Peppermint (Mentha × piperita, also known as M. balsamea Willd.) is a hybrid mint, a cross between watermint and spearmint. The plant, indigenous to Europe, is now widespread in cultivation throughout all regions of the world. It is found wild occasionally with its parent species.
Peppermint typically occurs in moist habitats, including stream sides and drainage ditches. Being a hybrid, it is usually sterile, producing no seeds and reproducing only vegetatively, spreading by its rhizomes. If placed, it can grow anywhere, with a few exceptions. Outside of its native range, areas where peppermint was formerly grown for oil often have an abundance of feral plants, and it is considered invasive in Australia, the Galápagos Islands, New Zealand, and in the United States. in the Great Lakes region, noted since 1843
Peppermint has a long tradition of medicinal use, with archaeological evidence placing its use at least as far back as ten thousand years ago. Peppermint has a high menthol content, and is often used as tea and for flavouring ice cream, confectionery, chewing gum, and toothpaste. The oil also contains menthone and menthyl esters, particularly menthyl acetate. Dried peppermint typically has 0.3-0.4% of volatile oil containing menthol (7-48%), menthone (20-46%), menthyl acetate (3-10%), menthofuran (1-17%) and 1,8-cineol (3-6%). Peppermint oil also contains small amounts of many additional compounds including limonene, pulegone, eucalyptol, caryophyllene and pinene. It is the oldest and most popular flavour of mint-flavoured confectionery. Peppermint can also be found in some shampoos, soaps and skin care products. Menthol activates cold-sensitive TRPM8 receptors in the skin and mucosal tissues, and is the primary source of the cooling sensation that follows the topical application of peppermint oil. Used in this way, it has been known to help with insomnia. One animal study has suggested that Peppermint may have radioprotective effects in patients undergoing cancer treatment. The aroma of peppermint has been found to enhance memory. As such, it can be administered by instructors to their students before examinations, to aid recall. Peppermint flowers are large nectar producers and honey bees as well as other nectar harvesting organisms forage them heavily. A mild, pleasant varietal honey can be produced if there is a sufficient area of plants.