Japanese knotweed

Reynoutria japonica, synonyms Fallopia japonica and Polygonum cuspidatum, is a large species of herbaceous perennial plant of the knotweed and buckwheat family Polygonaceae. It is commonly known as Asian knotweed or Japanese knotweed. It is native to East Asia in Japan, China and Korea. In North America and Europe, the species has successfully established itself in numerous habitats and is classified as an invasive species in several countries.