Flora of North America species comparison

not rooting at tips, terete, 10–40 cm, soft to firm, smooth.

distal leaf sheaths proximally brownish or sometimes reddish, distally stramineous to green.

ovoid to oblong-subcylindric, 4–12 × 2–3.5 mm, apex acute to rounded;

proximal scale empty, clasping 1/2 of culm, like floral scales;

subproximal 1 or 2 scales often empty;

floral scales 20–100, 10 per mm of rachilla, entirely stramineous or sometimes red-brown, ovate, (1.5–)2–2.5 × 1.5 mm, apex broadly rounded, entire.

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.

perianth bristles (5–)6(–8), brown, stout, the longer equaling achene or tubercle, retrorsely spinulose;

stamens 3;

anthers brown, 1 mm.

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.

falling with scales, obovoid, angles keeled, 0.8–1 × 0.7–0.8 mm, apex with short neck.

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.

whitish to brown, mammillate to pyramidal, 0.2–0.3 × 0.3–0.35 mm, 1/3 or less as wide as achene.

0.1–0.2 × 0.15 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.

= 10 (Europe).