Sunday, June 21, 2009

10 Fruit Trees of Pulau Ubin 200609

Some RMBR volunteers met up on Saturday morning for an outing to Pulau Ubin cum durian feast. More about that in a later blog post! In this entry, ten fruit trees of Pulau Ubin which we saw will be featured. In horticultural usage, 'fruit tree' refers to a tree whose fruit is used for human consumption. So even though all flowering plants bear fruit, not all are called fruit trees. And 'trees' can be a misleading term...

The first fruit tree that we saw, which, at this time of year, is terribly hard to NOT notice was the Rambutan (Nephelium lappaceum). When I was a kid, I used to be unable to tell the difference between Lychee (Litchi chinensis), Longan (more than one species) and Rambutan. Well, there're all from the same family of Sapindaceae! Even now, I keep thinking that Lychee is Rambutan..and Longan is get the idea. Perhaps the following associations will help:

Rambutan - red and hairy (rambutan, derived from the Malay word rambut which means hairs)

- red and NOT hairy

Longan - brownish-yellow and NOT hairy

Rambutan trees grow in countries with tropical climates. They are evergreen ie. having leaves all year round. Some trees are dioecious while other are hermaphroditic.

The second fruit tree that we came across was that of the Custard Apple (Annona squamosa) (note: the common name refers to all three species in the genus Annona). This variety hails from the family Annonaceae which grows well in warm, humid climates. According to this website, "[t]here is a thick, cream-white layer of custardlike, somewhat granular, flesh beneath the skin surrounding the concolorous moderately juicy segments, in many of which there is a single, hard, dark-brown or black, glossy seed, oblong, smooth, less than 1/2 in (1.25 cm) long.". I remember eating a custard apple a very, very long time ago and thus cannot remember how it tastes like. Probably was not fond of it which explains why I've not eaten it ever since.

What's a durian feast without durians? In Pulau Ubin, a noticeable number of Durio zibethinus trees grow just along the main trail. When not fruiting, this tree, which hails from the family Malvaceae, can be distinguished by its leaves which have a bronze underside. There are 30 recognised Durio species but the one mentioned here is the variety which is available in international markets.

The durian has long been nicknamed 'the king of fruits'. The ripe fruit has a pungent, distinctive smell and comes in multiple segments. The seeds, found in shallow recesses in each segment, are covered in a soft and custard-like flesh, ranging from cream white to yellow and even red, depending on the species. Apart from the smell, the other distinctive feature is, of course, the husk, which is very prickly. Wallace, a famous naturalist, apparently said that for one to appreciate durian, he or she has to eat it three times. I used to love eating durians back when I was a kid but have since assiduously tried to avoid them (though what possessed me to eat some on Saturday is beyond me...).

Contrary to the title of this blog, the banana (Musa spp.) is not a tree but a herb - the world's largest herb, in fact. Basically, herbs are plants which have non-woody stems. The humble banana (family Musaceae) has its origins in Southeast Asia and over time, with the rapid spread of globalisation, it became well-known to the world. Musa comprises both dessert bananas (what we eat in Singapore) and plantains. The former is eaten raw while the latter has to be cooked or processed in other ways. Plantains have lower water content, making them drier and starchier than fruit bananas. They typically form a staple in the diets of people living in places such as Central America, the Caribbean and Peru.

The picture above shows the main stalks of banana plants which grow from rhizomes underground. In due time (if not already), the terminal inflorescence will grow out from the top of the stalk, and bear fruit. Each stalk produces one huge flower cluster and then dies. New stalks then grow from the rhizome. In summary, the growth of one main stalk is as follows:

Rhizome (produces more than one shoot but most are cut back in order to allow energy to be channelled to fruiting of the main stalk) -> new shoot (typically called a sucker) -> large leaves -> terminal inflorescence -> fruiting (bunch o' bananas) -> main stalk dies -> cycles repeats itself (main stalk forms from a new sucker of the same rhizome)

I was really confused about the whole process of propagation until I chanced upon these sites which can be accessed here and here (good diagram showing the parts of a banana plant). This other website details how the popularity of bananas spread and explains an interesting phenomenon - negative geotropism - which banana plants exhibit.

Hope you aren't suffering from banana overload (like I was). Here are a few more interesting things:

i. fibres are obtained from the stalks which can be made into material (for clothes) and other items such as bags. The pic on the right is a close-up shot of a bag made from banana fibres. It was given out by the Filippino restaurant, 7017 Flavours, on their anniversary. The staff there wear uniforms made from the fibre too.

ii. banana hearts (ie. male banana flowers) are used in dishes like rojak. They look like pink curlicues once cleaned off of gravy.

This pretty pink-streaked flower belongs to the Starfruit (Averrhoa carambola) (family Oxalidaceae).

Here, you can see the developing fruits which still have some way to go before ripening. The common name comes from the appearance of the cross-section of the fruit. It closely resembles a star, with both its (yellow) colour and shape.

Often eating with sour plum powder, the guava (Psidium spp.) (family Myrtaceae) is another fruit that is a favourite with locals. Apart from eating it fresh, guavas are also consumed in their preserved form. Personally, I prefer the preserved ones even though they remind me of curled-up pieces of dead skin (haha!).

When crushed, the leaves of this tree give off, what else, but a guava-ish smell.

I was surprised to see Cacao tree (Theobroma cacao) (family Malvaceae) growing in Pulau Ubin. Didn't think that they grow in this part of the world. Theobroma means 'food of the gods' in Greek, and indeed, processed cacao beans are what gives us cocoa from which the much prized chocolate is made. Each cacao pod contains 20 to 60 seeds (usually called beans). These contain a high percentage of cocoa butter, a fatty substance.

You'd think that with cocoa being so prized and all that everything about the plant must be grand. While flowers of many plants are pollinated by butterflies/moths or bees, cacao flowers are pollinated by...flies. Clearly, flies are not to be looked down upon.

While taking a break from writing this blog entry, I munched on some coconut candy - a sweet confection that is made from grated coconut. Coconut trees (Cocos nucifera) hail from the palm family of Arecaceae (Palmae is now considered taxonomically invalid), and are the only species in the said genus. Nearly everything about them is useful, from the nuts to the leaves.

Coconut palms are often seen growing by the coast for they are dispersed by water. The fruit itself has a hollow cavity that is filled with a liquid commonly called coconut water. The air-filled space allows the fruit to float on the surface of water.

I can't help but think of the Coconut Crabs (Birgus latro) upon the mention of Coconut Palms. These crabs have been observed to crack open coconuts whether by using their chelipeds or climbing up a tree and subsequently dropping the fruit to crack it open. Read more about their behaviour here and here.

This plant here is not a tree, but a climbing vine. The luscious (probably unripe) fruit here is a passion fruit (Passiflora spp.). Not sure if this is the kind that is consumed though. When ripe, the fruit is harvested and the juice, along with the pulp-covered seeds, are used in a variety of ways. In Singapore, it is not uncommon to find bubble tea that is passion fruit-flavoured.

Being a climbing vine, the plant has tendrils which it twines around a support structure. When mature, the evergreen leaves are deeply 3-lobed and finely toothed.

I 'expired' rather quickly that day and left out two other fruits which LK pointed out, namely, the Jackfruit and Nutmeg. After rooting around, I realised that I did have the resources to finish this entry (with a number 11 even), after all :D

Here we go...

Another fruit with a pungent smell is the Jackfruit (Artocarpus heterophyllus). It is the largest tree borne fruit in the world. The leaves are oblong, oval, or elliptic in form, 4 to 6 inches in length, leathery, glossy, and deep green in color. Juvenile leaves are lobed. This tree is commonly planted in and around housing estates. It is closely related to the Cempedak (Artocarpus champeden). Currently, I am not able to differentiate the two... Both hail from the family Moraceae.

Photo taken from

I'm not sure which species of nutmeg (family Myristicaceae) the ones found at Pulau Ubin belong to, but if I needed to hazard a guess, it would be Myristica fragrans, which is a commercially viable species.

The seeds are dispersed by big birds (which have bigger beaks and able to swallow larger fruits) like Imperial Pigeons and hornbills. For germination to occur, the seed has to swallowed and passed through the gut of the bird. Only then can the astringent mace (lace-like covering) around the seed be removed. With the dwindling numbers of big birds in Singapore, the nutmeg is suffering.

Nutmeg is used in cooking and baking as a flavouring. The powdered form available in supermarkets is obtained from grating the seeds. The mace is also used. Both impart a similar flavour.

Quite a few of the fruits featured are heaty, such as the Rambutan, Durian, Jackfruit and Cacao. Starfruit is cooling.

To recap, here is a list of the 10 fruits featured:

1. Rambutan (Nephelium lappaceum)
2. Custard Apple (Annona squamosa)
3. Durian (Durio zibethinus)
4. Banana (Musa spp.)
5. Starfruit (Averrhoa carambola)
6. Guava (Psidium spp.)
7. Cacao (Theobroma cacao)
8. Coconut (Cocos nucifera)
9. Passion Fruit (Passiflora spp.)
10. Jackfruit (Artocarpus heterophyllus)
(Additional) 11. Nutmeg (Myristica fragrans)


  1. Wow, we sure have delicious fruit trees on Ubin! Thanks for sharing this. I learnt a lot.

  2. since these are the kampung trees... use Malay name really helps to remember them correctly.
    Longan is mata kuching- which means cat's eye. Think of Cat's eye, think of longan (not the operculum, hee)

  3. Ria: Thanks! Bought rambutans from Pulau Ubin and they're really sweet :)

    Samson: Hahah ya that might help..thanks!

  4. Thanks for sharing... din know that there are so many fruits on the island.

  5. The correct name is Annona squamosa, not A. reticulata. Cheers, Joe Lai : )

  6. Justin: Thanks! I was surprised to find that there were so many fruits there too.

    Joseph: Thanks for pointing it out :)

  7. cacao and passionfruits sounds nice! i never knew that! thanks miss henrietta!

  8. ahzhong: uncle wang! haha..why the 'miss'! thanks for dropping by :)

  9. Thank you for sharing! I lived many years in Singapore and this brings back many fond fruit filled memories.
    I am hosting this month's tree blog carnival - the festival of the trees and this post fits perfectly with the theme of summer fruit bearing trees. Do swing by and take a look to see yourself featured!

  10. Arati: Hello! Thank you for visiting and featuring my blog! :) It's a pleasant surprise indeed. I may feature more greenery (fruit trees too) in the upcoming future!