Flora of North America species comparison

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

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

usually opposite (nodes often appearing leafy, lateral buds producing 2+ pairs of leaves);

sessile or subsessile;

blades strongly 3-nerved from bases, lance-elliptic to oblanceolate, 50–120 × 5–20 mm, bases ± cuneate, margins entire proximally, serrate distally, apices acuminate, faces puberulent or villous, gland-dotted.

usually opposite (distal sometimes alternate);

sessile;

blades pinnately nerved, narrowly elliptic, 40–100+ × 5–20 mm, bases cuneate (not perfoliate), margins serrate, apices acute to acuminate, faces puberulent, gland-dotted.

5;

corollas 3–3.5 mm.

9–14;

corollas 3–3.5 mm.

8–10 in 2–3 series, oblong, 1–4 × 0.5–1.5 mm, (bases tapered) apices rounded to acute (not mucronate), abaxial faces pubescent throughout.

10–12 in 2–3 series, elliptic to oblong, 1.5–4 × 0.8–1 mm, apices broadly acute to acute, abaxial faces puberulent, gland-dotted.

in corymbiform arrays.

in corymbiform arrays.

2–3 mm;

pappi of 30–40 bristles 3.5–4 mm.

2–3 mm;

pappi of 20–30 bristles 3–3.5 mm.

= 20, 30, 40.

= 20.