A Japanese hops is an annual vine that was introduced as a cultivated plant. It has leaves that are ruff to the touch with 5 distinct lobes. Small downward curved prickles on the stems make this vine difficult to handle. It reproduces by seeds dispersed by wind and water. Preferring moist soils, it can form dense stands in floodplains and along stream banks and lakeshores, but can thrive in disturbed areas such as roadsides and urban lots. It can be found in full sun or shade.
In 100 Years of Change in the Distribution of Common Indiana Weeds by William and Edith Overlease (2002) reported that Japanese hops was not recorded in Indiana in 1899 (Coulter’s Catalogue of Indiana Plants); however, in 1940 (Deam’s Flora), Japanese hops was reported in the following 4 counties: Howard, Lake, Tipton, and Whitely. It was also reported in Tippecanoe county however not herbarium specimens were recorded. In 2002, Overlease reported Japanese hops in the following 7 counties: Brown, Daviess, Gibson, Knox, Perry, Randolph, and Vanderburgh. In 2006, a specimen of Japanese hops from Morgan County was identified by P&PDL at Purdue University.