Flora of North America species comparison

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

(from short caudices) single or multiple, sparsely branched distally, puberulent throughout.

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.

usually opposite (distal sometimes alternate, spreading or horizontal);

sessile;

blades pinnately nerved, elliptic or lance-ovate to narrowly ovate, 50–100 × 15–40 mm, bases rounded to cuneate (not connate-perfoliate), margins serrate, apices acute, faces puberulent or villous, gland-dotted.

5;

corollas 2–4 mm.

(4–)5;

corollas 3–3.5 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, lanceolate (tapering at tips), 2–6 × 1–1.5 mm, apices acute, not mucronate, abaxial faces puberulent, gland-dotted.

in corymbiform arrays.

in corymbiform arrays.

1–2 mm;

pappi of 20–30 bristles 2.5–3 mm.

2–3 mm;

pappi of 20–50 bristles 3.5–4.5 mm.

= 20, 30, 40.

= 30, 40.