Stems erect, 3-10 dm, glabrous or sparsely hairy; cauline lvs lanceolate to ovate, 5-14 cm, acuminate, tapering to a winged petiole, hairy on both sides; cal-lobes lanceolate, 3-6 mm, rather densely strigose; cor 10-15 mm, the limb slightly longer than the tube; anthers linear, 2.5-3.5 mm. Damp woods; Hudson Bay to n. Mich., n. Wis., and n. Minn., w. to Alas. and Oreg.; ne. Io. June, July.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.