Flora of North America species comparison

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

erect, 3–6 dm, densely short-hairy when young, not glaucous.

opposite, subsessile;

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

subopposite or whorled (3s), subsessile;

blade oblanceolate or lanceolate to widely obovate, 5–16 mm, margins entire or serrulate, sometimes with 3–7 undulations instead of teeth.

thyrses, glabrous or sticky-hairy.

spikelike racemes, short-hairy.

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 4–7 mm, lobes lanceolate;

corolla brownish yellow, pale yellow, or cream, purple- or reddish brown-lined, 10–15 mm, tube plus distinct throat 7–11 mm, longer than adaxial lip, adaxial lip 4–5 mm;

pollen sacs 0.8–1.1 mm;

staminode glabrous, usually included.