Envoy at 07:41, 16 October 2007

2007-10-16T07:41:12Z

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'''Neem''' ('''''Azadirachta indica''''', [[synonymy|syn.]] ''Melia azadirachta'' L., ''Antelaea azadirachta'' (L.) Adelb.) is a [[tree]] in the mahogany family [[Meliaceae]]. It is one of two species in the genus '''''[[Azadirachta]]''''', and is native to [[Burma]], [[Nigeria]], [[India]] and [[Pakistan]], growing in [[tropical]] and semi-tropical regions. Other vernacular names include ''Azad Dirakht'' ([[Persian language|Persian]]), DogonYaro ([[Nigerian]]), Margosa, Neeb ([[Arabic language|Arabic]]), Nimtree, Nimba ([[Sanskrit]]), Vepu, Vempu, Vepa ([[Telugu language|Telugu]]), Bevu in [[Kannada language|Kannada]], Veppam in ([[Tamil language|Tamil]]) and Indian-lilac. In East Africa it is also known as ''Mwarobaini'' ([[Kiswahili]]), what means: ''the tree of the 40''. It is said, that it treats 40 different diseases.

Neem is a fast-growing [[tree]] that can reach a height of 15-20 m, rarely to 35-40 m. It is [[evergreen]] but under severe drought it may shed most or nearly all of its leaves. The branches are wide spread. The fairly dense crown is roundish or oval and may reach the diameter of 15-20 m in old, free-standing specimens.

[[Image:3 products.jpg|thumb|150px|left]]
The trunk is relatively short, straight and may reach a diameter of 1.2 m. The bark is hard, fissured or scaly, and whitish-grey to reddish-brown. The sapwood is greyish-white and the heartwood reddish when first exposed to the air becoming reddish-brown after exposure. The root system consists of a strong taproot and well developed lateral roots.

The alternate, [[pinnate]] leaves are 20-40 cm long, with 20-31 medium to dark green leaflets about 3-8 cm long. The terminal leaflet is often missing. The [[Petiole (botany)|petiole]]s are short. Very young leaves are reddish to purplish in colour. The shape of mature leaflets is more or less asymmetric and their margins are dentate with the exception of the base of their basiscopal half, which is normally very strongly reduced and cuneate.

The [[flower]]s (white and fragrant) are arranged axillary, normally more-or-less drooping [[panicle]]s which are up to 25 cm long. The [[inflorescence]]s, which branch up to the third degree, bear 150-250 flowers. An individual flower is 5-6 mm long and 8-11 mm wide. [[Protantrism|Protandrous,]] bisexual flowers and male flowers exist on the same individual (polygamous). [[Image:GntNeemTree.jpg|right|thumb|180px|A Neem Blossom at [[Guntur]], [[India]]]]

The [[fruit]] is a glabrous olive-like [[drupe]] which varies in shape from elongate oval to nearly roundish, and when ripe are 1.4-2.8 x 1.0-1.5 cm. The fruit skin (exocarp) is thin and the bitter-sweet pulp (mesocarp) is yellowish-white and very fibrous. The mesocarp is 0.3-0.5 cm thick. The white, hard inner shell (endocarp) of the fruit encloses one, rarely two or three, elongated [[seed]]s (kernels) having a brown seed coat.

Commercial plantations of the trees are not considered profitable. Around 50,000 neem trees have been planted near [[Mecca]] to provide shelter for the [[pilgrims]].<ref>S. Ganguli (2002) [http://www.ias.ac.in/currsci/jun102002/1303.pdf Neem: A therapeutic for all seasons], ''Current Science'', Vol. 82, No. 11, June. pp. 1304</ref>

The neem tree is very similar in appearance to the [[Chinaberry]], all parts of which are extremely poisonous.

*[http://onevillage.org/neemseeds.htm Close up photograph of neem seeds]

[[Image:GntNeemFlowers.jpg|right|thumb|180px|Neem flowers in closeup]]
== 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 between 400 and 1200 mm. It can grow in regions with an annual rainfall below 400 mm, but in such cases it depends largely on the ground water levels. Neem can grow in many different types of [[soil]], but it thrives best on well drained deep and sandy soils (''p''H 6.2-7.0). It is a typical tropical/subtropical tree and exists at annual mean temperatures between 21-32 °C. It can tolerate high to very high temperatures. It does not tolerate temperature below 4 °C (leaf shedding and death may ensue).

== Chemical compounds ==
The active principles of the plant were brought to the attention of [[natural products]] [[scientists]] in [[1942]] when [[Salimuzzaman Siddiqui]], while working at the Scientific and Industrial Research Laboratory at [[Delhi University]], for the first time extracted three bitter compounds from [[neem oil]], which he provisionally named as '''nimbin''', '''nimbinin''', and '''nimbidin''' respectively.<ref>S. Siddiqui (1942), ''Current Science'', vol.11, pp. 278–279</ref>

== Usage ==
In India, the tree is variously known as "Divine Tree", "Heal All", "Nature's Drugstore", "Village Pharmacy" and "Panacea for all diseases". Products made from ''neem'' have proven medicinal properties, being antihelmintic, antifungal, antidiabetic, antibacterial, antiviral and anti-infertility. It is particularly prescribed for skin disease (Puri, 1999).
* Neem twigs are used for brushing teeth in India, Bangladesh and [[Pakistan]]. This practice is perhaps one of the earliest and most effective forms of dental care.
* All parts of the tree (seeds, leaves, flowers and bark) are used for preparing many different medical preparation.
* [[Neem oil]] is used for preparing cosmetics (soap, shampoo, balms and creams). [http://www.ozonebiotech.com/neemoil.html Neem Oil] is useful for skin care such as acne, and keeping skin elasticity.
* Besides its use in traditional Indian medicine the neem tree is of great importance for its anti-desertification properties and possibly as a good carbon dioxide sink.
* Practictioners of traditional Indian medicine recommend that patients suffering from Chicken Pox sleep on neem leaves.
* [http://www.neemgum.com Neem Gum] is used as a bulking agent and for the preparation of special purpose food (those for diabetics).

=== Horticultural usages ===

Neem is a source of environment-friendly [[biopesticides]]. Among the isolated [[Neem#Chemical compounds|neem constituents]], [[limonoids]] (such as [[Azadirachtin]]) are effective in insect growth-regulating activity. The unique feature of neem products is that they do not directly kill the pests, but alter the life-processing behavior in such a manner that the insect can no longer feed, breed or undergo metamorphosis.<ref>[http://www.pakissan.com/english/allabout/horticulture/neem.wonder.tree.shtml Neem The wonder tree]. Retrieved on [[July 19]] [[2007]].</ref> However, this does not mean that the plant extracts are harmful to all insects. Since, to be effective, the product has to be ingested, only the insects that feed on plant tissues succumb. Those that feed on nectar or other insects (such as [[butterflies]], [[bee]]s, and [[ladybug]]s) hardly accumulate significant concentrations of neem products.

=== Uses in pest and disease control ===
Neem is deemed very effective in the treatment of [[scabies]] although only preliminary scientific proof exists which still has to be corroborated, and is recommended for those who are sensitive to [[permethrin]], a known [[insecticide]] which might be an irritant. Also, the scabies mite has yet to become resistant to neem, so in persistent cases neem has been shown to be very effective. There is also anecdotal evidence of its effectiveness in treating infestations of [[head lice]] in humans. It is also very good{{Fact|date=June 2007}} for treating worms (soak the branches and leaves in lukewarm water and then drink it).

The oil is also used in sprays against [[flea|fleas]] in [[cat]]s and [[dog]]s.

===Culinary use===
The tender shoots and flowers of the neem tree are eaten as a [[vegetable]] in India. Neem flowers are very popular for their use in [[Ugadi]] Pachadi (soup-like pickle)<sup>[http://www.sailusfood.com/2006/03/30/ugadi-pachadi-andhra-delicacy-reflecting-different-flavors-of-life/ recipe]</sup> which is made on Ugadi day in South India.

Neem is also used in parts of mainland [[Southeast Asia]], particularly in [[Cambodia]] (where it is known as ''sadao'' or ''sdao''), [[Laos]] (where it is called ''kadao'') and [[Vietnam]] (where it is called ''sầu đâu'').<sup>[http://pwmf.blogspot.com/2005/12/su-u-cambodian-sadao-salad.html recipe]</sup>. Even lightly cooked, the flavour is quite bitter and thus the food is not enjoyed by all inhabitants of these nations, though it is believed to be good for one's health. [[Neem Gum]] is a rich source of protein.

==References==
{{reflist}}

Neem - Revision history

Envoy at 07:41, 16 October 2007