horehound

Horehound, or Marrubium vulgare, is a perennial herb in the mint family (Lamiaceae). Native to Europe, western Asia, and northern Africa, it has become naturalized in other regions. The plant is known for its hoary, hairy leaves and square, branching stems, and it grows to about 30–90 cm tall. In summer, small white flowers appear in the leaf axils.

Leaves are opposite, oblong to oval, with scalloped margins and a woolly texture. The aroma is minty and bitter. The inflorescences are dense clusters formed in the leaf axils.

Horehound occurs in dry, well-drained soils such as grasslands, pastures, roadsides, and disturbed sites. It tolerates drought and poor soils and can spread by seed and creeping roots.

Culinary uses include flavoring candies and beverages; horehound candy remains a traditional confection. In herbal medicine, horehound has been used as an expectorant and cough remedy, though modern evidence of efficacy is limited. Chemically, it contains marrubiin, other diterpenoids, and essential oils that contribute to its aroma and flavor. Concentrated essential oils can irritate skin and mucous membranes; use should be moderate and guided by professionals when used medicinally.

Cultivation is favored in full sun with well-drained soil. It is drought-tolerant and hardy, and can spread by seed or division. It is commonly grown in herb gardens and has naturalized in suitable climates.