Bohemian Knotweed

Polygonum x bohemica
Family Name:	Polygonaceae
Class:	B
Other Names:
Why is it a noxious weed?	It forms dense colonies that exclude native vegetation and greatly alter natural ecosystems. Established populations are extremely persistent and colonies are extremely difficult to eradicate. It poses a significant threat to riparian areas.

More Information:

Visit Washington State Noxious Weed Control Board Here