Peppermint (Mentha piperita L.)
Family: Lamiaceae

Peppermint was first described in 1753 by Carl Linnaeus from specimens that had been collected in England; he treated it as a species, but it is now universally agreed to be a hybrid, a cross between watermint and spearmint.
It is a herbaceous rhizomatous perennial plant growing to 30–90 cm (12–35 in) tall. The leaves are from 4–9 cm (1.6–3.5 in) long and 1.5–4 cm (0.59–1.57 in) broad, dark green with reddish veins, and with an acute apex and coarsely toothed margins. The leaves and stems are usually slightly fuzzy. The flowers are purple, 6–8 mm (0.24–0.31 in) long, with a four-lobed corolla about 5 mm (0.20 in) diameter. Flowering is from mid to late summer.

Curious historical information. Peppermint is a plant of European origin. This plant has always been held in high esteem in European traditions, especially among the Greeks and Romans. The Greeks scented their homes with peppermint aroma. It was also used in baths and to improve  perfumes. In the Middle Ages, mint was considered a kind magic that was used in potions.
In Japan the refreshing and beneficial smell of mint became so widely acclaimed that it became common for people there to carry with them a smell ball of mint leaf.
The English have been attributed with improving this species because, in their gardens, they were able to produce peppermint plants  more refined and with greater aromas. Today the best quality peppermint it is still considered to be those from England..

Geographic Distribution. The plant, indigenous to Europe and the Middle East, is now widespread and cultivated in many regions of the world.

Habitat. 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.

Chemical composition. Volatile oils (composed mainly of menthol, menthone, and menthylacetate), flavonoids, tocopherols, carotenoids, betaine, choline, azulenes, rosmarinic acid and various minerals (Al, Ca, Cr, Co, P, Fe, Mg, Mn, K, Se, Si, Na, Zn).

Medical uses. Peppermint has a long tradition of use in folk medicine and aromatherapy. Peppermint is commonly thought to soothe or treat symptoms such as nausea, vomiting, abdominal pain, indigestion, irritable bowel, and bloating.
You can drink a hot cup of peppermint tea, use the essential oil in a vaporizer in a room  , and use the oil topically on the chest and throat to help kill germs and ease breathing.. Peppermint also makes a good additive for a foot bath.
Because it has a calming and numbing effect, it has been used to treat headaches, skin irritations and  anxiety associated with depression,

According to the German Commission E monographs, peppermint oil (as well as peppermint leaf) has been used internally as an antispasmodic (upper gastrointestinal tract and bile ducts) and to treat irritable bowel syndrome, catarrh of the respiratory tract, and inflammation of the oral mucosa. Externally, peppermint oil has been used for myalgia and neuralgia. According to Commission E, peppermint oil may also act as a carminative, cholagogue, antibacterial, and secretolytic, and it has a cooling action.