Eupatorium serotinum

Family: Asteraceae
Common Names: Late Boneset, Late-flowering Boneset, Lateflowering Thoroughwort, White Boneset

Native to USA: AL, AR, CT, DC, DE, FL, GA, IA, IL, IN, KS, KY, LA, MA, MD, MI, MN, MO, MS, NC, NE, NJ, NY, OH, OK, PA, RI, SC, TN, TX, VA, WE, WV 
Introduced to Canada: ON

Additional Resources:
Flora of North America