Flora of North America species comparison

(from tuberous rhizomes) multiple, densely branched distally, puberulent throughout.

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

usually opposite (distal sometimes alternate);

sessile or subsessile;

blades 3-nerved distal to bases, oblanceolate, 20–80 × 5–10(–20) mm, bases cuneate, margins serrate proximally, entire distally, apices acute, faces puberulent (abaxial), glabrous or glabrate (adaxial), 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.

5;

corollas 2–4 mm.

5;

corollas (sometimes with purple throats) 2.5–3 mm.

7–10 in 1–2 series, oblanceolate, 1–3 × 0.2–0.5 mm, apices rounded, abaxial faces puberulent, 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.

1–2 mm;

pappi of 20–30 bristles 2.5–3 mm.

1–1.7 mm;

pappi of 20–30 bristles 3–3.5 mm.

= 20, 30, 40.

= 20.