I’m thinking at the moment specifically about Calyptocarpus vialis because I made an entry for it and it was flagged as being introduced into Travis County by anthropogenic means. I always thought it was native, so I did some research and found this article, which seems to indicate it is native to Travis County.
http://www.phytoneuron.net/PhytoN-Calyptocarpusvialis.pdf
Looking at the details for this species here, I see a list of places where it’s found and how it was introduced, but I don’t find a listing of where it’s considered to be native. I suspect that feature exists and I simply don’t know how to access it.