This is widespread in riparian woods of east-central states. 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). The white-flowered form is infrequent in the wild, 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).