Flora of North America species comparison

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

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

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.

5;

corollas 3–3.5 mm.

5;

corollas 2–2.5 mm.

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.

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).

in corymbiform arrays.

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

2–3 mm;

pappi of 30–40 bristles 3–4 mm.

1–1.5 mm;

pappi of 15–30 bristles 2–2.5 mm.

= 20, 30.

= 20.