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.

3–42 cm × 0.3–0.6 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 often disintegrating, thinly membranous-translucent, inflated distally, often wrinkled, apex blunt.

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.

ellipsoid, 1.5–9 × 1–3.5 mm, apex acute to acuminate;

proximal scale without flower, not amplexicaulous;

floral scales to 65, 5–7 per mm of rachilla, loosely appressed to appressed, elliptic, 1–3 × 0.4–1.6 mm, membranous, apex 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 (0–)5–8, typically 7, white to stramineous, spinules dense to few;

styles 2-fid, rarely 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.

stramineous to green or dark brown, biconvex, rarely trigonous, obovoid to obpryiform, 0.4–1.1 × 0.3–0.8 mm, very finely reticulate at 40X.

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

whitish to stramineous or green, 0.2–0.7 × 0.2–0.4 mm, apex acute to acuminate.