Flora of North America species comparison

arachnose, loosely tomentose, or villous (hairs crisped, jointed), glabrescent.

glabrous or sparsely and unevenly tomentose when young.

single.

usually 1.

progressively reduced distally; ± petiolate;

blades elliptic, lanceolate, linear, oblanceolate, rounded-deltate, or suborbiculate, 6–25 × 1–6 cm, bases ± tapered or truncate to cordate, margins entire or ± dentate (distal leaves sessile, bractlike).

evenly distributed; petiolate;

blades ovate to oblanceolate, 2–10 × 0.5–2(–4) cm, bases tapered, margins lobulate to dentate, ultimate margins often secondarily dentate to denticulate (distal leaves sessile).

usually ± 8 or ± 13, sometimes 0;

corolla laminae 6–15(–20) mm (usually yellow, ochroleucous to white in one variety).

0.

usually ± 13 or ± 21, rarely ± 8, (4–)5–12(–15) mm, tips usually black, sometimes green.

± 21, 4–6 mm, tips usually green, sometimes black.

of 1–5+ linear to filiform bractlets (seldom more than 2 mm).

of 2–4(–6+) bractlets (prominent, black-tipped, lengths about 1/4 phyllaries).

6–20(–40+) in corymbiform arrays (peduncle of terminal head often shorter than others).

8–20 in loose, corymbiform arrays.

usually glabrous, sometimes hirtellous (mostly on angles).

usually sparsely hairy, sometimes nearly glabrous.

= 40, 80.

= 40.