Peppermint is a hybrid mint variety, which is a cross between the watermint and spearmint. It is naturalized from Europe; and now it is largely being cultivated in Indiana, Michigan, Oregon, Washington, and California. It is also called by other names like american mint, brandy mint, lamb mint, lammint.
There has been constant demand for the leaves and flowering tops, and are collected as soon as the flowers begin to open and then carefully dried. The main product derived from this herb is it's oil, which is produced by distillation of the cultivated herb; and is called as peppermint oil.
Peppermint has high in menthol content, and is often used as a flavouring in tea, ice cream, confectionery, chewing gum, and toothpaste. Peppermint is added in some shampoos and soaps, to give the hair a minty scent and to produce a cooling sensation on the skin.
Various medicinal uses and effects of peppermint oil are described in the following article, http://nccam.nih.gov/health/peppermintoil/