Pycnanthemum virginianum

Pycnanthemum virginianum, the Virginia mountain mint, is an erect, rhizomatous perennial herb of the Lamiaceae, growing 60-120 cm tall in moist meadows, prairies, fens, and stream banks across the northeastern and north-central United States and eastern Canada. The stems are square, wiry, much-branched in the upper part, and somewhat glaucous. Leaves are opposite, narrowly lanceolate to linear, 3-6 cm long, with entire or sparsely toothed margins; the foliage emits a strong mint scent when bruised. Dense flat-topped terminal cymes carry numerous small two-lipped flowers, white with purple spotting on the lower lip, blooming in midsummer to early autumn and visited heavily by bees, wasps, and butterflies. The fruits are four small, smooth nutlets enclosed in the persistent two-lipped calyx.