.Stems 3-7 dm, hairy throughout with straight, subulate, ±reflexed hairs 0.1 mm, the same pubescence ±developed on both sides of the narrowly lanceolate or lance-oblong lvs; infl glandular, 1-2.5 dm; cal 2.5-5 mm at anthesis; cor 1.6-2.2 cm, white, marked with fine purple lines in the throat; seeds 0.5-0.7 mm; 2n=16. Dry woods and fields; Me. to Minn., s. to Va. and Ark. Apr.-June. (P. arkansanus)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.