Flora of North America species comparison

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

(from tuberous rhizomes) single, densely branched distally (shoots often develop from lateral buds), puberulent throughout (denser distally).

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.

usually opposite (distal sometimes alternate);

sessile or subsessile;

blades 3-nerved distal to bases, elliptic to oblong, 15–50 × (5–)10–20 mm, bases cuneate, margins entire or serrate (unevenly toothed), apices rounded to acute, faces puberulent (abaxial) or glabrate (adaxial), gland-dotted (both).

9–15;

corollas 2.5–3 mm.

5;

corollas 3–3.5 mm.

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.

8–12 in 2–3 series, oblong to lanceolate, 2.5–5 × 0.5–0.7 mm, apices rounded to acute, abaxial faces puberulent throughout.

in corymbiform arrays.

in corymbiform arrays.

1–1.5 mm;

pappi of 20–30 bristles 2–2.5 mm.

1.8–3 mm;

pappi of 20–35 bristles 3.5–4.5 mm.

= 20.

= 20, 30, 40.