The mystery plant identified! Ironweed (Vernonia baldwinii).

The mystery plant has been identified. I was reading the latest email from Dave's Garden and there it was. It's called Ironweed (Vernonia baldwinii).  It blooms late summer for us and attracts plenty of butterflies. Its a fast grower and reaches 10 feet in our garden. We see it on the side of the road but it only reaches about 4 to 5 feet without supplemental water.