Taprooted biennial; stems 3-6 dm, the upper part and infl densely pubescent with short slender hairs 0.3-0.5 mm and conspicuously hirsute with spreading hairs usually 2-3 mm; cauline lvs mostly overtopped by the cymes, orbicular in general outline, 6-15 cm wide at anthesis, truncate or with a broadly V-shaped base, shallowly 5-7-lobed, with obtuse or rounded sinuses; sep separate nearly to the base, densely hirsute, alternating with conspicuous small reflexed appendages; cor lavender or pink-purple, 9-13 mm, the lobes about equaling the tube; stamens and style exsert 1-3 mm; 2n=18. Rich moist woods; s. Ont. to s. Minn., s. to Pa., Tenn., Mo., and e. Kans. May, June. (Decemium a.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.