Rambutan is a medium sized tree, 15-25m high, has a straight trunk up to 60 cm wide, and a dense, usually spreading crown.

The evergreen leaves are alternate, slightly leathery, yellowish-green to dark-green and somewhat dull on the upper surface.

The flowers are very small (0.5 cm wide). They are in long- stalked bunches near the twig ends amongst the leaves. There are many flowers to a panicle . There are no petals only 4-6 sepals , which are faintly woolly. Most, but not all, flowers open early in the day. Up to 100 flowers in each female panicle may be open each day during peak bloom. Initial fruit set may approach 25 percent but a high level of abortion contributes to a much lower level of production at harvest (1-3%).

The fruits hang in bunches often many to a bunch, on woody stalks on the outside of the tree. The fruit is about 5 cm in length and round to oval in shape with hairs or tubercles on its skin. Unripe fruits are green in colour and change to yellow or red when ripe. The skin is quite thin and pliable and is not attached to the flesh. The flesh is firm, white and translucent. It is sweet and juicy. Most rambutan trees propagated from seed are not true-to-type and usually sour. Male rambutan trees are also not uncommon. Selected clones produce thick, firm flesh which is sweet.

Rambutan is propagated by grafting, air- layering, and budding - the latter is most common as trees grown from seed often produce sour fruit. Budded trees may fruit after 2-3 years with optimum production occurring after 8-10 years. Trees grown from seed bear after 5-6 years. The fruit usually matures 15 to 18 weeks after flowering.

The most favourable climate for rambutan cultivation is within 12º of the Equator, at altitudes up to 600 to 700 m above sea level where the temperature range is 22-30º C and having well-distributed rainfall with 2,000 to 5,000 mm per annum.

Rambutan can be grown successfully in a wide range of soils but optimum growth and fruiting occurs on well-drained sandy loam or clay loam that is rich in organic matter. Rambutan grows well on hillsides with a moderate slope. The water table should be less than 3 meters from the surface. A pH range of 4.5 to 6.5 is considered appropriate for rambutan cultivation. At higher pH, iron and zinc deficiencies ( chlorosis , leaf yellowing) are common.

Irrigation is not widely used in most of the production areas since rainfall is adequate for the plant's needs. Irrigation is only necessary in areas where the rainfall is lower than optimum or where the rainfall pattern is uncertain.

The rambutan is native to Malaysia and commonly cultivated throughout the archipelago and southeast Asia. Many years ago, Arab traders introduced it into Zanzibar and Pemba. There are limited plantings in India, a few trees in Surinam , and in the coastal lowlands of Colombia, Ecuador, Honduras, Costa Rica, Trinidad and Cuba . Some fruits are being marketed in Costa Rica. The rambutan was taken to the Philippines from Indonesia in 1912.

It thrives in humid tropical lowlands (sea-level up to 600 m) within about 17° from the equator and an annual rainfall of over 2500 mm.

It thrives in humid tropical lowlands (sea-level up to 600 m) within about 17° from the equator and an annual rainfall of over 2500 mm.