Polygonum cuspidatum is an herbaceous perennial native to Japan. It has been introduced to Europe and North America as an ornamental and is also used to stabilise soil, especially in coastal areas. It requires full sun and is found primarily in moist habitats but also grows in waste places, along roadways and other disturbed areas. Once established, P. cuspidatum forms dense stands that shade and crowd out all other vegetation, displacing native flora and fauna, and the overwintering canes and leaves are slow to decompose.
View ISSG Record: Polygonum cuspidatum Sieb. & Zucc. (=Fallopia japonica (Houtt. Dcne.)