Eupatorium is a genus of flowering plants in the aster family, Asteraceae, containing from 36 to 60 species depending on the classification system. Most are herbaceous perennial plants growing to 0.5–3 m tall. A few are shrubs. The genus is native to temperate regions of the Northern Hemisphere. Most are commonly called bonesets, thoroughworts or snakeroots. The genus is named for Mithridates Eupator, king of Pontus.