I would say it is NOT D. eximia. The reflexed portion of the petals near the apex of the flower look less than 4-8 mm, the crests on the inner petals are not long enough, and the leaves don't look glaucous enough. In the wild, at least where I have seen it, it grows on shale cliffs and rock outcrops in little pockets of soil in shade to relatively sunny sites.
Aaron Floden
Knoxville, Tennessee