Cephalanthus occidentalis

Family: Rubiaceae
Common Names: Common Button Bush, Button Bush, Button Willow

Native to USA: AL, AR, AZ, CA, CT, DC, DE, FL, GA, IA, IL, IN, KS, KY, LA, MA, MD, ME, MI, MN, MO, MS, NC, NE NH, NJ, NY, OH, OK, PA, RI, SC, TN, TX, VA, VT, WI, WV
Native to Canada: NB, NS, ON, PE, QC