Here are three invasive plants duking it out at Montreal's Technoparc. The tall grass is Phragmites australis, which sets up shop at the edge of waterways as does the purple loosestrife at the bottom of the photo. In between is golden rod, which is a native plant and which is not really considered invasive in Canada, although in Europe and Asia it is.
Will be interesting to see if one of these species dominates the others. I'd like to think that the goldenrod will triumph, but we'll see.