Flora of North America species comparison

(from short rhizomes) single, densely branched distally, puberulent throughout.

(from short caudices or rhizomes) single, sparsely branched distally, 5–10+ dm, glabrous or glabrate proximally, puberulent distally (among heads).

usually opposite (distal sometimes alternate, lateral buds dormant or producing 1 pair of leaves); simple, sessile or subsessile;

blades ± 3-nerved distal to bases, elliptic to lance-elliptic, (30–)50–70 × 5–25 mm (lengths mostly 2–5 times widths), bases narrowly cuneate, margins usually serrate, apices acute, faces puberulent or villous, densely gland-dotted.

usually opposite (distal sometimes alternate); simple, sessile;

blades pinnately nerved, lanceolate to oblong, 70–150+ × 10–30 mm (lengths mostly 2–5 times widths), bases truncate to somewhat rounded, margins serrate, apices narrowly acute to acuminate, faces glabrate (scattered, fine hairs), gland-dotted.

5;

corollas 2.5–3 mm.

5;

corollas 3–3.5 mm.

7–10 in 2–3 series, elliptic, 1–3 × 0.5–1 mm, apices rounded to acute (not mucronate), abaxial faces puberulent, gland-dotted.

10–15 in 2–3 series, elliptic to oblong, 2–5 × 0.5–1.5 mm, apices rounded to acute (not mucronate), abaxial faces villous to puberulent, gland-dotted.

in corymbiform arrays.

in corymbiform arrays.

1.5–2 mm;

pappi of 30–40 bristles 2.5–3 mm.

2–3 mm;

pappi of 30–40 bristles 3–4 mm.

= 20.

= 20, 30.