Stems simple, erect, 3-6 dm, essentially glabrous; lvs seldom more than 5 pairs, thin, ovate to rhombic-elliptic, 5-11 cm, crenate, broadly rounded to a cuneate base, glabrous or nearly so on both sides; petioles 5-20 mm; raceme commonly solitary, 6-15 cm, or with a pair of much shorter lateral ones as well; lowest pair of fls often subtended by foliage lvs; bracts entire, commonly surpassing the cal; cor 2.5 cm. Woods in the piedmont and mts.; Pa., and O. to N.C. and Tenn. May, June.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.