The Rambutan (Nephelium lappaceum) is a medium-sized tropical tree in the family Sapindaceae, native to southeast Asia, and the fruit of this tree. It is believed to be native to the Malay Archipelago although its precise natural distribution is unknown. It is closely related to several other edible tropical fruits including the Lychee, Longan and Mamoncillo. In Costa Rica and Nicaragua, it is known as mamón chino. In Guatemala it is known as Rambutan.
The rambutan is a fruit considered exotic to people outside of its native range. To people of Malaysia, Thailand, the Phillippines, Vietnam, Borneo, and other countries of this region, the rambutan is a relatively common fruit the same way an apple is common to many people in cooler climates.
The fruit is a round to oval drupe 3-6 cm (rarely to 8 cm) long 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 Malayan 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, 2-3 cm long, with a white basal scar; it is poisonous and should not be eaten with the fruit flesh.
Rambutan roots, bark, and leaves have various uses in medicine and in the production of dyes.