This is a largely Appalachian shrub, restricted to acid infertile soils but ranging from subhydric to subxeric sites. Variation may be significant, sometimes suggesting hybridization (FNA 8, W). In Ky., corollas usually appear during mid-April to mid-May, with white lobes and pink tubes., but they are mostly deep pink in some other parts of the range. Bud scales and leaves are sparsely hairy to glabrous. Reports from Ky. of the related species, R. viscosum (L.) Torr., remain unverified and dubious (Defries 1884b, Gm; see notes in M). That species occurs mostly in Atlantic states, but it is also known from e. Tenn., e. Va., s. W.Va. and perhaps Ohio (Ch, HFG, K, W). The ecology of periclymenoides and other deciduous azaleas remains poorly understood. In shade, these species usually do not flower and they can be much browsed by deer (Fargione et al. 1991, Averill et al. 2017). Low vegetative clonal patches are often seen within woods.