This is widespread in riparian woods of east-central states, especially where browsing by deer or cattle is absent (Hawke 2011). It also prospers in cultivation on uplands, and native status remains uncertain in a few of the records mapped here. Wild plants appear to be generally diploid, but a few cultivars are triploid (Zale & Jourdan 2015). Diverse color forms are known among cultivars, and these usually have relatively compact inflorescences with larger flowers on average than typical in the wild (e.g. see rhs.org and Hawke, 2011). White-flowered plants are infrequent in the wilds of Ky., but relatively common in cultivation. See also notes under amplifolia. P. paniculata and amplifolia can be distinguished from the triflora-glaberrima-maculata group (Ovatae) as follows (W): leaf margin ciliate-serrulate (versus smooth or scabrid); lateral veins of the leaves readily apparent, these joining to form a connecting vein parallel to the leaf margin (versus less prominant without a distinct continuous connecting submarginal vein).