Flora of North America species comparison

erect, 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 wider than thick, 5–35 cm × 0.2–0.5(–1.2) mm, soft to hard;

culm tufts often proximally bulbous (if bulbous then tunicated by papery-fibrous scales).

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 stramineous to brown or reddish proximally, green to stramineous or brown distally, membranous to papery, apex often reddish, subtruncate to 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.

3–8 × 1.5–4 mm;

proximal scale with a flower, seldom empty, 2–5 mm, 1/2 or more as long as spikelet;

floral scales 3–10 per spikelet, 2.5–6 × 1.5–2.5 mm.

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–)3–6, often unequal, rudimentary to equaling tubercle, stout to slender, spinules dense to apparently absent;

anthers 1.5–2.7(–3.5) mm.

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.

stramineous to medium brown or gray-brown, equilaterally trigonous to compressed-trigonous, rarely some biconvex, obpyriform (to obovoid), 1.6–2.3 × 0.7–1.3 mm, beak variable.

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.

rarely absent, 0.3–0.4 × 0.2–0.3 mm.

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