Flora of North America species comparison

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

to 100 cm × (0.8–)1–1.2 mm distally.

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

distal leaf blade much longer than sheath.

blades flat, tip trigonous, channeled in cross section, to 40 cm × 1.5–6(–8) mm;

distal leaf blade much longer than sheath.

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

blade-bearing involucral bracts 1–3, proximally blade, often sheath black, leaflike, longest 1–12 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–)2–10, in subumbels, patent or pendent, ovoid, 10–20 mm in flower, 20–50 mm in fruit;

peduncles 5–60 mm, smooth or scabrous;

scales lanceolate or ovate, 5–10 mm, with prominent midrib fading proximal to tip, apex ± acute;

proximal scales without lateral ribs.

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 or pale yellow brown, 15–30 mm, smooth;

anthers 2–5 mm.

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

black, oblanceoloid, 2–5 mm.