The trunk of Neem is relatively short, straight and may reach a diameter of 1.2 m. Its 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 petioles are short. The Neem flowers are white and fragrant and are arranged auxiliary, normally more-or-less drooping panicles which are up to 25 cm long. The inflorescences, which branch up to the third degree, bear 150-250 flowers. An individual flower is 5-6 mm long and 8-11 mm wide. Protandrous, bisexual flowers and male flowers exist on the same individual (polygamous).

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  is thin and the bittersweet pulp  is yellowish-white and very fibrous. The white, hard inner shell  of the fruit encloses one, rarely two or three, elongated seeds  having a brown seed coat.

The neem  tree 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. It can tolerate high to very high temperatures but can’t tolerate temperature below 4 °C  as leaf shedding and death may ensue.

Usages:-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. But in India, from time immemorial the neem 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 anthelmintic, antifungal, antidiabetic, antibacterial, antiviral, anti-infertility, and sedative. It is considered a major component in Ayurvedic medicine and is particularly prescribed for skin disease. 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 preparations.

*Neem oil is used for preparing cosmetics, soap, shampoo, balms and creams, and is useful for skin care such as acne, and keeping skin elasticity.

*The neem tree is of great importance for its anti-desertification properties and possibly as a good carbon dioxide sink.

*Patients suffering from Chicken Pox sleep on neem leaves.

*Neem Gum is used as a bulking agent and for the preparation of special purpose food for those having diabetics.

Horticultural usages:-Neem is a source of environment-friendly biopesti- cides. Among the isolated neem consti- tuents, 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. 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, bees, and ladybugs) hardly accumulate significant concentrations of neem products.

Uses in pest and disease control:- Neem is deemed very effective in the treatment of scabies. It is recommended for those who are sensitive to permethrin, a known insecticide which might be an irritant.  There is also anecdotal evidence of its effectiveness in treating infestations of head lice in humans. It is also very good for treating worms. The oil is also used in sprays against fleas in cats and dogs. The tender shoots and flowers of the neem tree are eaten as a vegetable in India. 

Neem is also used in parts of mainland Southeast Asia, particularly in Cambodia, Thailand, Laos and Vietnam. 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