Neem is a fast growing tree that usually reaches a height of 15-20 m, and under very favorable conditions up to approximately 30-35 m. As a rule it is a evergreen tree, but under extreme circumstances, such as extended dry periods, it may shed most of nearly all of its leaves. The branches spread widely. The fairly dense crown is roundish or oval and may reach a diameter 15-20 m in old free standing specimens. The trunk is relatively short, straight and may reach a girth of 1.5-3.5 m. The bark is hard fissured or scaly and whitish-gray to reddish-brown. The sap wood is grayish-white and the heart wood reddish.
The root system consists of a strong ta proot and well developed lateral roots. The lateral surface root may reach over 18 m. Vesicular-arbuscular mycorrhiza (VAM) is associated with the rootlets categorized neem as a highly VAM dependant plant species.
The leaves are unpaired, pinnate, 20-30 cm long and the medium to dark green leaflets, which number up to 31, are approximately 3-8 cm long. The terminal leaf is often missing. The petioles are short. The shape of mature leaflets is more or less asymmetric.
Natural hybrids between A. indica and A. Siamensis , found in Thailand on places where both species grow together, have an intermediate position regarding the shape and consistency of the leaflets.
The white, gragrant flowers are arranged in axillary, normally more or less drooping panicles which are up to 25 cm long.
The glabrous fruits are olive- like drupes which vary in shape from elongate ovea to nearly roundish and when ripe are 1.4-2.8 x 1.0-1.5 cm . They are green when young and yellowish-green to yellow, rarely reddish when mature. 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 ‘shell (endocarp) of the seed encloses one, rarely two and very rarely three elongated seed kernels having brown testa.
Neem (Azadirachta indica) is a tree that grows in tropical regions such as India. The leaf extract is used to reduce tooth plaque and to treat lice.
Neem contains chemicals that might help reduce blood sugar levels, heal ulcers in the digestive tract, prevent pregnancy, kill bacteria, and prevent plaque from forming in the mouth.
People use neem for lice, tooth plaque, gingivitis, psoriasis, to repel insects, and for many other purposes, but there is no good scientific evidence to support most of these uses. There is also no good evidence to support using neem for COVID-19. Neem seed oil is used as a pesticide.
Neem leaves have been fed to sheep, goats and cattle to improve their performance. It was concluded that neem leaves can be a useful dry season fodder species in the dryer areas of Ghana where ruminant feeding during the often prolonged dry season is a major challenge.
It has many uses, most notably as a pesticide. It repels and kills bugs. The difference between the oil and the pesticides well-known for their chemical composition, is that neem is completely natural and generally safe for dogs.