Coarse, strong-scented biennial or annual to 1 m, conspicuously villous, especially the stem; lvs large, sessile, 5-20 נ2-14 cm, rather shallowly pinnatilobate, with unequal, triangular segments; mature cal 2.5 cm, urceolate, reticulate-veiny; cor 2.5-4.5 cm, nearly or quite as wide, prominently purple-reticulate on a pale, often greenish-yellow background, more distinctly purple in the throat; fr 1-1.5 cm, with a strongly thickened lid; 2n=34. Native of Europe, now established as a weed of roadsides and waste places in n. U.S. and s. Can., more especially westward. May-Sept. A source of hyoscyamine and scopolamine.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.