Latin Name: Marrubium vulgare
Known Hazards: None known.
Habitat: Downs, waste places and roadsides.
Edibility Rating: 1 (1-5)
Medicinal Rating: 3 (1-5)
Physical Characteristics: Perennial spreading herb to 80 cm high. Leaves to 7 cm long, margins with rounded teeth; hairs on leaves and stems long and star-shaped. Fruit a burr with backward facing hooks. Seeds about 2mm long, with a roughened surface. Deeply rooted with woody taproot and fibrous lateral roots.
Flowers: Petals white. Flowers all year, mostly summer and autumn.The flowers are hermaphrodite (has both male and female organs) and are pollinated by Bees. The plant is self-fertile. It is noted for attracting wildlife.
Distinguishing features: Distinguished by flowers in dense clusters around the stem above the leaf axils; leaves grey-green, opposite, woolly and aromatic, and stems 4-angled.
Dispersal: Mostly by fruit with hooks that attach to wool, fur, bags and other material. Spread also occurs via waterways.
The leaves are used as a seasoning. Bitter and pungent, they are sometimes used to flavour herb beer or liqueurs. Horehound ale is a fairly well-known drink made from the leaves. A mild pleasantly flavoured tea is made from the fresh or dried leaves, it is a favourite cough remedy.
Antidote; Antiseptic; Antispasmodic; Cholagogue; Diaphoretic; Digestive; Diuretic; Emmenagogue; Expectorant; Hepatic; Stimulant; Tonic. White horehound is a well-known and popular herbal medicine that is often used as a domestic remedy for coughs, colds, wheeziness etc. The herb apparently causes the secretion of a more fluid mucous, readily cleared by coughing. The leaves and young flowering stems are antiseptic, antispasmodic, cholagogue, diaphoretic, digestive, diuretic, emmenagogue, strongly expectorant, hepatic, stimulant and tonic. Horehound is a very valuable pectoral, expectorant and tonic that can be safely used by children as well as adult. It is often made into a syrup or candy in order to disguise its very bitter flavour, though it can also be taken as a tea. As a bitter tonic, it increases the appetite and supports the function of the stomach. It can also act to normalize heart rhythm. The plant is harvested as it comes into flower and can be used fresh or dried. The root is a remedy for the bite of rattlesnakes, it is used in equal portions with Plantago lanceolata or P. major.
Essential; Repellent. An essential oil is obtained from the plant and used as a flavouring in liqueurs. The plant has been used as a cure for cankerworm in trees. No more details are given but it is probably a strong infusion of the flowering shoots, or the essential oil, that is use. The growing plant repels flies.
Notes: A hardy, widespread weed of disturbed areas. Common around sheep camps and stock yards. Unpalatable to stock and with its free seeding habit quickly spreads. Horehound is a weed throughout much of the temperate world. Horehound has been used as an ornamental and for brewing of beer. Biological control agents have been released and are showing promise, especially in higher rainfall areas.