Flora of North America species comparison

sometimes arched, smooth or obscurely 4- or 5-angled or -ridged, terete or slightly compressed, 6–25 cm × 0.15–0.3 mm, soft to firm.

distal leaf sheaths persistent, red proximally, colorless distally, closely sheathing, apex blunt.

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.

ovoid, 2–6 × 1–2 mm, apex acute;

scales 5–15, 5 per mm of rachilla, bright red-brown, midrib region green to stramineous, ovate, 1.5–1.7 × 1 mm, midrib keeled to obscure, apex blunt to acute.

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 absent;

anthers 0.5–1 × 0.2 mm.

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.

with angles plus longitudinal ridges ca. 8–9, obscure to rather prominent, obovoid to obpyriform, much less than 2 times longer than wide, 0.55–0.6 × 0.3–0.4 mm, trabeculae 20–30, rather obscure and crowded.

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.

brownish to whitish, pyramidal to depressed, 0.1–0.15 × 0.1–0.2 mm.

= 10 (Europe).