This species occurs mostly in damp acid soils of Appalachian regions plus an extension into the central mid-west. Variation needs further attention. Most plants in Ky. are clearly referable to var. (or ssp.) pyramidalis, which has more numerous, crowded, narrower leaves and later flowering (Wherry 1955; F, W). There is DNA-based evidence that var. pyramidalis is derived from hybridization of typical P. maculata and P. glaberrima var. interior (Garner et al. 2022). Some plants mapped here appear at least transitional to the more northern and western var. maculata. The reported ranges of vars. pyramidalis and maculata overlap extensively in Ky., but there has been some confusion. Some plants mapped here lack clear purple spotting on the stems, and have been confused with glaberrima. These appear concentrated in southeastern counties: including HARL, JACK, MCRE and WAYN (EKY). Natural hybrids between glaberrima and maculata have been documented, and sometimes appear similar to carolina (Levin 1963). P. maculata sensu lato is distinguished from the glaberrima-carolina-triflora group as follows (F, W): stems usually with strong red or purple dots (versus green or vaguely purplish), arising from tips of slender elongate rootstock (versus from short decumbent bases); inflorescence subcylindric with short branches (versus corymbose or paniculate with long branches, rounded to flat-topped); calyx lobes shorter than tube (versus nearly or quite as long).