Flora of North America species comparison

2–40 cm × 0.5–1.5(–2) mm.

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

2–4 × 1–2 mm, sometimes absent in deeper water;

proximal scale 1/2 or more of spikelet length;

floral scales 6–10 per spikelet, 1.4–2.7 mm, commonly entirely stramineous, apex rounded to subacute.

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.

perianth bristles 6, stramineous, fairly stout to slender, usually equaling achene to slightly exceeding tubercle, sometimes unequal and some 1/2 of achene, very rarely rudimentary, minutely retrorsely spinulose;

anthers 0.7–1.2 mm.

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.

stramineous, sometimes pale brown, obovoid to obpyriform, thickly trigonous, angles distinct, faces concave to plane, rarely convex, 0.9–1.2 × 0.55–0.75 mm, apex tapered, smooth or faintly rough at 30X.

0.9–1.1(–1.5) × 0.7–1.1 mm.

terminating rhizomes usually markedly J- or horseshoe-shaped, body (apart from apical bud) oblong, 2–2.5(–5) × 0.5–1 mm;

tubers among culm bases straight, narrowly fusiform, 4–5 mm.

0.1–0.2 × 0.15 mm.

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).

= 10 (Europe).

= 10.