Distribution: West of the Cascades in Washington; California and scattered localities in eastern U.S.
Habitat: Introduced as an ornamental, escaping in lowland forest understory and disturbed soil in shaded areas.
Origin: Introduced from Eurasia
Conservation Status: Not of concern
Creeping perennial, the stems 2-4 dm. tall, hairy throughout, with a strong odor, and with long, leafy stolons, not rooting at the nodes.
Leaves opposite, narrow to broadly lanceolate, petiolate, prominently veined.
Flowers in whorls at the base of upper leaves; calyx deeply divided, the lobes long and narrow, tapering to a point; corolla yellow, highly irregular, bilabiate, 4-lobed, the upper lip hooded, the lower lip with red-brown streaks; stamens 4, nearly included in the hooded, upper lip.