Flora of North America species comparison

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

(from short caudices) single, branched distally, puberulent throughout (lateral buds often develop fertile and infertile branches).

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 (proximal) or alternate (lateral buds dormant or producing 1 pair of leaves);

sessile;

blades (often pinnately or ternately lobed) or lobes pinnately nerved, linear, 20–80 × 0.5–2.5(–4) mm, bases cuneate, margins entire, apices acuminate, faces puberulent, gland-dotted.

(4–)5;

corollas 4–4.5 mm.

5;

corollas (sometimes with purple throats) 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.

7–10 in 2–3 series, (sometimes purple) elliptic to oblong, 1–3 × 0.5–0.8 mm, (margins hyaline) apices acuminate and mucronate, abaxial faces puberulent (mostly on midveins), usually gland-dotted.

in corymbiform arrays.

in paniculiform arrays.

2.5–3.5 mm;

pappi of 40–50 bristles 3.5–4.5 mm.

1–1.7 mm;

pappi of 20–30 bristles 3–3.5 mm.

= 20.