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.[1][2][3][4]
Marrubium vulgare L. – White horehound or common horehound – widespread from Denmark + Azores + Canary Islands east to Xingiang; naturalized in New Zealand, New Caledonia, Hawaii, Easter Island, North + South America
The genus name Marrubium derives from the Latin word marrubii, meaning horehound. The French Talmudic exegete, Rashi, thinks that this herb may have been used as one of the bitter herbs on the night of Passover.[5] The common English 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.