Leonurus cardiaca L.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Fibrous-rooted perennial, the ± clustered stems 4–15 dm, retrorsely short-hairy on the angles (or subglabrous); lvs all cauline, the main ones with palmately cleft and again coarsely toothed blade 5–10 cm, the petiole about as long, the middle and upper gradually reduced and less cleft; fls subsessile; cal-tube firm, 5-angled, 3–4 mm, the lobes about equaling the tube, the 2 lower ones deflexed; cor 8–12 mm, white or pale pink, the upper lip conspicuously white-villous, the tube with a ring of hairs inside; 2n=18. Native of Asia, formerly cult. as a home-remedy, now established as a casual weed over much of the U.S. and adj. Can. June–Aug.
motherwort, lion's tail