Flora of North America species comparison

2–40 cm × 0.5–1.5(–2) mm.

erect, ascending or arching, quadrangular, sulcate, 1–13 cm × 0.1–0.3 mm, soft.

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

distal leaf sheaths persistent or disintegrating, red-brown, stramineous, green, or mottled red-brown, translucent, apex narrowly acute.

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.

basal spikelets often present, bisexual; often proliferous, ovoid or ellipsoid, laterally compressed when young, but terete at maturity, 2–7 × 1–2.6 mm, acute;

proximal scale empty, often persistent, amplexicaulous, similar to floral scales;

subproximal scale with a flower;

floral scales spirodistichous (superficially appearing ± spiraled), (4–)10–28, 6–9 per mm of rachilla, pale brown, mottled red-brown to purple, ovate or elliptic, 1.3–2.1 × 0.7–1 mm, membranous, midribs green and red-brown, prominent, apex rounded to obtuse.

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 6, colorless, white, or stramineous, slightly shorter than to equaling achene, spinules retrorse, acute;

stamens 3;

anthers 0.4–0.5 mm;

styles 3-fid.

0.9–1.1(–1.5) × 0.7–1.1 mm.

greenish or pale brown or red-brown, often clearly spotted greenish or red-brown, ellipsoid to obovoid, trigonous (or terete?), angles prominent (keeled), 0.6–0.8 × 0.4–0.5 mm, apex constricted proximal to tubercle, smooth.

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).

red-brown, pyramidal, trigonous, 0.1–0.3 × 0.2–0.4 mm.

= 10.