This is a widespread variable northern species (FNA 21), but there are no verified records from adjacent counties to Ky. in Ill., Ind., Ohio, W.Va. or Va. (K; see also SERNEC). The only verified records from Ky. are a 1984 coll. from "seep on bank of the Ohio River" in CAMP (NCU) and a ca. 1900 coll. from "swamps near Louisville" in JEFF (Univ. of Cincinnati). Colls. have not been located to support the other records (K, M); reports from HARL (esp. EKY) and KNOX (KNK) appear to be based on misidentifications. E. maculatum differs from other species in Ky as follows (W): florets 8-22 per head (versus 4-7); terminal inflorescence usually somewhat flat-topped (versus rounded); leaves mostly in whorls of 4-5 (versus 3-7), 6-20 cm long (versus 8-35 cm); stem usually solid (versus solid or hollow), usually speckled with purple or sometimes purplish throughout (versus purple throughout or only at nodes or not at all). W has suggested that plants of Southern Appalachian mountains, in forests on mesic acid soils (which might include any plants from HARL), may be distinct from more northern plants in base-rich wetlands. Similar shifts of habitat may occur within Heracleum maximum, Cirsium muticum and Cypripedium parviflorum. The common name "Joe Pye weed" is based on a real person from Massachusetts, who prescribed its use for various ailments ca. 1800 (Pearce & Pringle 2017)..