Japanese Knotweed

Reynoutria japonica

Japanese knotweed has invaded the eastern United States and southern Canada. In the mountains and in the Piedmont of North Carolina it is most common in open habitat along streams and in floodplains. It disperses mainly as seeds and rhizome fragments through flooding. 

Japanese knotweed forms small shrubs (10’) with smooth hollow stems, reminiscent of bamboo. Its leaves (6” long and 3 – 4” wide) are oval but taper to a point. Small, white flowers grow in spikes in late summer and early fall.  

Fact Sheet: Japanese Knotweed

Photo credit: Leslie Seiger, San Diego Mesa College, Bugwood.org

Photo Credit: Barbara Tokarska-Guzik, University of Silesia