This useful tropical tree is Neem, Azadirachta indica. It belongs to the mahogany family, Meliaceae, along with true mahoganies and Cigar Box Cedar. It is native to the Indian subcontinent and nearby parts of southern Asia but has been planted widely across the tropics, including the Caribbean.

Neem usually grows as a medium to large evergreen tree with a straight trunk, spreading branches and a broad, rounded crown. In a severe dry season, it may shed some of its leaves, but it often remains green when many surrounding trees have become bare.

The leaves are compound, with several narrow, pointed leaflets arranged along a central stalk. The edges of the leaflets are sharply toothed, giving the foliage a slightly jagged appearance.

Fresh leaves are often light green and become darker as they mature. If crushed, they release a strong, bitter scent.

The flowers are small, white and fragrant. They appear in loose, branching clusters among the leaves. Although each flower is modest, a flowering tree may produce thousands of them, attracting bees and other pollinating insects.

After flowering, Neem produces smooth, oval fruits. These begin green and become yellow or yellow-green as they ripen. Each fruit contains a hard seed surrounded by a thin layer of pulp.

The seeds are especially important because they contain oil and several biologically active compounds. Neem oil is used in soaps, cosmetics and horticultural products. One of its best-known compounds, azadirachtin, can interfere with the feeding, growth and reproduction of certain insect pests.

Neem-based products are often described as natural pesticides, but “natural” does not mean harmless. Concentrated preparations must still be used carefully because they can affect beneficial insects and may be unsafe if swallowed or applied incorrectly.

Almost every part of the tree has a history of traditional use. Leaves, bark, twigs, seeds and oil have been used in medicines, personal-care products, animal treatments and household preparations. Kew records medicinal, environmental, social, food, fuel and poisonous uses for the species. These traditional uses should not be taken as a recommendation for self-treatment.

In parts of South Asia, small Neem twigs have traditionally been chewed and used to clean the teeth. The tree is also planted for shade, fuelwood, wind protection and the rehabilitation of dry or degraded land.

Neem tolerates heat, drought and relatively poor soil once established. Its resilience has made it valuable in dry tropical landscapes, although its ability to seed freely can also allow it to spread beyond cultivation in some regions.

This is therefore a tree with two very different qualities: it is an attractive shade tree with fragrant white flowers, but it is also a source of powerful bitter chemicals that discourage many insects and grazing animals.

When presenting Neem to a group, the best features to point out are the sharply toothed leaflets, the clusters of tiny white flowers and the yellow olive-like fruits. Together, they identify one of the world’s most widely used tropical trees.