Found this plant at the back of our site, near a creek, RVing at Table Rock State Park, SC. This is a plant with a long mostly bare stalk and tiers of leaves — six leaves per tier. Leaves form a perfect circle.
your plant is one of the species called Joe-Pye-Weed, named after Mr. Joe Pye. The most prevalent theory holds that it refers to a Colonial-era Native American named Joe Pye, who is said to have used one of the species to cure typhus. Another is that Joe Pye was a nineteenth-century white “Indian theme promoter” who used the root of one of the species to induce sweating in cases of typhus. The earliest use of this name dates to 1810–1820. The scientific name is Eupatorium fistulosum, but some place it in the genus Eutrochium. It is rather common in the state in those creek-side habitats and other moist areas and it has a hollow stem. It is probably our tallest Eupatorium.
I hope that this helps.
Steven Hill, Botanist, SCNPS