The rambutan (pronounced /ræmˈbuːtən/; taxonomic name: Nephelium lappaceum) is a medium-sized tropical tree in the family Sapindaceae, and the fruit of this tree. It is native to Malaysia, Indonesia, The Philippines, Sri Lanka and elsewhere in 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, from where it spread westwards to Thailand, Burma, Sri Lanka and India; eastwards to Vietnam, the Philippines and Indonesia. The name rambutan is derived from the Malay word rambut, which literally means hairy caused by the ‘hair’ that covers this fruit, and is in general use in Malay and Filipino.
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 outer skin is peeled exposing the fleshy fruit inside which is then eaten. It is sweet, sour and slightly grape like and gummy to the taste. In Costa Rica, it is known as mamón chino due to the likeness of the edible part with Melicocca bijuga and its Asian origin.
It is an evergreen tree growing to a height of 12–20 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, apetalous, discoidal, 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, 2–3 cm, with a white basal scar. The seed is soft and crunchy. They are mildly poisonous when raw, but may be cooked and eaten.
It is a popular garden fruit tree and propagated commercially in small orchards. It is one of the best known fruits of Southeast Asia and is also widely cultivated elsewhere in the tropics including Africa, the Caribbean islands, Central America, India, Indonesia, the Philippines, and Sri Lanka. Thailand is the largest producer from Surat Thani Province Thailand. Rambutan production is increasing in Australia and, in 1997, was one of the top three tropical fruits produced in Hawaii. It is also produced in Ecuador where it is known as “achotillo.”
The fruit are usually sold fresh, used in making jams and jellies, or canned. Evergreen rambutan trees with their abundant coloured fruit make beautiful landscape specimens.
Rambutan found in markets that is harvested as picked from their stems (pictured right, individual fruits in a pile) , is commonly ridden with insects, prone to rot, and of relatively low viability per bunch sold, especially compared to other fruits.
The best quality rambutan is generally that which is harvested still attached to the branch (pictured above). It is less susceptible to rot, damage, and pests, and remains fresh for a much longer time than rambutan that has been picked from the branch.
Another indicator of quality is the ease of detachment of the flesh from the seed. An easily detachable flesh normally will have bits of the woody seed coating. Thus, it is a common Malay wisdom to not eat too much rambutan when one has a cough.