Genus of one species of erect perennial from conifer woods on moist, acidic soil in S.E. US, leaves in basal rosettes, cornflower-like heads single, “very large mid-blue” 12-16"h; z5

Transplanted 2 of 3 from Drive. Described as sky blue they are to my eye aster purple, and therefore did not look good with the other blues in that bed, also seemed to be struggling. Took them a while to get going this summer, but seem to be thriving which may well be because they are planted right on the edge of the bed where the soil is mixed with bark mulch and likely more acidic. Might add the last one still lurking in Drive.