Flora of North America species comparison

to 45 cm × 0.2–1 mm.

erect, markedly spirally twisted, markedly obliquely contracted near spikelet, when dry often with to 6 broad, rounded ridges on each side, greatly compressed, 3–4 times as wide as thick, 20–40 cm × 1.5–2.5 mm, firm;

culm tufts not proximally bulbous.

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

distal leaf sheaths stramineous to medium (or dark) brown, papery, apex often dark brown to reddish, broadly obtuse.

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.

6–8 × 2–3 mm;

proximal scale empty, 3–4 mm, shorter than to equaling spikelet;

floral scales 8–10 per spikelet, 3.5–5 × 2 mm.

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.

bristles 0–5, unequal, rudimentary to equaling achene, the shorter stout, smooth or nearly so, the longer slender, densely spinulose.

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.

stramineous to medium brown, thickly trigonous, 1.75–2.75 × 1–1.25 mm;

beak 0.3–0.6 mm.

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

0.25–0.6 × 0.3–0.55 mm.

1.8 –3 mm.

= 10.