Around here the worst "aggressives" seem to be the Teasel/Dipsacus (brought over from Europe because they were used in wool production or something?), Creeping

Around here the worst "aggressives" seem to be the Teasel/Dipsacus (brought over from Europe because they were used in wool production or something?), Creeping Charlie (also Europeans), and Sumac. There are some native sumacs here but the fact that there are large chunks of sumac monoculture I think that some of the sumac in my area was introduced. I'm in SW Wisconsin these days.