Flora of North America species comparison

40–120 cm × 0.6–1 mm, smooth or scabrous distally.

20–60 cm × 0.5–0.8 mm, distally smooth.

blades flat, trigonous in cross section distally, to 30 cm × 1.5–4 mm;

distal leaf blade much longer than sheath.

blades trigonous-channeled in cross section, to 30 cm × 1–2 mm;

distal leaf blade 1–4 cm × 1–1.5 mm, shorter than its 3.5–5.5 cm sheath.

blade-bearing involucral bracts 2–5, sometimes brown-tinged proximally, leaflike, longest 4–12 cm.

blade-bearing involucral bracts solitary, similar to distal leaf, blade usually gray or black proximally, 0.6–2 cm.

2–10, usually in dense head, ovoid, 6–10 mm in flower, 10–20 mm in fruit;

peduncles 2–10(–20) mm, scabrid;

scales brown, often with green center, ovate-oblong, 4–5 mm, obscurely ribbed or with 3–5 equally prominent ribs, apex obtuse.

(1–)2–5, in subumbels, narrowly ovoid, 7–10 mm in flower, 15–25 mm in fruit;

peduncles 5–30 mm, scabrous;

scales black or dark gray with black tip, broadly ovate, 3–4 mm, scarious, margins absent or to 0.1 mm wide, 5–9-ribbed, midrib prominent, usually dilated distally, reaching tip, apex obtuse-subacute.

perianth bristles usually 10 or more, brown at least at base, rarely entirely white, 12–18 mm, smooth;

anthers 0.7–1.5 mm.

perianth bristles 10 or more, white, 10–15 mm, smooth;

anthers 1–2.5 mm.

dark brown to black, narrowly obovoid or ellipsoid, 2.5–4 mm.

narrowly obovoid, 1.5–3 mm.