Gav~commonswiki, CC BY-SA 3.0 The Dual Nature of Japanese Knotweed By Gayil Nalls Sign up for our monthly newsletter! J apanese Knotweed (Reynoutria japonica), also known as Polygonum cuspidatum and Fallopia japonica, is a robust herbaceous perennial belonging to the buckwheat family, Polygonaceae. Native to China, Japan, and Korea, its stems are harvested as a wild-foraged vegetable in...