View source for Peppermint

:''This article is about the herb; the tree [[Agonis flexuosa]] is also commonly known as '''peppermint'''.''
{{Taxobox
| color = lightgreen
| name = Peppermint
| image = Mentha piperita - Pfefferminze.jpg
| image_width = 240px
| image_caption = Peppermint (''Mentha'' x ''piperita'')
| regnum = [[Plant]]ae
| divisio = [[Flowering plant|Magnoliophyta]]
| classis = [[Magnoliopsida]]
| ordo = [[Lamiales]]
| familia = [[Lamiaceae]]
| genus = ''[[Mentha]]''
| hybrid = '''''M. × piperita'''''
| binomial = ''Mentha × piperita''
| binomial_authority = [[Carolus Linnaeus|L.]]
}}

'''Peppermint''' (''Mentha × piperita'') is a [[hybrid]] [[Mentha|mint]], a cross between [[watermint]] (''[[Mentha aquatica]]'') and [[spearmint]] (''[[Mentha spicata]]''). It is native to western, central and southern [[Europe]] from the [[British Isles]] east to southern [[Scandinavia]] and western [[Russia]], south to [[Iberia]], and southeast to the [[Balkans]], being found wild occasionally with its parent species.<ref name=empp>Euro+Med Plantbase Project: [http://ww2.bgbm.org/_EuroPlusMed/PTaxonDetail.asp?NameId=114331&PTRefFk=500000 ''Mentha × piperita'']</ref><ref name=fnwe>Flora of NW Europe: [http://ip30.eti.uva.nl/BIS/flora.php?selected=beschrijving&menuentry=soorten&id=3522 ''Mentha × piperita'']</ref>

==Botany==
[[Image:Mentha-piperita.JPG|thumb|left|Peppermint flowers]]
It was first described by Linnaeus from specimens collected in England; he treated it as a [[species]],<ref name=cl>Linnaeus, C. (1753). ''[[Species Plantarum]]'' 2: 576–577.</ref> but is now universally agreed to be a hybrid.<ref name=harley> Harley, R. M. (1975). ''Mentha'' L. In: Stace, C. A., ed. ''Hybridization and the flora of the British Isles'' page 387.</ref>

It is a [[herbaceous]] rhizomatous [[perennial plant]] growing to 30–90 cm tall, with smooth stems, square in cross section. The [[rhizome]]s are wide-spreading, fleshy, and bear fibrous [[root]]s. The [[leaf|leaves]] are from 4–9 cm long and 1.5–4 cm broad, dark green with reddish veins, and with an acute apex and coarsely toothed margins. The leaves and stems are usually slightly hairy. The [[flower]]s are purple, 6–8 mm long, with a four-lobed corolla about 5 mm diameter; they are produced in whorls (verticillasters) around the stem, forming thick, blunt spikes. Flowering is from mid to late summer. The [[chromosome]] number is variable, with 2n counts of 66, 72, 84, and 120 recorded.<ref name=fnwe/><ref name=blamey>Blamey, M. & Grey-Wilson, C. (1989). ''Flora of Britain and Northern Europe''. ISBN 0-340-40170-2</ref><ref name=rhs>Huxley, A., ed. (1992). ''New RHS Dictionary of Gardening''. Macmillan ISBN 0-333-47494-5.</ref>

==Ecology==
It typically occurs in moist habitats, including streamsides and drainage ditches. It is usually [[infertility|sterile]], producing no [[seed]]s and reproducing only [[vegetative reproduction|vegetatively]], spreading by its rhizomes.<ref name=fnwe/><ref name=blamey/>

==Uses==
[[Image: Koeh-095.jpg|thumb|1887 illustration]]
Peppermint is sometimes regarded as 'the world's oldest medicine', with archaeological evidence placing its use at least as far back as ten thousand years ago.{{Fact|date=October 2007}}

Peppermint has a high [[menthol]] content, and is often used as a flavouring in [[Peppermint tea|tea]], [[ice cream]], [[confectionery]], [[chewing gum]], and [[toothpaste]]. The oil also contains [[menthone]] and menthyl esters. It is the oldest and most popular flavour of mint-flavoured confectionery. Peppermint can also be found in some shampoos and soaps, which give the hair a minty scent and produce a cooling sensation on the skin.

Peppermint, like many spices and herbs, is believed to have medicinal properties when consumed.  It is said that it helps against upset stomachs, inhibits the growth of certain [[bacteria]], and can help soothe and relax muscles when inhaled or applied to the skin. Other health benefits are attributed to the high [[manganese]], [[vitamin C]] and [[vitamin A]] content; as well as trace amounts of various other nutrients such as fibre, [[iron]], [[calcium]], folate, [[potassium]], [[tryptophan]], [[magnesium]], [[omega-3 fatty acids]], [[riboflavin]], and [[copper]]. 

[[Image:Pfefferminze ies.jpg|left|thumb|Freeze-dried leaves]]
In 2007, Italian investigators reported that 75% of the patients in their study who took peppermint  oil capsules for four weeks had a major reduction in [[irritable bowel syndrome]] (IBS) symptoms, compared with just 38% of those who took a placebo pill.<ref>ScienceDirect: [http://dx.doi.org/10.1016/j.dld.2007.02.006 Peppermint oil (Mintoil®) in the treatment of irritable bowel syndrome]</ref>

Similarly, some poorly designed earlier trials found that peppermint oil has the ability to reduce colicky abdominal pain due to IBS with an [[NNT]] (number needed to treat) around 3.1,<ref>Bandolier Journal: [http://www.jr2.ox.ac.uk/bandolier/booth/alternat/AT022.html Peppermint oil for irritable bowel syndrome]</ref> but the oil is an irritant to the stomach in the quantity required and therefore needs wrapping for delayed release in the intestine.  Peppermint relaxes the gastro-oesophageal sphincter, thus promoting belching.

Peppermint flowers are large nectar producers and [[honey bee]]s 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.

Peppermint oil is also an all-natural way to deter ants from being inside and outside the home, though it will need to be reapplied every few days (in sparse amounts) until the ants are fully discouraged. This natural substance seems to work on most species of ant.{{Fact|date=October 2007}}

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 species|invasive]] in [[Australia]], the [[Galápagos Islands]], [[New Zealand]],<ref name=pier>Pacific Island Ecosystems at Risk: [http://www.hear.org/pier/species/mentha_x_piperita.htm ''Mentha x piperita'']</ref> and locally in the [[United States]].<ref name=usda>USDA Plants Profile: [http://plants.usda.gov/java/profile?symbol=MEPI ''Mentha x piperita'']</ref>

In the United States, [[Washington]] ranks number one in production of Peppermint Oil.<ref>State of Washington: [http://www.ofm.wa.gov/databook/resources/nt14.asp Washington's Rank in the Nation's Agriculture]</ref>

===Cultivation===
Peppermint generally thrives in shade and expands quickly by underground rhizomes. If you choose to grow peppermint, it is advisable to plant it in a container, otherwise it can rapidly take over a whole garden. It needs a good water supply, and is ideal for planting in part-sun to shade areas.

The leaves and flowering tops are the usable portion of the plant. They are collected as soon as the flowers begin to open and then are carefully dried. The wild form of the plant is less suitable for this purpose, with cultivated plants having been selected for more and better oil content. Seeds sold at stores labelled peppermint generally will not germinate into true peppermint, but into a particularly poor-scented spearmint plant. The true peppermint might rarely produce seeds, but only by fertilisation from a spearmint plant, and contribute only their own spearmint genes.

===Cultivars===
A number of [[cultivar]]s have been selected for garden use:<ref name=rhs/>
*''Mentha × piperita'' 'Candymint'. Stems reddish.
*''Mentha × piperita'' 'Citrata' (Eau De Cologne Mint). Leaves aromatic, hairless.
*''Mentha × piperita'' 'Crispa'. Leaves wrinkled.
*''Mentha × piperita'' 'Lime Mint'. Foliage lime-scented.
*''Mentha × piperita'' 'Variegata'. Leaves mottled green and pale yellow.

==References==
{{Commons|Mentha × piperita}}
{{reflist}}

== See also ==
* [[Altoids]]
* [[Mint chocolate]]
* [[Peppermint tea]]
{{Herbs & spices}}

[[Category:Lamiaceae]]
[[Category:Herbs]]
[[Category:Medicinal plants]]