Horseweed

Marestail, which is also known as "Canadian horseweed," or just "horseweed," has moved from field crops to become a plague in landscapes and nurseries. The main reason is that certain biotypes are resistant to glyphosate (e.g. Roundup) as well as a number of other agricultural herbicides. In fact, this native North America plant has become such a problem in Ohio it has been added to the state's noxious weeds list.