This southern Appalachian shrub is variable, and there has been some confusion with calendulaceum, which has a more widespread Appalachian range (Cr, FNA 8, W). R. cumberlandense is often hard to distinguish but differs in its flowers, which tend to be smaller (27-46 mm long versus 30-54 mm), more reddish (versus mostly orange); and usually later flowering in early June to early July, well after leaves have expanded (versus late April to early June with leaf expansion or shortly after). Leaves tend to be shorter (31-81 mm versus 45-91 mm), blunter, less hairy, usually somewhat glaucous below and drying with a blackish hue; R. cumberlandensis usually has shorter stature (up to 2 m versus 4 m), with more rhizome development; 2n = 26 as in most of the genus (versus 52). In Ky. it tends to occur on damper soils, sometimes even along streamhead seeps, but there is much overlap of habitat. The coll. from BOYL (KY) is notable for its disjunction and historical interest: H. Garman, 19 Jun 1892, Junction City. Gm's unverified report of calendulaceum from ADAI is also intriguing.; there is a need to check more old colls at GH, PH, US etc.