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, sparsely branched distally, densely puberulent to pilose 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); simple, sessile or subsessile;

blades ± 3-nerved (distal to bases), elliptic, lanceolate, or lance-ovate, 30–90 × 20–45 mm (lengths mostly 2–2.5 times widths), bases rounded to rounded-cuneate, margins unevenly serrate, apices acute to attenuate, faces puberulent, gland-dotted.

5;

corollas 3–3.5 mm.

5;

corollas 3.5–4 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.

7–10 in 2–3 series, oblong to lance-oblong, 2–7 × 1–1.5 mm, apices (sometimes whitish) acuminate to acute, mucronate, abaxial faces puberulent, gland-dotted.

in corymbiform arrays.

in corymbiform arrays.

2–3 mm;

pappi of 30–40 bristles 3.5–4 mm.

3–4 mm;

pappi of 30–50 bristles 4–5 mm.

= 20, 30, 40.

= 20, 30, 40.