Marrubium (horehound or hoarhound) is a genus of flowering plants in the family Lamiaceae, native to temperate regions of Europe, North Africa, and Asia as far east as the Xinjiang region of western China. A few species are also naturalized in North and South America. The genus name Marrubium derives from the Hebrew marrob or bitter juice. The common name horehound is of unknown origin, but with the first part 'hore' derived from "hoary", "hairy". The species formerly classified as Marrubium nigrum (Black Horehound) is now placed in the genus Ballota.