Oregano is a woodyperennial plant, growing to 90 cm (35 in) tall, withopposite leaves 1–4 cm (1⁄2–1+1⁄2 in) long. The flowers which can be white, pink or light purple, are3–4 mm (1⁄8–3⁄16 in) long, and produced in erect spikes in summer. It is sometimes calledwild marjoram, while its close relativeO. majorana is known as sweet marjoram. Both are widely used asculinary herbs, especially in Turkish, Greek, Spanish, Italian, Latin, and French cuisine. Oregano is also anornamental plant, with numerouscultivars bred for varying leaf colour, flower colour and habit.
The English word "oregano" is a borrowing of theSpanishorégano, which derives from theLatinorīganum, which itself comes fromClassical Greekὀρίγανον (orī́ganon).[4] The ultimate origin is disputed; some claim it is a compound Greek term that consists ofὄρος (óros) meaning "mountain", andγάνος (gános) meaning "joy", thus, "joy of the mountain"[4] whileThe Oxford English Dictionary states it is "probably a loanword [as] the plant comes from Africa".[5]
Oregano is aperennial,[6][7] although it is grown as anannual in colder climates, as it often does not survive the winter.[8][9]
Inflorescence
It grows to 90 centimetres (35 in) tall and 50 cm (20 in) wide.[10] Theleaves are spade-shaped and olive-green. The flowers are purple, pink or white,[11]4–7 cm (1+1⁄2–2+3⁄4 in) long and grouped in clusters.[10]
Oregano is related to the herbmarjoram, sometimes being referred to as wild marjoram.
Drying of the plant material affects both quantity and distribution of volatile compounds, with methods using higher heat and longer drying times having greater negative impact. A sample of fresh whole plant material found to contain 33 g/kg dry weight (3.1 g/kg wet) decreased to below a third after warm-air convection drying. Much higher concentrations of volatile compounds are achieved towards the end of the growing season.[15]
Many subspecies and strains of oregano have been developed by humans over centuries for their unique flavours or other characteristics. Tastes range from spicy or astringent to more complicated and sweet. Simple oregano sold in garden stores asO. vulgare may have a bland taste and larger, less-dense leaves, and is not considered the best for culinary use, with a taste less remarkable and pungent. It can pollinate other more sophisticated strains, but the offspring are rarely better in quality.
The related speciesOriganum onites (Greece, Turkey) andO. syriacum (West Asia) have similar flavours. A closely related plant is marjoram from Turkey, which differs significantly in taste becausephenolic compounds are missing from its essential oil. Some varieties show a flavour intermediate between oregano and marjoram.
O. v. subsp.gracile(K.Koch) Ietsw. (=O. tyttanthum) has glossy green leaves and pink flowers. It grows well in pots or containers, and is more often grown for added ornamental value than other oregano. The flavor is pungent and spicy.[17] – Central Asia,Iran,India,Turkey,Afghanistan,Pakistan.
O. v. subsp.hirtum(Link) Ietsw. – (Italian oregano, Greek oregano) is a common source of cultivars with a different aroma[17] from those ofO. v. gracile. Growth is vigorous and very hardy, with darker green, slightly hairy foliage. Generally, it is considered the best all-purpose culinary subspecies. –Greece, Balkans, Turkey,Cyprus
'Greek Kaliteri' –O. v. subsp.hirtum strains/landraces, small, hardy, dark, compact, thick, silvery-haired leaves, usually with purple undersides, excellent reputation for flavor and pungency, as well as medicinal uses, strong, archetypal oregano flavor (Greekkaliteri: the best)
'Hot & Spicy' –O. v. subsp.hirtum strain
'Nana' – dwarf cultivar
Cultivars traded as Italian, Sicilian, etc. are usually hardy sweet marjoram (O. ×majoricum), ahybrid between the southernAdriaticO. v. subsp.hirtum and sweet marjoram (O. majorana). They have a reputation for sweet and spicy tones, with little bitterness, and are prized for their flavor and compatibility with various recipes and sauces.
Oregano is planted in early spring, the plants being spaced 30 cm (12 in) apart in fairly dry soil, with full sun. It will grow in a pH range between 6.0 (mildly acidic) and 9.0 (strongly alkaline), with a preferred range between 6.0 and 8.0. It prefers a hot, relatively dry climate, but does well in other environments.[19]
Oregano is aculinary herb, used for the flavour of its leaves, which can be more intense when dried than fresh. It has an earthy, warm, and slightly bitter taste, which can vary in intensity. Good-quality oregano may be strong enough to almost numb the tongue, but cultivars adapted to colder climates may have a lesser flavour. Factors such as climate, season, and soil composition may affect the aromatic oils present, and this effect may be greater than the differences between the various species of plants. Among the chemical compounds contributing to the flavour arecarvacrol,thymol,limonene,pinene,ocimene, andcaryophyllene.[20]
Oregano is the staple herb ofItalian cuisine, most frequently used with roasted, fried, or grilled vegetables, meat, and fish. Oregano combines well with spicy foods popular inSouthern Italy. It is less commonly used in the north of the country, as marjoram is generally preferred. Its popularity in the U.S. began when soldiers returning fromWorld War II brought back with them a taste for the "pizza herb", which had probably been eaten in Southern Italy for centuries.[21]
During the summer, generous amounts of dried oregano are often added as a topping to a tomato and cucumber salad inPortugal, but it can be used to season meat and fish dishes as well. InSpain, apart from seasoning, it is used in preparations of a variety of traditional dishes such asmorcilla (Iberian pig blood sausage) andadobo sauce for fish and meat. The dried and ground leaves are most often used in Greece to add flavour toGreek salad, and is usually added to the lemon-olive oil sauce that accompanies fish or meat grills and casseroles. In Albania, dried oregano is often used to make herbal tea which is especially popular in the northern part of Albania.
Oregano oil has been used infolk medicine over centuries.[17] Oreganoessential oil is extracted from the leaves of the oregano plant. Although oregano or its oil may be used as adietary supplement, there is no clinical evidence to indicate that either has any effect on human health.[17][22]
In 2014, the U.S.Food and Drug Administration (FDA) warned aUtah company,Young Living, that its herbal products, including oregano essential oil, were being promoted to have numerous unproven anti-disease effects, and so were being sold as unauthorized misbrandeddrugs subject to seizure and federal penalties.[23] Similar FDAwarning letters for false advertising and unprovenhealth claims about oregano essential oil products were published in 2017 and 2018.[24][25]
Coleus amboinicus, known as Cuban oregano,orégano poleo ('pennyroyal oregano'),orégano francés ('French oregano'), Mexican mint, Mexican thyme, and many other names, is also of the mint family (Lamiaceae). It has large and somewhatsucculent leaves. Common throughout the tropics, including Latin America, Africa, and Southeast Asia, it is probably of eastern-hemisphere origin.
Lippia graveolens, Mexican oregano, known in Spanish asorégano cimarrón ('wild oregano'), is not in the mint family, but in the relatedvervain family (Verbenaceae). The flavor of Mexican oregano has a stronger savory component instead of the piney hint of rosemary-like flavor in true oregano, and its citrus accent might be more aromatic than in oregano. It is becoming more commonly sold outside of Mexico, especially in the southeastern United States. It is sometimes used as a substitute forepazote leaves.
Hedeoma patens, known in Spanish asorégano chiquito ('small oregano'), is also among the Lamiaceae. It is used as an herb in the Mexican states ofChihuahua andCoahuila.
Poliomintha longiflora, common names: Mexican oregano and rosemary mint, is native to Mexico and also grown and used in the United States.
^Tair, Asma; Weiss, Erika-Krisztina; Palade, Laurentiu Mihai; Loupassaki, Sofia; Makris, Dimitris P.; Ioannou, Efstathia; Roussis, Vassilios; Kefalas, Panagiotis (2014). "Origanum species native to the island of Crete: in vitro antioxidant characteristics and liquid chromatography–mass spectrometry identification of major polyphenolic components".Natural Product Research.28 (16):1284–7.doi:10.1080/14786419.2014.896011.PMID24635145.S2CID42500633.
^"Oregano". MedlinePlus, US National Library of Medicine. 2016. Retrieved7 October 2016.
^LaTonya M. Mitchell (22 September 2014)."Warning Letter: Young Living". Inspections, Compliance, Enforcement, and Criminal Investigations, US Food and Drug Administration. Retrieved7 October 2016.
^Ingrid A. Zambrana (25 July 2017)."Warning Letter: Absonutrix". Inspections, Compliance, Enforcement, and Criminal Investigations, US Food and Drug Administration. Retrieved18 May 2019.
^Kimberly L. McMillan (31 January 2018)."Warning Letter: Long Life Unlimited". Inspections, Compliance, Enforcement, and Criminal Investigations, US Food and Drug Administration. Retrieved18 May 2019.
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