Flora of North America species comparison

(from short caudices or stout rhizomes) single, sparsely branched distally, pubescent throughout.

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

usually opposite (distal sometimes alternate);

sessile;

blades ± 3-nerved or pinnately nerved, elliptic to oblanceolate, 30–120 × 10–40 mm (lengths mostly 3–4 times widths), bases narrowly cuneate (sometimes oblique), margins subentire, serrate, or serrulate, apices rounded to acute, faces setulose (denser on midribs and veinlets) to glabrate, usually 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.

(4–)5;

corollas 4–4.5 mm.

9–15;

corollas 2.5–3 mm.

9–15 in 2–4 series, linear, 1.5–9 × 0.6–1 mm, apices acuminate to attenuate, sometimes mucronate, abaxial faces pubescent throughout, 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 corymbiform arrays.

in corymbiform arrays.

2.5–3.5 mm;

pappi of 40–50 bristles 3.5–4.5 mm.

1–1.5 mm;

pappi of 20–30 bristles 2–2.5 mm.

= 20.