Azadirachta indica, commonly known as neem, nimtree or Indian lilac, is a tree in the mahogany family Meliaceae. It is one of two species in the genus Azadirachta.A. indica is a medium to large, deep-rooted, evergreen tree, to 15(30) m tall, with a round, large crown to 10(20) m in diameter; branches spreading; bole branchless for up to 7.5 m, up to 90 cm in diameter, sometimes fluted at base; bark moderately thick, with small, scattered tubercles, deeply fissured and flaking in old trees, dark grey outside and reddish inside, with colourless, sticky foetid sap. Leaves alternate, crowded near the end of branches, simply pinnate, 20- 40 cm long, light green, with 2 pairs of glands at the base, otherwise glabrous; petiole 2-7 cm long, subglabrous; rachis channeled above; leaflets 8-19, very short petioluled, alternate proximally and more or less opposite distally, ovate to lanceolate, sometimes falcate (2) 3.5-10 × 1.2-4 cm, glossy, serrate; apex acuminate; base unequal. Inflorescence an axillary, many-flowered thyrsus, up to 30 cm long; bracts minute and caducous; flowers bisexual or male on same tree, actinomorphic, small, pentamerous, white or pale yellow, slightly sweet scented; calyx lobes imbricate, broadly ovate and thin, puberulous inside; petals free, imbricate, spathulate, spreading, ciliolate inside. Fruit 1 (or 2)-seeded drupe, ellipsoidal, 1-2 cm long, greenish, greenish-yellow to yellow or purple when ripe; exocarp thin, mesocarp pulpy, endocarp cartilaginous; seed ovoid or spherical; apex pointed; testa thin, composed of a shell and a kernel (sometimes 2 or 3 kernels), each about half of the seed’s weight (Orwa et al., 2009).
Neem Tree's facts
Azadirachta indica is a fast-growing tree that can reach a height of 15-20 m, though it occasionally reaches 35-40 m.
Very young leaves are reddish to purplish in colour. The shape of mature leaflets is more or less asymmetric and their margins are toothed (dentate).
The white and fragrant flowers arise from the junction of the stem and petiole (are arranged axillary), normally in more-or-less drooping flower clusters (panicles) which are up to 25 cm long. These branching inflorescences, bear from 150 to 250 flowers. An individual flower is 5-6 mm long and 8-11 mm wide.
Neem Tree's Behavior & 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 400–1,200 millimetres (16–47 in). It can grow in regions with an annual rainfall below 400 mm, but in such cases it depends largely on ground water levels. Neem 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 21–32 °C (70–90 °F). It can tolerate high to very high temperatures and does not tolerate temperature below 4 °C (39 °F). Neem is one of a very few shade-giving trees that thrive in drought-prone areas e.g. 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.
Neem Tree's Feeding
It is an autotrophic organism.
Neem Tree's Reproduction
Azadirachta indica reproduces mainly from seeds which are dispersed by birds and bats that eat its fruit. Its seedlings can germinate and grow in dense shade. This species has been widely distributed as a very beneficial tree to many drier parts of the world and is still being spread and planted - even in places where it has become invasive.
Neem Tree's Conservation
It is abundant.
Neem Tree's Relationship with Humans
It is a Source of medicine/pharmaceutical Traditional.
Neem Tree habitat
Azadirachta indica is a small to large tree species, varying from 12–24 m in height (Koul et al. 1989). It grows in arid regions often in dry open bush (FAO 2017) or in deciduous thorn forest (CABI 2015). The species has deep tap roots so is able to survive in drought conditions and in sandy, leached soils (Koul et al. 1989). It cannot tolerate water logging. This traits enable the species to move onto degraded land and hence they can play an important role in maintain soil layers and moisture in dry zones (CABI 2015). The species is fast growing and begin reproducing at five years, however, best fruit production occurs after 10 years of growth (Koul et al. 1989). The species flowers at different times of the year depending on the locality of the individual but fruiting follows the rainy season (CABI 2015). Seed is dispersed by gravity and seeds do not exhibit dormancy (Koul et al. 1989). The species can also reproduce vegetatively though suckers (CABI 2015).
Neem Tree threats
Azadirachta indica has few serious pests, but several scale insects have been reported to infest it. For example, Aonidiella orientalis (feeding on sap of young branches and young stems), which is the most vigorous pest. It is also affected by Pulvinaria maxima and Helopeltis antonii which both feed on the sap. In India, a shoot borer damages the plant. Rats and porcupines attack and occasionally kill A. indica seedlings and trees by gnawing the bark around the base. Mistletoes that affect A. indica are Dendrophtoe falcata and Tapinanthus spp. In India and elsewhere, Psuedocercospora subsesessilis is the most common fungus attacking the leaves, causing the shothole effect. In India, the bacterium Pseudomonas azadirachtae may damage leaves (Orwa et al. 2009).
This pests and diseases are not considered major threats to the global A. indica population.