Flora of North America species comparison

(from short caudices) single, branched distally, glabrous throughout, gland-dotted.

(from short caudices) single, sparsely to densely branched distally, pubescent throughout (sometimes reddish to purplish).

opposite (proximal) or alternate (nodes often appearing leafy by development of leaves on lateral buds without axis elongation); petiolate or sessile;

blades (usually pinnately or ternately lobed) or lobes 1-nerved or pinnately nerved, linear, 20–100 × 0.2–0.5(–1) mm, bases slightly expanded, margins entire, apices rounded to acute, faces sparsely puberulent to glabrate, gland-dotted.

opposite; petiolate (petioles 10–25 mm);

blades ± 3-nerved, lanceolate, 20–90+ × 5–40 mm, bases rounded to slightly oblique, margins entire or serrate, apices acute, faces puberulent, gland-dotted.

5;

corollas 2–2.5 mm.

9–15;

corollas 2.5–3 mm.

6–10 in 1–2 series, lanceolate, 1.5–3 × 0.5–0.7 mm, apices acuminate, mucronate, abaxial faces glabrous or glabrate (not gland-dotted).

8–12 in 1–2 series, elliptic to oblong, 1–3 × 0.5–1 mm, apices slightly rounded to acute, abaxial faces puberulent, gland-dotted.

in paniculiform arrays (branches supporting heads recurved, secund).

in corymbiform arrays.

1–1.5 mm;

pappi of 15–30 bristles 2–2.5 mm.

1–1.5 mm;

pappi of 20–30 bristles 2–2.5 mm.

= 20.

= 20.