Stem 6-12 dm, glabrous to hirsutulous or minutely puberulent, often in narrow strips, the hairs to 0.5 mm, often ±reflexed; lvs lanceolate or lance-ovate to narrowly oblong, 2-5 cm wide, glabrous, or rarely minutely hairy along the midvein beneath; cal 3-8 mm at anthesis; cor violet-purple (sometimes rather pale) outside, pale or white inside, 1.5-3.5 cm, the throat abruptly dilated above the middle; anthers glabrous. Meadows and moist or dry woods; Me. to Mich. and Ill., s. to Ga., Miss., and Ark. (P. calycosus)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.