Eutrochium fistulosum (Eupatorium fistulosum), also called hollow Joe-Pye weed, trumpetweed, or purple thoroughwort, is a North American flowering plant in the sunflower family. It is native to southern Canada and throughout the eastern and south central United States from Maine west to Ontario, Wisconsin, and Missouri and south as far as Florida and Texas. The species name fistulosum refers to the tubular stem; see fistula.