Marrubium vulgare Linn. Labiatae. Horehound.
Europe, Asia and north Africa. This plant affords a popular domestic remedy and seems in this country to be an inmate of the medicinal herb-garden only. In Europe, the leaves are sometimes employed as a condiment. Although a plant of the Old World, it is now naturalized in the New World from Canada to Buenos Aires and Chile, excepting within the tropics. It is figured by Clusius, 1601, and finds mention by many of the botanists of that period. Pliny refers to Marrubium as among medicinal plants in high esteem, and it finds mention by Columella. Albertus Magnus, in the thirteenth century, also refers to its valuable remedial properties in coughs. We may hence believe that, as an herb of domestic medicine, horehound has accompanied emigrants into all the cooler portions of the globe.