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.

Marrubium vulgare (white horehound or common horehound) is a flowering plant in the mint family (Lamiaceae), native to Europe, northern Africa, and southwestern and central Asia. It is also widely naturalized in many places, including most of North and South America. It is a grey-leaved herbaceous perennial plant, and grows to 25 to 45 centimetres tall. The leaves are 25 cm long with a densely crinkled surface, and are covered in downy hairs. The flowers are white, borne in clusters on the upper part of the main stem. Horehound drops are bittersweet hard candies made with sugar and an extract of M. vulgare. They are dark-coloured, dissolve in the mouth, and have a flavour that has been compared to menthol and root beer. Like other products derived from M. vulgare, they are sometimes used as an unproven folk treatment for coughs and other ailments. M.vulgare is used to make beverages such as horehound beer, horehound tea (similar to the Maghrebi mint tea), and the rock and rye cocktail.