Knotweed is a common name for plants in several genera in the Polygonaceae family
Fallopia japonica, the Japanese knotweed, a large herbaceous perennial plant species native to Japan, China and Korea
Research has also been carried out on Mycosphaerella leafspot fungus, which devastates knotweed in its native Japan.
Polygonella, a genus of flowering plants in the knotweed and smartweed family, Polygonaceae.