Mangrove Lime (Merope angulata) at Mandai Mangrove

I have been really busy for the past few weeks, and thus was really glad to have a break to explore Mandai Mangrove today with LK and MC.

And the biggest surprise of this trip must be this!


We were exploring around when I saw this bush which looked somewhat familiar...


I decided to take a closer look. And yes indeed, it's what I thought it was - a Mangrove Lime (Merope angulata)! Although it was stated in the "Guide to Mangroves of Singapore" that it can be found here, I did not really expect to see one so easily. In fact, my main objective here was to search for the Kacang Kacang (Aegiceras corniculatum), which I had a photo of the fruits at Ubin previously, but before I managed to get some shots of the flowers, the tree was bulldozed...

Anyway, (Merope angulata) is a rather rare mangrove associate in Singapore, and even many of my friends have not seen it before! Can't remember where I last saw it though... could be Sungei Buloh or Kranji...


According to "Mangrove Guidebook for Southeast Asia", Merope angulata (from the lime family Rutaceae) is a broadly-branching, shrubby, occasionally scrambling, low tree, up to 3 m tall. It has (often paired) woody spines located in the axils and the alternate, thickly leathery, aromatic leaves have transparent dots.

The leaves are covered with minute glands (visible as translucent dots when held to the light) and have a resinous, lime-like odour if bruised. The flowers are white and bisexual, while the ripe fruits are yellow, and are oblong or ovoid triangular in shape with 3 flattened sides so that the fruit is triangular in cross-section. Within the fruit are 3 chambers which each contain 1 large, long, flattened seed.

This plant is used to treat abdominal complaints and assist womb contraction after childbirth.


According to my mum, there were a few of these shrubs at my grandma's old house at Punggol last time. (No wonder I always find it to be rather familiar. Those good old days...) My mum used to pluck the fruits to eat, though they are rather sour. Sometimes, they also dried the fruits, and chewed them.

As we went on exploring, we found 2 other trees! Unfortunately, we did not really get to further explore much as the sky was turning really dark, and we had to leave, even before finding the Kacang Kacang that I had wanted to find...

But within the short time that we had, we still managed to see a few interesting things along the way...


We also found a young Ipil (Intsia bijuga). According to "Mangrove Guidebook for Southeast Asia", this deciduous tree can grow up to 40m tall! This tree has very hard and good quality timber that is very durable, resistant to insects and weather. It is often used for building houses (especially house posts) and bridges. Very durable, resistant to insects and weather. The bark and leaves are used as medicine to treat diarrhoea. The seeds are fried, soaked for 3-4 days, then boiled and eaten.


Here's a look at the mangrove habitat at Mandai.


We also found a huge patch of Beccari's seagrass (Halophila beccarii). This seagrass is said to be rather rare, though sometimes I do wonder if the researchers have been looking at the wrong type of habitats. It can be found in several mangroves in Singapore, and I will assume they can probably be found in many of the mangroves in the region. But of course, I am no expert so I could be wrong...


We came across this blooming Caesalpinia crista. The seeds are supposedly used as marbles by children, and are also used to treat malaria and parasitic worms. The leaves are used to treat Hepatitis A.


There were patches of Sea Holly. This is Acanthus ilicifolius with the pretty purple flowers.


It appeared that some students were doing some research project here, and we saw several flowers of the Tumu Merah (Bruguiera gymnorhiza) being tagged.


We found a lot of Face-banded Crabs. The above is probably a Perisesarma eumolpe.


This one has a yellow face, so I am not really sure what species it is.


There were lots of Orange Signaller Crabs (Metaplax elegans) too, but they were really hard to take photos as they were really shy... The male crabs wave their orange claws to attract females, and hence the common name.


Like other mangrove areas, there were lots of clams here too. The above is probably a Lokan (Geloina sp.). They were collected in the region for food.


We also saw this little Mangrove Horseshoe Crab (Carcinoscorpius rotundicauda). The roe of the females are said to be very toxic, and can be lethal when consumed.


On the way out, we saw this pretty Oriental Whip Snake (Ahaetulla prasina). Learned from MC that to tell it apart from the Big Eye Green Whip Snake (Ahaetulla mycterizans), just look out for the yellow line running by the sides of its belly.


And then came a train, and the rumbling probably disturbed the snake so much that it moved further up the tree until we lost sight of it...

It was certainly a good trip, even though we had rather little time here due to the weather. It started raining when we were washing up. I would certainly want to visit this mangrove again. Hopefully to find the Kacang Kacang, and also, to get some photos of the ripe Mangrove Lime fruits.