Distribution
Native to the dry forest areas of the Indo-Pakistan subcontinent and possibly also to Burma (Myanmar). It is widely cultivated, also as a plantation tree, and sometimes occurs naturalized throughout India, Pakistan, Sri Lanka, Thailand and Indonesia. More recently it has also been planted in Peninsular Malaysia and Singapore, the Philippines, Australia, Saudi Arabia, tropical Africa, the Caribbean, Central and South America, and the southern United States.
Observations
A small to medium-sized evergreen to deciduous (drier regions) tree up to 25(-30) m tall, bole usually short, branchless for up to 7.5 m, up to 90 cm in diameter, sometimes fluted; leaves up to 38 cm long, with 4-7 pairs of leaflets, leaflets asymmetrical, lanceolate to ovate, 3.5-10 cm x 1.2-4.0 cm, margin serrate; flowers white; fruit oblong or ovoid-oblong, 1.2-1.8 cm long. Azadirachta indica grows naturally in mixed primary monsoon forest in semi-arid to wet regions, from sea-level up to 700 m altitude. The density of the wood is 720-930 kg/m³ at 12% moisture content. See also the table on wood properties.
Selected Sources
Backer, C.A. & Bakhuizen van den Brink, R.C., 1963-1968. Flora of Java. 3 volumes. Noordhoff, Groningen.
Burkill, I.H., 1966. A dictionary of the economic products of the Malay Peninsula. 2nd edition. Ministry of Agriculture and Co-operative, Kuala Lumpur. Vol. 1 (A-H) pp. 1-1240. Vol. 2 (I-Z) pp. 1241-2444.
Chaisurisri, K., Ponoy, B. & Wasuwanich, P., 1986. Storage of Azadirachta indica A. Juss. seeds. The Embryon 2(1): 19-27.
Chudnoff, M., 1980. Tropical timbers of the world. Forest Products Laboratory, Forest Service. United States Department of Agriculture, Madison. 831 pp.
Corner, E.J.H., 1988. Wayside trees of Malaya. 3rd edition. 2 volumes. The Malayan Nature Society, Kuala Lumpur. 774 pp.
Flora Malesiana (various editors), 1950-. Kluwer Academic Publishers, Dordrecht, Boston, London.
Jacobs, M., 1961. The generic identity of Melia excelsa jack. Gardens' Bulletin, Singapore 18: 71-75.
Kijkar, S., 1992. Handbook planting stock production of Azadirachta spp. at the ASEAN-Canada Forest Tree Seed Centre. ASEAN-Canada Forest Tree Seed Centre Project, Muak-Lek, Saraburi, Thailand. 20 pp.
Lamprecht, H., 1989. Silviculture in the tropics; tropical forest ecosystems and their tree species, possibilities and methods for their long-term utilization. Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) GmbH, Eschborn. 296 pp.
Mitra, C.R., 1963. Neem. M.S. Patel, Hyderabad. 190 pp.
National Academy of Sciences, 1980. Firewood crops. Shrub and tree species for firewood production. National Academy Press, Washington D.C. 237 pp.
Pari, G. & Lestari, S.B., 1990. Analisis kimia beberapa jenis kayu Indonesia [Chemical analysis of several Indonesian timbers]. Jurnal Penelitian Hasil Hutan 7(3): 96-100.
Ponnuswamy, A.S., Vinaya Rai, R.S., Surendan, C. & Karivaratharaju, T.V., 1991. Studies on maintaining seed longevity and the effect of fruit grades in neem (Azadirachta indica). Journal of Tropical Forest Science 3(3): 285-290.
Roederer, Y. & Bellefontaine, R., 1989. Can neem seeds be expected to keep their germinative capacity for several years after collection? Forest Genetic Resources Information No 17. FAO, Rome. pp. 30-33.
Ruskin, F.R., 1992. Neem: a tree for solving global problems. National Academy Press, Washington D.C. 141 pp.
Tewari, D.N., 1992. Monograph on neem (Azadirachta indica A. Juss.). R.P. Singh Gahlot for International Book Distributors, Dehra Dun. 279 pp.
Troup, R.S., 1921. Silviculture of Indian trees. 3 volumes. Clarendon Press, Oxford.