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 25–45 centimetres (10–18 in) tall. The leaves are 2–5 cm (0.8–2.0 in) 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.
The Oxford English Dictionary derives the word from two Old English forms: "hoar" ("white," "light-colored," as in "hoarfrost") and "hune" a word of unknown origin designating a class of herbs or plants. The second element was altered by folk etymology.
Horehound has been mentioned in conjunction with medicinal use dating at least back to the 1st century BC.
Horehound is used to make hard lozenge candies that are considered by folk medicine to aid digestion, soothe sore throats, and relieve inflammation.
It occupies disturbed or overgrazed ground, and is favoured by grazing because it is highly unpalatable to livestock. It may persist in native vegetation that has been grazed.