Flora of North America species comparison

erect, spreading with age, 5–20 dm, glabrous when young, glaucous.

spreading to erect, 6–25 dm, canescent, rarely glabrous when young.

opposite, subsessile;

blade oblanceolate or lanceolate, 10–40 mm, margins 4–12-toothed.

opposite, on short shoots as axillary clusters on older stems;

blade oblanceolate or lanceolate to narrowly obovate or ovate, 5–20 mm, margins entire or 2-toothed, sometimes relatively small.

thyrses, glabrous or sticky-hairy.

panicles, finely short-hairy and sparsely glandular.

calyx 4–8 mm, lobes lanceolate to ovate;

corolla white or cream, lobes sometimes rose tinged, lined purplish or pinkish, 12–18 mm, tube plus distinct throat 4–8 mm, shorter than adaxial lip, adaxial lip 8–12 mm;

pollen sacs 0.6–0.8 mm;

staminode glabrous, slightly exserted.

calyx 3–9 mm, lobes lanceolate to ovate;

corolla yellow drying blackish, 15–23 mm, tube plus distinct throat 6–10 mm, shorter than adaxial lip, adaxial lip 8–15 mm;

pollen sacs 1.1–1.8 mm;

staminode densely yellow-hairy, exserted.