IPM1021, New December 2003
Several obvious and annoying features of this aggressive, sprawling weed make it easy to recognize. The stems are armed with downward pointed prickles that make the plant cantankerous to handle, and the leaves cause dermatitis in sensitive individuals. Leaves of Japanese hops are distinctly 5-lobed, 2 to 4 inches in length and have petioles that are up to 8 inches long. The texture of the leaves is similar to sandpaper. Japanese hops have rather inconspicuous, green flowers, which lack petals and have a waddedpaper appearance.
Another vine weed that could possibly be confused with Japanese hops is burcucumber. Burcucumber also has mostly 5-lobed leaves; however, it has tendrils and Japanese hops do not. Burcucumber does have sticky-hairy stems but does not possess the downward pointing prickles that are characteristic of Japanese hops.
Order publications online at http://extension.missouri.edu/explore/shop/ or call toll-free 800-292-0969.