Litchi, longan and rambutan—fruits from a soapy family

litchis on Doi Ang Khang

A litchi orchard on Doi Ang Khang.


Penang, August 1, 1857. The members of two of the island’s Chinese secret societies, the Cantonese of the Ghee Hin Society and the Hokkiens of the Tua Peh Kong, detest each other. The Malays on Penang have their own bands, the Red Flag and the White Flag Societies, but the former are the associates of the Tua Peh Kong Chinese, whereas the latter are aligned with the Ghee Hins. The situation has become complex, and volatile. It’s the skin of a rambutan, one of South-East Asia’s most popular fruits, that ignites the explosion.

On that August day, in the middle of the rambutan season, a Chinese belonging to the Tua Peh Kong, for some reason or another, peeped into the home of a White Flag Malay. The latter was just peeling a rambutan so, affronted by this, he threw the skin of the fruit at the Peeping Tom in the street. The insulted Hokkien reacted angrily, and thus the Penang Riot began; eventually forces of 7,500 Red Flag-Toh Peh Kong men and 28,000 White Flag-Ghee Hin men were fighting each other with every conceivable weapon, from sticks and stones, to muskets and a cannon. After a battle of nine days hundreds of people were dead and a large section of Georgetown had been burnt to the ground.

Fortunately, no tensions of this kind exist in Chiang Mai nowadays, where during the rambutan season, from May until September, piles of succulent fruit are on display at all fresh markets and on many fruit stalls along the streets. The rambutan is the size of a golf ball and is adorned with many soft, curled spines. Its colour varies from pinkish orange with red spines to red with green spines. It may require some experience to peel the skin off to get at the translucent flesh. The latter is generally praised, and many consider the taste of the best varieties even superior to that of the related litchi and longan. The women running the fruit stalls build pyramids of their goods. The discarded peel is seen virtually everywhere.

Despite their ubiquity in this season, few rambutans are grown here in the north, as the tree prefers the humid climate of the south. Most are grown in Rayong and Chanthaburi provinces and down the peninsula south of the Khra Isthmus, where Nakhon Si Thammarat in particular is a well-known growing centre. The fruit is also widely grown in peninsular Malaysia — with the best being found in Penang — along with much of insular South-East Asia.

Its common name is of Malay origin, where it means ‘hairy thing’, while the scientific name is Nephelium lappaceum. In Thailand it is called ngo, a name that is also given to the frizzy haired Sakai ethnic minority living in the southern rainforest. The trees have a low trunk and are rather small, the foliage is dense and consists of globular ‘leaves’ (actually the leaflets of compound leaves). The bitter seeds contain a high amount of a fat that resembles cocoa butter, while the peel has been used for dying silk — but these usages are of minor importance compared to the flesh of the fruit.

rambutans and litchis

Left rambutans, right litchis.


Rambutans, longans and litchis all belong to the rather large tropical family Sapindaceae. Most species are trees, and many of them produce fruit with a high content of saponine, which gives them a very soapy taste and makes them non-edible. The name of this plant family is actually derived from this toxin, which, of course, is not present in the edible fruits.

While rambutans are imported from the humid equatorial belt, longans and litchis, which require a more temperate climate, are widely cultivated in northern Thailand. Much of the area has been converted into litchi and longan orchards, which are of great economic importance. A considerable part of the harvest is reserved for export to Singapore, Hongkong and elsewhere.


All three have rather similar types of fruit — one that usually does not open, so you have to do that by squeezing it — and, not surprisingly, they are considered as relatives within the same subfamily (Nephelieae) of the Sapindaceae.

The fruit of the litchi (Litchi sinensis), linchi in Thai, is similar in size to the rambutan’s, but its dry, red, leathery, and pimply skin is quite different. I find the sweet taste of its translucent, and succulent flesh superior to the rambutan’s and longan’s, but you may disagree.

Vendors of rambutans and litchis

Left: A vendor with ngop with a load of rambutans at the floating market of Damnoen Saduak. Right: Muslim street vendors in Chiang Mai with bunches of litchis for sale.



The rather small litchi trees are native to southern China. As the Chinese are particularly fond of this fruit, they tried to grow them wherever they settled in South-East Asia — often with limited success as they do not flourish in humid tropical areas. Of the three fruits, litchis are probably best known in the West. I recall from my youth that tinned ‘litchis in syrup’ used to be the dessert of choice in Chinese restaurants. Its canned juice is now popular in much of South-East Asia.

In Thailand, the fruit is mainly harvested from May to June, and Chiang Mai usually hosts a Litchi Fair during this period. Many litchi orchards are in the mountains and, in the season, you often see Hmongs driving their pick-ups loaded with the fruit down into town. When the season is coming to its end, the longan harvest is beginning — though actually, neither litchis nor longans are picked from the trees, but twigs containing a dozen or more fruit are broken off.


Longans (Dimocarpus longan) are economically even more important than the litchi. The fruit is smaller, and brownish, and also has a leathery skin, but this lacks the litchi’s pimples. The Thai call them lamyai, the Chinese name is ‘dragon’s eye’, while a closely related species is called mata kuching in Malay — which means ‘cat’s eye’. I think these names are allusions to the fruit with their skin peeled off, as then you can see the dark pit through the translucent flesh, making them look like eye-balls. Wild longans are fairly common in some of the north’s forests. According to the Field Guide to Forest Trees of Northern Thailand, their fruits are slightly smaller and more warty than the cultivated varieties, but equally delicious. However, until early in the twentieth century, local farmers grew longans with a rather large pit and relatively little flesh. Longan cultivation was not popular before princess Dara Rasmi (1893-1933), a favourite consort of King Chulalongkorn, introduced the now widely grown variety — which has become the symbol of Lamphun province, if not the whole Upper North.

longan orchards and details of fruits

Left: A longan orchard in Lamphun province. Centre: Poles propping up the branches. Right: Details of the ripening fruits.



Much of Lamphun province, including erstwhile rice paddies, have been converted into longan orchards. Many of the horizontally growing branches of the trees have to be supported by props to prevent them from breaking under their own weight. The annual harvest in the north varies greatly, but may exceed a hundred million kilogrammes, bringing a revenue of over a billion baht to the region. Lamphun province celebrates the longan harvest during an annual Lamyai Fair — usually in early August — which offers, besides masses of longans, parades with floats, a Miss Lamyai Contest, and drum-beating contests.

This fruit is believed to improve brain function, while a concoction of the dried fruits is traditionally used medicinally for various mental deficiencies such as amnesia and neurasthenia. Whatever the efficiency of this treatment, the fruits are, like litchis and rambutans, a rich source of vitamin C — up to twice the amount in oranges.

Dried longans — the dark brown pits removed and the flesh turned brown — are also used for making tea. Much of Northern Thailand’s longan harvest is dried and exported to China. In Chiang Saen, close to the Golden Triangle, you can see the Chinese freighters moored in the Mekong being loaded with thousands of boxes of them.

Interestingly, the longan’s (and litchi’s) dark brown pit is quite hard, and has  a smooth, shining surface, which remains free from the edible part, whereas rambutans develop a tissue (in the botanist’s terms a ‘sarcotesta’) that sticks to the seed. These anatomical details make eating litchis and longans much easier than eating rambutans. When eating the latter fresh, one may bite on the rather soft, almond-shaped pit which tastes very bitter. (Canneries have developed a punching-machine that removes the pit and leaves a square hole, which has inspired some gastronomic innovater to fill it with a tiny cube of pineapple.) What’s more, the rambutan’s peel can be pretty tough, so eating them, despite the fine taste, can be frustrating. This may explain why a rambutan skin, and not a banana peel, sparked off the historical riots in Penang.

One wild member of the soapy family of the rambutans may also be reduced to a glory of the past. Glenniea philippensis is a rather large tree producing very large fruits — the size of a small pomelo and weighing up to half a kilogramme. These large fruits taste delicious. However, the tree is extremely rare, and only a few specimens are still known to exist, one in Penang, one  in peninsular Malaysia, one in Sabah, and one in Luzon (Philippines). It is feared that this Giant Rambutan Tree will soon become extinct.

Text and images©Sjon Hauser