Flora of North America species comparison

to 45 cm × 0.2–1 mm.

markedly arched, not spirally twisted, not contracted near spikelet, when dry usually with several blunt to acute ridges and sulcate, subterete to slightly compressed, to 2 times as wide as thick, 5–15 cm × 0.5–1 mm, firm to hard;

culm tufts not proximally bulbous.

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

distal leaf sheaths brown to reddish proximally, stramineous to reddish distally, apex sometimes reddish, membranous to papery.

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.

3–6 × 2–4 mm;

proximal scale empty, 2.5–4 mm, 1/2 or more as long as spikelet;

floral scales 4–9 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.

perianth bristles 4–7, very unequal, some shorter than 1/2 of achene, stout and smooth, others equaling or exceeding tubercle, very slender and densely spinulose;

anthers 1–1.5 mm.

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.

medium brown, equilaterally trigonous to compressed trigonous or some biconvex, 1.5–2.1 × 0.9–1.2 mm, beak 0.2–0.3 × 0.3–0.4 mm.

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

0.25–0.5 × 0.15–0.2 mm.

= 10.