Flora of North America species comparison

present or absent, horizontal and long or ascending and caudexlike, 0.3–0.5 mm thick, scales usually evident, without tubers.

subterete, often with to 6 prominent ridges when dry, sulcate, 10–30 cm × 0.3–0.5 mm, firm to rigid, spongy.

terete to angled, sometimes compressed, to 100 cm × 5 mm.

distal leaf sheaths persistent, not splitting, proximally brown, red, or stramineous, distally stramineous, green or reddish, papery, apex sometimes reddish, obtuse, rarely callose, tooth absent.

distal leaf sheaths persistent, rarely disintegrating, membranous to papery.

ovoid, 3–8 × 2–3 mm, apex acute to obtuse;

proximal scale amplexicaulous, entire;

subproximal scale with flower;

floral scales spreading in fruit, 8–30, 4–5 per mm of rachilla, dark brown to blackish, midrib regions often stramineous or greenish, ovate to lanceolate, 2–3 × 1.5 mm, apex entire, acute, often carinate in distal part of spikelet.

to 40 × 7 mm;

floral scales 5–500+ per spikelet.

perianth bristles 3–6, whitish to stramineous, stout to slender, often unequal, from rudimentary to 1/2 of achene length;

stamens 3;

anthers dark yellow to brown, 0.9–1.4 mm;

styles 3-fid.

anthers 0.2–2.5 mm;

styles 2-fid or 3-fid.

falling with scales, stramineous, rarely dark brown, ovoid to obpyriform, slightly to greatly compressed-trigonous, rarely thickly lenticular, angles prominent or abaxial angle obscure, 0.9–1.2 × 0.65–0.8 mm, apex narrowly to broadly truncate, neck short, often compressed more than body, at 20–30X finely rugulose with more than 20 horizontal ridges in a vertical series or reticulate or cancellate.

variously colored, biconvex to trigonous, 0.4–2 mm, smooth to markedly sculptured at 10X.

whitish to brown, pyramidal, lower than wide, often 3-lobed as viewed from the top, 0.1–0.3 × 0.4–0.65 mm.

usually clearly different from achene apex in color, texture, and form, rarely merging with apex.