Flora of North America species comparison

10–15 mm diam.

bluntly trigonous with nearly flat sides throughout to cylindric proximally, obscurely trigonous distally, 1–4 m × 4–10 mm, smooth.

often arching to decumbent, cylindric, ridged when dry, 0.05–0.8 m × 0.5–1 mm.

3–4, basal, ca. 1/6 culm length;

sheath fronts coarsely pinnate-fibrillose;

blades 0–1, dorsiventrally flat, not more than 1/2 sheath length, distal blade to 20 × 2 mm.

3–4, 1 cauline;

sheaths straw-colored to brown and disintegrating to fibers, front translucent and splitting;

blades 1–2, proximally thickly C-shaped in cross section, distally flat, from much shorter to longer than sheath, 1–200+ × 0.2–1 mm, smooth or margins distally spinulose.

3 or more times branched, branches to 21 cm;

proximal bract usually erect, obtusely trigonous to subcylindric-channeled, 1–8 cm, margins often scabridulous.

capitate or 1 spikelet or rarely with 1 or 2 branches to 12 mm;

proximal bract erect, resembling leaf blades, 5–150 mm.

25–150+, solitary and in clusters of 2 or more, 5–11 × 3 mm;

scales orange-brown, brightly lineolate-spotted, broadly oval, 2.5 × 2 mm, margins ciliolate, flanks veinless, apex rounded, notch 0.1–0.2 mm deep, awn not contorted, usually bent outward, 0.3 mm, sparsely scabrous.

achenes blackish brown, plano-convex or usually the adaxial surface longitudinally concave, ovoid to obovoid, 1.3–1.7 × 1.2–1.3 mm, with 15–18 mostly sharp ridges;

beak 0.1 mm.

perianth members 2–4, dark red-brown, thickly strap-shaped or trigonous, equaling achenes, fringed with brownish, soft, blunt hairs;

anthers 1.5 mm;

styles 2-fid.

perianth absent;

anthers 0.4 mm;

styles 2-fid.

dark gray-brown when ripe, unequally biconvex or plano-convex, ovoid to obovoid, 1.8–2.2 × 1.3 mm;

beak 0.2 mm.

achenes thickly trigonous with convex abaxial face, 1.7–2.5 × 1.1–1.6 mm, rugose with rounded ridges;

beak 0.3 mm.

= 68.

= 22.