This vigorous annual vine is an aggressive invader of disturbed fertile soils, especially sandy river banks. The first report was by Gunn (1969b) from JEFF. By the 1980s, scandens (as japonicus) had been documented in several counties along the Ohio Rv. upstream of JEFF and along the Big Sandy Rv. (M). During the 1990-2010, it has also become locally abundant along banks of the Kentucky Rv. in the Bluegrass Region (A. Berry, report to KSNPC in 2008). It is much more widespread than colls. indicate. The correct name for this species has become H. scandens instead if H, japonicus after resolution of a nomenclatural issue (W; Flora of China 5: 75). There has been some confusion with lupulus (sensu lato), H. scandens can be distinguished as follows (FNA 3, W): bracts of pistillate flowers spinulose-ciliate (versus smooth-margined); veins on lower surface of leaves armed with rigid, spinulose hairs (versus more or less pubescent with lax, weak hairs); leaves with 3-9 lobes even into inflorescences (versus mostly 1-3 or sometimes 5-7 below inflorescences), and with serrulate margins (versus dentate-serrate); petioles often as long as blades or longer (versus usually shorter).