/4 of culm, entire;

subproximal scale empty or with flower;

floral scales spreading in fruit, 20–80, 5–6 per mm of rachilla, orange-brown, midrib regions stramineous, narrowly ovate-lanceolate, 1.5–2 × 0.8 mm, entire, apex acute, not carinate.

perianth bristles (0–)4–8, typically 7, red-brown, rarely whitish, vestigial to much exceeding tubercle, typically equaling achene, spinules few to dense;

styles 2-fid.

perianth bristles 3–6, stramineous, stout, unequal, rudimentary to less than 1/2 achene length;

stamens 3;

anthers stramineous, 0.7–1.4 mm;

styles 3-fid.

brown ripening to black, biconvex, orbicular to obpyriform, 0.5–1.1 × 0.3–0.7 mm, apex rarely constricted proximal to tubercle, very finely reticulate at 40X.

falling with scales, stramineous, ellipsoid, compressed-trigonous, angles prominent (keeled), 0.6–0.65 × 0.4–0.45 mm, base narrowed, neck long, smooth at 40X.

stramineous to whitish, umbonate to subconic, 0.2–0.4 × 0.2–0.5 mm, apex rounded to acute.

brown, pyramidal, as high as wide to greatly depressed, 0.1–0.25 × 0.15–0.2 mm.

= 10.