نعنا یا نعناع، گیاهی است از رده دولپهایهای پیوسته گلبرگ که سردسته تیره نعناعیان و از سبزیهای خوراکی است. این گیاه تمام اسانسها و خواص پونه را دارد؛ ولی برگهایش کرک کمتری دارند و بریدگیهای کنار برگهای آن بیشتر از پونه و اسانس آن نیز ملایمتر است. نعناع گیاهی است علفی و پایا. ساقههای آن دونوع خزنده و زیر زمینی میباشند.از میان ریشهها، یک شاخه قائم و برگدار کوچک خارج میشود که برگهای آن متقابل، بیضوی، نوک تیز، دندانه دار و کمی پوشیده از کرک بوده و از تمامی قسمتهای آن بوی معطر و مطبوعی استشمام میشود. ساقهٔ این گیاه چهارگوش و به رنگ قرمز مایل به بنفش یا مایل به ارغوانی است. گلهای آن در ماههای مرداد و شهریور ظاهر میگردند. رنگ گلی یا ارغوانی مایل به بنفش دارند و به تعداد زیاد در مجاور یکدیگر به نحوی مجتمع میرویند. 
نعنا گیاهی است با ریشه هوایی و ساقه های مستقیم و چهارگوش ، و برگ های آن به طول 3 تا 5 سانتی متر ، متقابل ، نیزه ای یا دوکی است ، حاشیه ی آن دارای بریدگی های عمیقی است ، بریدگی های کناره آن نوک تیز است. کرک برگ های نعنا کم است. نعنا سبز معمولادر سرتاسر جهان کشت می شود. این گیاه در نواحی شمال ایران و اطراف تهران به حالت وحشی و پرورشی می روید.
نعنای قرمز گونهای از نعنا است که در لبه رودخانهها و در جریان آبهای ملایم و کمعمق می روید و چون برگهایش قرمزرنگند به این نام خوانده میشود.
خواص دارویی و کاربرد[ویرایش]
این گیاه همه آثار نیرودهنده و بادشکن و خلطآور پونه (گیاه) را داراست.
منتول موجود در نعناع به طور اختصاصی تولید 3 مدیاتور اصلی التهاب توسط منوسیتها را مهار می کند. سنتز لکوترینB4، پروستاکلاندین و اینترلوکین1 توسط منتول مهار میشود. بنابراین در درمان بیماریهای التهابی نظیر آسم برونشیال، کولیت و رینیت آلرژیک بسیار موثر است. از انساج نعنا نوعی کافور قابل تبلور نیز به دست میآورند که مانند کافور معمولی به کار میرود. دمکرده برگ نعنا را برای تقویت و رفع نفخ معده و روده مصرف میکنند.
برگهای خشک و نرم شده نعنا را برای خوشبو کردن ماست و دوغ و سرخشده آن را در روغن که به نام نعنا داغ موسوم است برای خوشبو کردن برخی آشها به کار میرود.
Mentha (also known as mint, from Greek míntha, Linear B mi-ta) is a genus of plants in the family Lamiaceae (mint family). The species are not clearly distinct and estimates of the number of species varies from 13 to 18. Hybridization between some of the species occurs naturally. Many other hybrids, as well as numerous cultivars, are known in cultivation.
Mints are aromatic, almost exclusively perennial, rarely annual, herbs. They have wide-spreading underground and overground stolons and erect, square, branched stems. The leaves are arranged in opposite pairs, from oblong to lanceolate, often downy, and with a serrated margin. Leaf colors range from dark green and gray-green to purple, blue, and sometimes pale yellow. The flowers are white to purple and produced in false whorls called verticillasters. The corolla is two-lipped with four subequal lobes, the upper lobe usually the largest. The fruit is a nutlet, containing one to four seeds.
While the species that make up the Mentha genus are widely distributed and can be found in many environments, most grow best in wet environments and moist soils. Mints will grow 10–120 cm tall and can spread over an indeterminate area. Due to their tendency to spread unchecked, some mints are considered invasive.
The list below includes all of the taxa recognized as species in recent works on Mentha. No author has recognized all of them. As with all biological classifications of plants, this list can go out of date at a moment's notice. Common names are also given for species that have them. Synonyms, along with cultivars and varieties, are given in articles on the species.
Mentha is a member of the tribe Mentheae in the subfamily Nepetoideae. The tribe contains about 65 genera, and relationships within it remain obscure. Authors have disagreed on the circumscription of Mentha. Some authors have excluded M. cervina from the genus. M. cunninghamii has also been excluded by some authors, even in some recent treatments of the genus. In 2004, a molecular phylogenetic study indicated both of these species should be included in Mentha.
The mint genus has a large grouping of recognized hybrids. Synonyms, along with cultivars and varieties where available, are included within the specific species.
All mints thrive near pools of water, lakes, rivers, and cool moist spots in partial shade. In general, mints tolerate a wide range of conditions, and can also be grown in full sun. Mint grows all year round.
They are fast-growing, extending their reach along surfaces through a network of runners. Due to their speedy growth, one plant of each desired mint, along with a little care, will provide more than enough mint for home use. Some mint species are more invasive than others. Even with the less invasive mints, care should be taken when mixing any mint with any other plants, lest the mint take over. To control mints in an open environment, they should be planted in deep, bottomless containers sunk in the ground, or planted above ground in tubs and barrels.
Some mints can be propagated by seed, but growth from seed can be an unreliable method for raising mint for two reasons: mint seeds are highly variable - one might not end up with what one presupposed was planted, and some mint varieties are sterile. It is more effective to take and plant cuttings from the runners of healthy mints.
Harvesting of mint leaves can be done at any time. Fresh leaves should be used immediately or stored up to a few days in plastic bags in a refrigerator. Optionally, leaves can be frozen in ice cube trays. Dried mint leaves should be stored in an airtight container placed in a cool, dark, dry area.
The leaf, fresh or dried, is the culinary source of mint. Fresh mint is usually preferred over dried mint when storage of the mint is not a problem. The leaves have a warm, fresh, aromatic, sweet flavor with a cool aftertaste, and are used in teas, beverages, jellies, syrups, candies, and ice creams. In Middle Eastern cuisine, mint is used on lamb dishes, while in British cuisine and American cuisine, mint sauce and mint jelly are used, respectively.
Mint is a necessary ingredient in Touareg tea, a popular tea in northern African and Arab countries. Alcoholic drinks sometimes feature mint for flavor or garnish, such as the mint julep and the mojito. Crème de menthe is a mint-flavored liqueur used in drinks such as the grasshopper.
Mint essential oil and menthol are extensively used as flavorings in breath fresheners, drinks, antiseptic mouth rinses, toothpaste, chewing gum, desserts, and candies, such as mint (candy) and mint chocolate. The substances that give the mints their characteristic aromas and flavors are menthol (the main aroma of peppermint and Japanese peppermint) and pulegone (in pennyroyal and Corsican mint). The compound primarily responsible for the aroma and flavor of spearmint is L-carvone.
Medicinal and cosmetic
Mint was originally used as a medicinal herb to treat stomachache and chest pains. In Rome, Pliny recommended a wreath of mint for students to wear since it was thought to "exhilarate their minds". During the Middle Ages, powdered mint leaves were used to whiten teeth.
Mint leaves are commonly steeped with water to make tea used as a home remedy to help alleviate stomach pain  and as a sleeping aid. Mint tea is a diuretic. A common use is as an antipruritic, especially in insect bite treatments (often along with camphor). The strong, sharp flavor and scent of mint is sometimes used as a mild decongestant for illnesses such as the common cold. Mint is also used in some shampoo products.
Menthol from mint essential oil (40–90%) is an ingredient of many cosmetics and some perfumes. Menthol and mint essential oil are also much used in medicine as a component of many drugs, and are very popular in aromatherapy. Menthol is also used in cigarettes as an additive, because it blocks out the bitter taste of tobacco and soothes the throat.
Although it is used to treat many symptoms, mint can also cause allergic reactions in some people. Although rare, these can induce painful symptoms, including abdominal cramps and diarrhea, headaches, tingling or numbing around the mouth, nasal congestion, clogging of the sinuses, nausea, etc. It can be a reaction to salicylates or linalol contained in the mint, or to some of the proteins inside the plant. It is possible to have high intolerance to one type of mint such as spearmint, yet have no reaction to other types, such as peppermint and menthol, and the symptoms may get worse over time. Because it is uncommon, the people who suffer from mint allergies can find it hard to deal with it on a daily basis. Most of the problems arise from the need to find special toothpaste or dental products, but can also be reactions to the smell of somebody consuming mint candy or gum in a public or work place. In some cases, it can be a minor disturbance, but sometimes a severe reaction; because it is potent, inhaling the mint can trigger by itself breathing problems, nausea, and dizziness, separately or all together. Depending on whether the allergy is to a protein or some other chemical inside the plant, it may or may not extend to other Lamiaceae.
The American Allergy and Asthma Foundation is claimed to have tracked an increasing amount of mint allergies as with allergies in general.
Room scent and aromatherapy
Known in Greek mythology as the herb of hospitality, one of mint's first known uses in Europe was as a room deodorizer. The herb was strewn across floors to cover the smell of the hard-packed soil. Stepping on the mint helped to spread its scent through the room. Today, it is more commonly used for aromatherapy through the use of essential oils.
Main article: List of mint diseases
Etymology of "mint"
Mint descends from the Latin word mentha, which is rooted in the Greek word minthe, personified in Greek mythology as Minthe, a nymph who was transformed into a mint plant. The word itself probably derives from a now extinct pre-Greek language (see Pre-Greek substrate).
Mint leaves, without a qualifier like 'peppermint' or 'apple mint', generally refers to spearmint leaves.
In Spain and Central and South America, mint is known as hierba buena (literally, "good herb"). In Lusophone countries, especially in Portugal, mint species are popularly known as hortelã. In many Indo-Aryan languages, it is called pudīna.
In common usage, other plants with fragrant leaves may be called "mint", although they are not in the mint family.