Azadirachta indica
Template:Short description Template:Use dmy dates Template:Use American English Template:Cs1 config Template:Speciesbox Azadirachta indica, commonly known as neem, margosa, nimtree or Indian lilac,<ref name=GRIN>Template:GRIN</ref> is a tree in the mahogany family Meliaceae. It is one of the two species in the genus Azadirachta. It is native to the Indian subcontinent and to parts of Southeast Asia, but is naturalized and grown around the world in tropical and subtropical areas. Its fruits and seeds are the source of neem oil. Nim is a Hindustani noun derived from Sanskrit nimba (Template:Lang).<ref>Compact Oxford English Dictionary (2013), Neem, page 679, Third Edition 2008 reprinted with corrections 2013, Oxford University Press.</ref><ref>Henry Yule and A. C. Burnell (1996), Hobson-Jobson, Neem, page 622, The Anglo-Indian Dictionary, Wordsworth Reference. (This work was first published in 1886)</ref><ref>Encarta World English Dictionary (1999), Neem, page 1210, St. Martin's Press, New York.</ref>
Description
Template:More citations needed The neem tree is a fast-growing tree that can reach a height of Template:Convert, and rarely Template:Convert. It is evergreen, shedding many of its leaves during the dry winter months. The branches are wide and spreading. The fairly dense crown is roundish and may reach a diameter of Template:Convert. The opposite, pinnate leaves are Template:Convert long, with 20 to 30 medium to dark green leaflets about Template:Convert long.<ref>Template:Cite web</ref> The terminal leaflet often is missing. The petioles are short.<ref>Template:Cite web</ref>
White and fragrant flowers are arranged in more-or-less drooping axillary panicles which are up to Template:Convert long. The inflorescences, which branch up to the third degree, bear from 250 to 300 flowers. An individual flower is Template:Convert long and Template:Convert wide. Protandrous, bisexual flowers and male flowers exist on the same individual tree.
The fruit is a smooth (glabrous), olive-like drupe which varies in shape from elongate oval to nearly roundish, and when ripe is Template:Convert by Template:Convert. The fruit skin (exocarp) is thin and the bitter-sweet pulp (mesocarp) is yellowish-white and very fibrous. The mesocarp is Template:Convert thick. The white, hard inner shell (endocarp) of the fruit encloses one, rarely two, or three, elongated seeds (kernels) having a brown seed coat.
The neem tree<ref>Template:Cite web</ref> is similar in appearance to its relative, the chinaberry or bakain, Melia azedarach,<ref>Template:Cite book</ref> with which it may be confused. Melia azedarach also has toothed leaflets and similar looking fruit. One difference is that neem leaves are pinnate but chinaberry leaves are twice- and thrice-pinnate.
Taxonomy
The name Azadirachta indica was first published by Adrien-Henri de Jussieu in 1830.<ref name="IPNI_1213180-2">Template:Cite web</ref> In 1753, Carl Linnaeus had described two species, Melia azedarach and Melia azadirachta.<ref name=Linn53>Template:Citation</ref> De Jussieu considered Melia azadirachta to be sufficiently different from Melia azedarach to be placed in a new genus.<ref name=DeJu30>Template:Cite journal p. 221</ref> For both his species, Linnaeus referred to the name 'azedarach',<ref name=Linn53/> which is derived from the French 'azédarac', which in turn is from the Persian 'āzād dirakht' (ازادرخت), meaning 'free or noble tree'.<ref>Template:Cite web</ref> The Persian name of the tree, azad darakhat-e-hind, meaning 'the free tree of India', implies that it is free from disease and insect problems.<ref name="IndianNameReference">Template:Cite book</ref>
Distribution
Azadirachta indica is considered to be native to the Assam region, Pakistan and Bangladesh in the Indian subcontinent and to Cambodia, Laos, Myanmar, Thailand and Vietnam in Indochina. It has been widely introduced elsewhere in tropical and subtropical regions, from South America to Indonesia.<ref name = "1213180-2"/>
Ecology
The neem tree is noted for its drought resistance. Normally, it thrives in areas with sub-arid to sub-humid conditions, with an annual rainfall of Template:Convert. It can grow in regions with an annual rainfall below 400 mm, but in such cases it depends largely on ground water levels. Margosa can grow in many different types of soil, but it thrives best on well-drained deep and sandy soils. It is a typical tropical to subtropical tree and exists at annual mean temperatures of Template:Convert. It can tolerate high to very high temperatures and does not tolerate temperature below Template:Convert. Neem is one of very few shade-giving trees that thrive in drought-prone areas such as the dry coastal, southern districts of India and Pakistan. The trees are not at all delicate about water quality and thrive on the merest trickle of water, whatever the quality. In India and tropical countries where the Indian diaspora has reached, it is very common to see neem trees used for shade lining streets, around temples, schools and other such public buildings or in most people's backyards. In very dry areas, the trees are planted on large tracts of land.
Weed status
Neem is considered a weed in many areas, including some parts of the Middle East, most of Sub-Saharan Africa including West Africa and Indian Ocean states, and some parts of Australia. Its weed potential has not been fully assessed.<ref>Template:Cite book</ref>
In April 2015, A. indica was declared a class B and C weed in the Northern Territory, Australia, meaning its growth and spread must be controlled and plants or propagules are not allowed to be brought into the territory. It is illegal to buy, sell, or transport the plants or seeds. Its declaration as a weed came in response to its invasion of waterways in the "Top End" of the territory.<ref>Template:Citation</ref>
After being introduced into Australia, possibly in the 1940s, A. indica was originally planted in the Northern Territory to provide shade for cattle. Trial plantations were established between the 1960s and 1980s in Darwin, Queensland, and Western Australia, but the Australian neem industry did not prove viable. The tree has now spread into the savanna, particularly around waterways, and naturalised populations exist in several areas.<ref>Template:Citation</ref>
Phytochemicals
Neem fruit, seeds, leaves, stems, and bark contain diverse phytochemicals, some of which were first discovered in azadirachta seed extracts, such as azadirachtin established in the 1960s as an insect antifeedant, growth disruptor, and insecticide.<ref name=drugs/><ref name=bbc.co.uk/> The yield of azadirachtin from crushing 2 kg of seeds is about 5 g.<ref name=drugs/>
In addition to azadirachtin and related limonoids, the seed oil contains glycerides, diverse polyphenols, nimbolide, triterpenes, and beta-sitosterol.<ref name=drugs/><ref name="pubchem">Template:Cite web</ref> The yellow, bitter oil has a garlic-like odor and contains about 2% of limonoid compounds.<ref name=drugs/> The leaves contain quercetin, catechins, carotenes, and vitamin C.<ref name=drugs/>
Uses
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Neem leaves are dried in India and placed in cupboards to prevent insects from eating clothes, and in containers in which rice and wheat are stored.<ref name="bbc.co.uk">Template:Cite news</ref> The flowers are also used in many Indian festivals like Ugadi. See below: #Association with Hindu festivals in India.
Culinary
Template:Unreferenced section The tender shoots and flowers of the neem tree are eaten as a vegetable in India. A soup-like dish called Template:Transliteration (Template:Lang) in Tamil (translated as "margosa flower rasam") made of the flower of neem is prepared in Tamil Nadu. In Bengal, young neem leaves are fried in oil with tiny pieces of aubergine (brinjal). The dish is called nim bēgun bhājā (Template:Lang) and is the first item during a Bengali meal, which acts as an appetizer. It is eaten with rice.
Neem is used in parts of mainland Southeast Asia, particularly in Cambodia, Laos (where it is called kadao [[[:Template:Lang]]]), Thailand (where it is known as sadao [[[:Template:Lang]] Template:IPA or satao Template:Lang Template:IPA]), Myanmar (where it is known as ta.ma [[[:Template:Lang]]]) and Vietnam (where it is known as Template:Lang and is used to cook the salad Template:Lang). Even if lightly cooked, the flavour is quite bitter, and the food is not consumed by all inhabitants of these countries. In Myanmar, young neem leaves and flower buds are boiled with tamarind fruit to soften its bitterness and eaten as a vegetable. Pickled neem leaves are also eaten with tomato and fish paste sauce in Myanmar.
Traditional medicine
Products made from neem trees have been used in the traditional medicine of India for centuries,<ref name="drugs">Template:Cite web</ref> but there is insufficient clinical evidence to indicate any benefits of using neem for medicinal purposes.<ref name=drugs/>
In small children, neem oil is toxic and can lead to death.<ref name=drugs/> Neem may also cause miscarriages, infertility, and low blood sugar.<ref name=drugs/>
In Southern India and the Middle-East, neem twigs are often used as a teeth-cleaning twig.<ref name="dentalmuseum.pacific.edu">Template:Cite web</ref>
Pest and disease control
Neem is used as an insecticide, providing a natural alternative to synthetic pesticides. The active ingredient is azadirachtin.<ref>Template:Cite journal</ref> Neem seeds are ground into powder that is soaked overnight in water and sprayed on the crop. To be effective, it must be applied repeatedly, at least every ten days. In addition to directly killing insects, neem acts as an anti-feedant, repellent, and egg-laying deterrent and thus protects the crop from damage. The insects starve and die within a few days. Neem also suppresses the subsequent hatching of their eggs. Neem-based fertilizers have been effective against southern armyworm. Neem cake may be used as a fertilizer.<ref>Template:Cite web</ref> Silver nanoparticles made from the bark and leaves of A. indica were also highly effective at killing first- and fourth-stage Culex quinquefasciatus mosquito larvae, but they worked less well against the pupae and adult mosquitoes.<ref>Template:Cite journal</ref>
Other uses
- Tree: the neem tree is of great importance for its anti-desertification properties and possibly as a good carbon dioxide sink. It is also used for maintaining soil fertility.<ref name=Schroeder>Template:Cite journal</ref><ref name=puhansynmadhuca>Puhan, Sukumar, et al. "Mahua (Madhuca indica) seed oil: a source of renewable energy in India." (2005).</ref>
- Fertilizer: neem extract is added to fertilizers (urea) as a nitrification inhibitor.<ref>Template:Cite journal</ref>
- Animal feed: Neem leaves can be occasionally used as forage for ruminants and rabbits.<ref>Heuzé V., Tran G., Archimède H., Bastianelli D., Lebas F., 2015. Neem (Azadirachta indica). Feedipedia, a programme by Institut national de la recherche agronomique, CIRAD, AFZ and FAO. Last updated on 2 October 2015</ref>
- Teeth cleaning: neem has traditionally been used as a type of teeth-cleaning twig.<ref name="dentalmuseum.pacific.edu"/>
Genome and transcriptomes
The neem genome and transcriptomes from various organs have been sequenced.<ref name="Neem Fruit Transcriptome">Template:Cite journal</ref><ref name="Neem Genome and Four Transcriptomes">Template:Cite journal</ref><ref name="An Improved Genome Assembly of Azadirachta">Template:Cite journal</ref> Expressed sequence tags were identified by generation of subtractive hybridization libraries of neem fruit, leaf, fruit mesocarp, and fruit endocarp.<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref>
Cultural and social impact
The name Nimai ('born under a neem tree'), of the Bhakti movement Vaishnava saint Chaitanya Mahaprabhu (believed to be an incarnation of Radha Krishna in Gaudiya Vaishnavism and ISKCON) is due to his birth under a neem tree.
In 1995, the European Patent Office (EPO) granted a patent on an anti-fungal product derived from neem to the United States Department of Agriculture and W. R. Grace and Company.<ref name="N000123"/> The Indian government challenged the patent when it was granted, claiming that the process for which the patent had been granted had been in use in India for more than 2,000 years. In 2000, the EPO ruled in India's favour, but W. R. Grace appealed, claiming that prior art about the product had never been published. On 8 March 2005, that appeal was lost and the EPO revoked the Neem patent.<ref name="N000123">Template:Cite news</ref>
Biotechnology
The biopesticide produced by extraction from the tree seeds contains limonoid triterpenes.<ref name=drugs/> Currently, the extraction process has disadvantages, such as contamination with fungi and heterogeneity in the content of limonoids due to genetic, climatic, and geographical variations.<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref> To overcome these problems, production of limonoids from plant cell suspension and hairy root cultures in bioreactors has been studied,<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref> including the development of a two-stage bioreactor process that enhances growth and production of limonoids with cell suspension cultures of A. indica.<ref>Template:Cite journal</ref>
Gallery
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Flowers
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Leaves and flowers
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Unripe fruit
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Fruit drying for oil extraction
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Cleaning teeth by chewing stick
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See also
- Azadirachta excelsa
- Azadirachtin
- Ayurveda
- Arid Forest Research Institute (AFRI)
- Neem cake
- Neem oil
- Babool (brand) of toothpaste
- Teeth cleaning twig (datun)
References
External links
Template:Commons category Template:Wikiquote
- Template:Cite book PDF Copy
- Invasiveness information from Pacific Island Ecosystems at Risk (PIER)
- Neem information from the Hawaiian Ecosystems at Risk project (HEAR)
- Template:Cite book Contains a detailed monograph on Azadirachta indica (Neem; Nimba) as well as a discussion of health benefits and usage in clinical practice.
Template:WestAfricanPlants Template:Medicinal herbs and fungi Template:Taxonbar Template:Authority control