This robust strict biennial is largely restricted to rocky woods on moist base-rich soils in east-central states; 2n = 18. Southern plants with smaller flowers, less exerted stamens and styles, larger less divided leaf segments, and sparser pubescence have been named var. plummeri Wood (F, W). However, that taxon has not been generally accepted. There is also much variation in flower color across the range; more northern plants (at least from Ill. to W.Va.) tend to be paler lavendar or bluish, rather than purple, as predominates in central Ky. (F, SC, Y; D. Boone, pers. comm.) Seedlings establish during spring on bare ground in partial shade, especially on washed soil near calcareous cliffs; they can also do well along roads through ravines, and the species naturalizes well in urban gardens. Germination occurs mostly from (Aug) Sep to Nov. Flowers are produced by second-year plants from late Apr to mid-May, with the peak averaging about two weeks before purshii but overlapping to a large extent; seeds mature during late May. In wet summers, occasional plants in cultivation can keep flowering into July. Although perhaps generally pleasant-smelling, when flowers age plants can emit an unpleasant smell for some humans, akin to that of "wet gym shoes" (L. Winter, pers. comm.).