mint, in botany, common name for members of the Labiatae, a large family of chiefly annual or perennial herbs. Several species are shrubby or climbing forms or, rarely, small trees. Members of the family are found throughout the world, but the chief center of distribution is the Mediterranean region, where these plants form a dominant part of the vegetation. The Labiatae typically have square stems, paired opposite leaves, and tubular flowers with two lips, the upper divided into two lobes and the lower into three. The leaves sometimes grow in whorls; the flowers may be white or shades of red, blue, or purple.
The family is well known for the aromatic volatile or essential oils in the foliage, which are used in perfumes, flavorings, and medicines. Among the more important essential oils are those derived from sage, lavender, rosemary, patchouli, and the true mints. Many of the commonly used potherbs are from the mint family, e.g., basil, thyme, savory, marjoram, oregano, and the plants mentioned above. As is true of most potherbs and spices, these have a history of medicinal use in domestic remedies. Catnip, pennyroyal, hyssop, self-heal, the horehound of confectionery, and curative teas from such plants as bee balm and yerba buena have been similarly used. Species of the Labiatae are often grown as ornamentals as well as in herb gardens, and in the United States several have escaped cultivation and become naturalized as wildflowers. Types of hyssop, sage, pennyroyal, mint, and lavender are among the prevalent native species.
The true mints belong to the genus Mentha. Commercially the most important species is peppermint ( M. piperita ). The leaves and tops are sometimes dried and utilized for flavoring and in medicine but are chiefly in demand for the oil, distilled out for use as a carminative and stimulant, for its derivative menthol (obtained also from other mints), and for flavoring purposes, especially in chewing gum and candy and as a disguise for disagreeable tastes of drugs. Spearmint ( M. spicata ) is distinguishable from peppermint by the absence of a leafstalk. Its flavor is milder (the aromatic principle is carvone), and it too is used in chewing gum and medicines and is often cultivated in gardens as a flavoring. Both plants are European perennials now naturalized in the United States.
Also useful medicinally and as a source of an essential oil is the pennyroyal. True, or European, pennyroyal ( M. pulegium ) is a prostrate perennial. The species name [Lat., = fleabane] is an herbalist's name given for the plant's supposed property of driving away fleas. The related American pennyroyal ( Hedeoma pulegioides ) is a branching annual; pennyroyal tea was a traditional domestic remedy. Other American species of Hedeoma and similar genera are also called pennyroyal. The mint family is classified in the division Magnoliophyta, class Magnoliopsida, order Lamiales.