Lemon-scented perennial, 4-8 dm; lvs long-petioled, ovate or deltoid-ovate, coarsely crenate, broadly obtuse to truncate at base, the main ones 4-7 cm, those of the branches much smaller and often cuneate at base; verticils few-fld, axillary to foliage lvs; pedicels 3-5 mm; cal 7-9 mm, the lips two-thirds as long as the tube; cor pale yellow, becoming white or pinkish, 8-15 mm, the lips 3 mm; 2n=32. Native of w. Asia, escaped from cult. and established in much of our range. June-Aug.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
This plant was frequently cultivated by the pioneers because of its medicinal qualities. It has, in some instances, persisted on the sites of pioneer habitations and sometimes escaped, especially to roadsides. I have found it in such places and also on open, wooded hills near the Ohio River.