Giant Knotweed

Polygonum sachalinensis
Family Name:	Polygonaceae
Class:	B
Other Names:	Sakhalin knotweed
Why is it a noxious weed?	It creates dense colonies that exclude native vegetation and greatly alter natural ecosystems. Established populations are extremely persistent and difficult to eradicate, even very small fragments can form new plants.

More Information:

Visit Washington State Noxious Weed Control Board Here