Flora of North America species comparison

2–40 cm × 0.5–1.5(–2) mm.

terete, when dry with to 12 blunt ribs, 20–55 cm × 0.5–1.1 mm, soft to firm, internally mostly hollow with complete transverse septa 2–4 mm apart, evident only on sectioning culm.

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

distal leaf sheaths persistent, not splitting, proximally dark red, distally stramineous or reddish, thinly papery, apex often red to brown, obtuse to subtruncate, slightly callose, tooth present, 0.5–1(–3.7) mm.

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.

lanceoloid, 5–13 × 2–2.5 mm, apex acute to obtuse;

proximal scale amplexicaulous, entire;

subproximal scale empty;

floral scales appressed in fruit, 10–100, 10–12 per mm of rachilla, medium brown to stramineous, midrib regions often greenish, ovate, 1–1.5 × 1 mm, entire, apex rounded to subacute, 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 5–6, pale brown, stout, equaling achene;

stamens 3;

anthers brown, 0.4–0.9 mm;

styles 3-fid or a few 2-fid in the same spikelet.

0.9–1.1(–1.5) × 0.7–1.1 mm.

falling with scales, green or medium or dark brown, obpyriform, compressed-trigonous or some biconvex in same spikelet, angles prominent, 0.6–0.8 × 0.5–0.6 mm, neck short or absent, smooth or very finely reticulate at 20–30X.

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).

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

= 10.