Polygonoideae is a subfamily of plants in the family Polygonaceae. It includes a number of plants that can be highly invasive, such as Japanese knotweed, Reynoutria japonica, and its hybrid with R. sa

Reynoutria is a genus of flowering plants in the Polygonaceae, also known as the knotweed or buckwheat family. The genus is native to eastern China, Eastern Asia and the Russian Far East, although spe