Flora of North America species comparison

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

(often purplish-tinged) glabrous or sparsely and unevenly hairy, especially near leaf axils and among heads, usually glabrescent.

single.

single or loosely clustered.

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).

usually progressively reduced distally (basal sometimes smaller than proximal or mid leaves); petiolate (petioles shorter than to equaling blades, often clasping);

blades broadly lanceolate or lanceolate to oblanceolate, (5–)10–20+ × 2–4(–5+) cm, bases tapered, margins dentate to denticulate (distal leaves smaller, bractlike).

usually ± 8 or ± 13, sometimes 0;

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

usually ± 13, sometimes fewer;

corolla laminae (10–)15–25 mm.

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

± 13 or ± 21, tips often black or brownish (sometimes with scattered black hairs).

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

of 2–5+ linear to filiform bractlets (lengths to 1/2 phyllaries).

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

nodding, 1–5(–10).

usually glabrous, sometimes hirtellous (mostly on angles).

glabrous.

= 40, 80.

= 40, ca. 175–180.