This invasive shrub is abundantly planted (as "winged burning bush") across east-central states, especially in suburban landscapes. It presents a serious long-term problem, and its sale should be banned. However, browsing by deer often appears to reduce its success (Fargione et al 1991; also pers. obs.). In Ky it has become naturalized much more widely than colls. indicate; sight records of SE are mapped here as open dots. There is considerable variation in leaf size and stem winging. Some plants that lack pronounced wings may be referable to var. aptera Regel, which has been treated as a species (K), but their taxonomic status is not unclear. Young plants of alatus can be difficult to distinguish from americanus; their leaves tend to have more abruptly acuminate tips, longer petioles (to ca. 2 mm versus 1 mm), and sharp serrations (versus blunt). Mature plants have branches with distinctive corky ridges or wings.