A small, annual, minutely viscid-pubescent plant, with rather stiff, much-branched stems, 6 to 20 inches high, the branches spreading or ascending. Leaves oblong or oblong-lanceolate, rather blunt at the apex, narrowed at the base into short petioles, 1 to 3 inches long, the upper leaves smaller. Flowers one-half to three-fourths of an inch long, borne one to three together on two-bracteolate stalks in a paniculate inflorescence. Calyx oblique, very unequally five-lobed, the three upper lobes much longer and more united than the two lower ones. Corolla blue, pinkish or rarely nearly white, the tube shorter than the five-cleft limb, the lobes or segments of the corolla more or less declined. Stamens four, blue or violet, curved and projecting far out of the flower.

In dry or sandy fields, Maine to New York, Ontario and Missouri, south to Florida and Texas. Flowering from July to October.

Memoir 15 N. Y. State Museum

Plate 182

B. Blue Curls; Bastard Pennyroyal   Trichostema diehotomun

B. Blue Curls; Bastard Pennyroyal - Trichostema diehotomun