Flora of North America species comparison

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

often spreading or reclining, 2–25 cm × 0.3–1 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.

apex of distal leaf sheath acute to acuminate, tooth sometimes present, to 0.2 mm.

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.

ovoid, 2–7 × 1–4 mm, apex subacute;

proximal scale either with flower or empty, base encircling 1/2 of culm;

floral scales 50–100, 10 per mm of rachilla, orange to purple-brown, ovate, 1–1.5 × 0.8 mm, midrib slightly keeled, apex rounded to acute.

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.

perianth bristles absent;

stamens 2(–3);

anthers yellow, 0.2–0.3 mm;

styles 2-fid or some 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.

0.7–1 × 0.6–0.9 mm.

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

deltoid 0.1–0.2 × 0.25–0.45 mm, 1/3–1/2 as high as wide, 1/8–1/4 as high and 3/4–9/10 as wide as achene.