It's interesting that most of the very noxious weeds we have are imports. The Dyer's Woad we are plagued with was brought here by the pioneers to use as a blue clothing dye. We have Russian Olive here, that was also brought by the pioneers because they could dig young sprouts and wrap them in damp burlap and they would live during the 3 month trek in a wagon. It is everywhere and very trashy in the landscape.