The Rambutan is the fruit of a medium-sized tropical tree of the same name from the family Sapindaceae. It is native to Indonesia and Southeast Asia, although its precise natural distribution is unknown. It is closely related to several other edible tropical fruits including the Lychee, Longan, and Mamoncillo. It is believed to be native to the Malay Archipelago. The word Rambutan in Indonesian, Filipino and Malay actually means "hairy". This is due to the 'hair' that covers the fruit. In Panama, Costa Rica, and Nicaragua, it is known as mamón chino. There is a second species regularly for sale at Malay markets which is known as "wild" rambutan. It is a little smaller than the usual red variety and is colored yellow.
The rambutan tree is an evergreen tree. It grows to a height of 10-20 m. The leaves are alternate, 10-30 cm long, pinnate, with 3-11 leaflets, each leaflet 5-15 cm wide and 3-10 cm broad, with an entire margin. The flowers are small, 2.5-5 mm, and borne in erect terminal panicles 15-30 cm wide.
Rambutan trees are either male (producing only staminate flowers and, hence, produce no fruit), female (producing flowers that are only functionally female), or hermaphroditic (producing flowers that are female with a small percentage of male flowers).
The fruit is a round to oval drupe 3-6 cm (rarely to 8 cm) tall and 3-4 cm broad, borne in a loose pendant cluster of 10-20 together. The leathery skin is reddish (rarely orange or yellow), and covered with fleshy pliable spines, hence the name rambutan, derived from the Malay word rambut which means hairs. The fruit flesh is translucent, whitish or very pale pink, with a sweet, mildly acidic flavour. The single seed is glossy brown. It measures 2-3 cm with a white basal scar. The seed is soft and crunchy.
Rambutan is a popular tropical garden fruit tree. It is one of the best known fruits of southeast Asia and is also widely cultivated elsewhere in the tropics including Africa, Cambodia, the Caribbean islands, Central America, India, Indonesia, Malaysia, the Philippines, and Sri Lanka. The Thai province of Surat Thani is the biggest producer of rambutans. Rambutan production is increasing in Australia also. In 1997, it was one of the top three tropical fruits produced in Hawaii. It is also produced in Ecuador where it is known as "achotillo". In Sri Lanka it is mainly cultivated in small home gardens.