Flora of North America species comparison

2–40 cm × 0.5–1.5(–2) mm.

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

apex of distal leaf sheath obtuse to acute, tooth to 0.3 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.

lanceoloid to subcylindric or ovoid, 5–10(–20) × 2–3(–4) mm, apex acute (to rounded);

proximal scale empty, encircling ca. 2/3 of culm;

floral scales 25–100(–200), 8–12 per mm of rachilla, orangebrown to stramineous, 2(–2.5) × 1–1.3 mm, midribs mostly keeled, ovate, apex narrowly rounded to subacute.

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.

perianth bristles present or often absent, 5–8, brown, stout, rudimentary to slightly exceeding tubercle;

stamens (2–)3;

anthers brown to yellow, 0.3–0.7(–1) mm;

styles 2–3-fid.

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.

0.9–1.1(–1.5) × 0.7–1.1 mm.

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.

depressed, subdeltoid, 0.1–0.3(–0.4) × 0.6–0.9(–1) mm, 1/10–2/5 as high as wide, 1/4 or less as high as achene, 9/10 as wide as achene, very rarely 2/5 as high as achene (in E. engelmannii var. robusta).

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

= 10.