Flora of North America species comparison

often arching to decumbent, cylindric, ridged when dry, 0.09–0.65 m × 0.5–1.5 mm.

sharply trigonous, sides concave distally, 0.4–1.5 m × 1.5–5 mm.

3–4, 1(–2) cauline;

sheath fronts not pinnate-fibrillose;

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

4–7, nearly equaling culm;

sheath fronts delicately pinnate-fibrillose;

blades 3–6, erect, the distal mostly longer than sheath, 1–2 mm, wide, proximally thickly V-shaped central region trigonous-channeled to laterally flattened, apically asymmetically laterally flattened-trigonous;

apex often markedly eccentric, glabrous, smooth or angles papillose.

capitate or of 1 spikelet or with 1 or 2 branches to 15 mm;

proximal bract erect, like leaf blades, 5–15 cm.

capitate or 1 spikelet;

proximal bract erect, resembling leaf blade, 3–20 cm.

achenes blackish brown, nearly equilaterally sharply trigonous, ovoid to obovoid, 1.3–1.8 × 1–1.4 mm, with 10–20 mostly sharp ridges;

beak 0.1 mm.

1–4, 7–18 × 3–5 mm;

scales straw-colored to orange-brown or central region greenish, ovate-lanceolate, 4–5 × 2.5 mm, margins entire, smooth or awn sparsely spinulose, sometimes distally ciliolate at 40X, apex acute, mucronate, mucro 0.2–0.5 mm.

perianth absent;

anthers 0.3–0.5 mm;

styles 3-fid.

perianth members 6, brown, bristlelike, equaling to slightly exceeding achene, spinulose;

anthers 2–3 mm;

styles 3-fid.

brown, compressed trigonous, ovoid to obovoid, 3.5–4.5 × 1.7–2 mm;

beak 0.5–1 mm.

achenes trigonous, 2.2–3 mm including stout, tapered beak 0.3 mm, with many obscure to evident horizontal ridges.

= 50.

= 70.