The leaf serration does look to be more like V. missourica, but so do they look like V. texana on the forestryimages site! I wonder if that is correct, the one with missourica is an education site.
Now, those photos along the country road are probably of a different species! The closest shot shows close serration on the leaves.
On the USDA site V. texana looks a bit sparse.
http://plants.usda.gov/java/pr...
Ha! Are the leaves very hairy underneath?
http://floraofohio.blogspot.co...
I'll see what else I can find tomorrow, it's late.
