Horehound

Horehound, common name for a plant of the mint family, native to Eurasia and naturalized in waste places of the north-eastern United States and Canada. It is a herbaceous perennial growing to a height of about 30 cm (12 in) and bearing greyish-white, hoary leaves. The small white flowers, borne in whorls, have a ten-veined, tubular calyx (set of sepals), an asymmetrical, two-lipped corolla (set of petals), four stamens, and a pistil. The fruit is four small nutlets. The whole plant is dotted with small glands that contain an aromatic oil. The leaves also contain lignin, tannin, and resins. Horehound extract, made from the dried leaves and flowers of the plant, is used as a tonic syrup and in horehound sweets as a cough remedy.

Several other mints are also called horehound. The black horehound has purple flowers and dark green leaves that have a foul odour when crushed. It is native to Europe and naturalized elsewhere in temperate regions.

Scientific classification: The horehound belongs to the family Labiatae; it is classified as Marrubium vulgare. The black horehound is classified as Ballota nigra.