Category Archives: Trees

Killers and Healers – Oxymorons of Nature

You’ve heard of fire being a good servant and a bad master, there is the good side and bad side. This is the same with some plants. On one hand, they are poisonous, on the other hand, they heal. How does that work?
If you work in the medicine industry, you would be familiar with the famous quote from Paracelsus, the Swiss physician and alchemist : The dose makes the poison. For all these plants, it’s all about the amounts in the body. There is a therapeutic window where they cure, and above that, they became toxic.
Here are a few examples.

Snowdrops and daffodils

These popular flowers signify the arrival of spring. You’ve probably come across cut daffodil buds with long stems in the supermarket. They are usually at the entrance, by the cut flowers, and not far from the vegetable aisles. If bought and eaten by mistake, they will give you diarrhoea and vomiting.

Both plants contain a chemical called galantamine. Galantamine interferes with the nerve pathway responsible for muscle contraction. When a key enzyme is this pathway is blocked, it affects various muscle pathways, resulting in convulsions, vomiting and breathing difficulties.

It is this very feature that is exploited in chemical warfare like the organophosphate nerve agent poisoning in Salisbury. Both galantamine and those organophosphates compete for the same enzyme. The difference is that the former is temporary, whilst the latter binds to the enzyme permanently. Galantamine, by competing for the same enzyme, prevents organophosphates from taking out all that enzyme in the body.

Galantamine can also be used to treat Alzheimer’s disease. If you want more details @compoundchem gives very good explanation.

Yew Tree


Taxol (Paclitaxel) from the yew tree gained a lot of interest among organic chemists owing to its complicated structure. In the body, it blocks cell division. Today Taxol is a chemotherapy drug for several cancer types including breast and ovarian.

This is actually a poisonous plant. It was in the news recently for killing cattle in a field and even people. The poison remains even when the plant is destroyed. In humans, 50 needles of the yew tree will result in a fatal heart attack. The chemical causing this is not paclitaxel itself, but it is in the same family of molecules present in the tree. They affect the muscle contractions in the heart.


Foxgloves digitalis-354646_640

Like the yew tree, they contain a chemical that affect the muscle contractions in the heart. Ingestion of these compounds cause nausea, vomiting, diarrhoea and irregular heartbeat.

Its active molecule, digoxin, is used to manage heart conditions, such as irregular heartbeats and heart failure. Check out @compoundchem to read further on how it works.



Another poisonous plant is the infamous Belladonna, aka Deathly Nightshade. Contact or ingestion causes a range of symptoms ranging from dry mouth to hallucinations and death. This website gives a very description of its properties. Similar to galantamine, it works on the nervous system, on the smooth (involuntary) muscles. Literally translated, belladonna means beautiful lady. Ladies used to use this to dilate their pupils to look attractive. Today, this property is utilised, in the correct dose, in ophthalmology (atropine). Belladonna’s other chemical Scopolamine is used for motion sickness and nausea .

My middle-grade book, Secrets of the Great Fire Tree, describes the search of a cure for a disease from a little known tree. It is inspired by two tropical trees, the cannonball tree and the buah keluak tree. One is known for its healing properties, and the other, its poisonous fruit. Secrets of the Great Fire Tree is published by Aurelia Leo

Are there any poisonous plants or healing plants you know? Drop it in the comments below!

First published 1 May 2019. Updated 16 May 2020

Why Children Love these Tropical Trees

I am sure you have wrestled with the task of balancing screen time and physical activity. If you are a parent, you have an even more challenging mission to instil a positive lifestyle. Living in a Singapore, a metropolis with a tropical climate, it is all too easy to stay indoors in the cool air-conditioning. However if you need some persuasion to venture outside and get close to nature, let me tell you why local children love these four amazing tropical trees.

Red seeds of The Saga Tree

The saga tree sheds red seeds, hence its more common name the Red Bead Tree. Whilst some parts of the world, these red seeds turn them into jewelry, my association with these smooth seeds is a childhood game. This traditional game involved the skill of your little pinky; use it to flick one seed to the other without hitting or touching any other seeds in the cluster. The more seeds you have the longer the game. Like a game of marbles, each start with an agreed number of seeds and by the end of the game, some will have won more. Those who lose will go hunting for more red seeds. This tree is a favourite with children.

The trees reach up to 20m and opens in a rounded shape to provide a good amount of shade. As with all tropical trees, they have buttress roots to hold them firmly to the ground during thunderstorms. Notice in the photo how much canopy it offers. Although rain trees can grow up to 30m, in the third picture these saga trees stand taller than the majestic rain tree.

Its scientific name is adenanthera pavonina. These trees were taken at Alexandra Road, just next to Queensway Shopping Centre.

The Umbrella Tree, aka Rain Tree

You got a glimpse of the rain tree in the previous photo. It’s one of the hundreds you can see in Singapore, whether in residential areas or lining busy roads.

They can grow up to 30m in height and 20-30m in width. As mentioned before in my article about shades and Singapore, they open majestically like umbrellas and offer untold respite from the harsh sun in Singapore. If you venture outdoors in our hot and humid climate, they offer so much shade they are a great place to gather. You can organise picnics. The adults have a chat, and the children play chase. The younger rain trees are even short enough for some to climb.

The older the tree, the taller they get. These trees have to be cut back regularly; otherwise they can be uprooted in a heavy thunderstorm; falling on cars, blocking roads and hurting unwitting passers-by. Sadly, a couple of the taller trees were felled since I took the photo.

Cool Shades 4 Rain Tree enhanced C

Rain Tree by an overhead bride

Its scientific name is Samanea saman. These trees were taken at Tanglin Road, Bukit Timah Road and Marymount Road.

The Maze Tree aka Banyan Tree

If you do a search for amazing trees, you will get a long list of the most amazing, most wonderful trees, unique and spectacular trees in the world. All will show pictures of the beauty, height, age, shape, colour of the trees around the world. These are a gift from nature. Indeed they are all amazing trees. I cannot name the most amazing tree. But the banyan tree is one that amazes me. I call it the Maze Tree in my book, Secrets of the Great Fire Tree.

In the photo below, there are four banyan trees. From afar, they look like trees with thick trunks.

Why Children Love these Tropical Trees 9 C

As I described it in my book, vines drop from the branches and eventually form secondary trunks. As the tree grows older, more trunks are formed and a complex array form around the main trunk. Here are two pictures to compare side by side. Can you tell which is the younger tree?

Stand under one and you will be wowed by its size and beauty. It is every child’s dream to climb up a tree like this, with its many branches and matured aerial roots. You can let your imagination fly here: it could be a trap, a secret hideout, an ancient tree that speaks to you. Even young children will enjoy weaving in and out of the trunks.

The scientific name of the Banyan Tree is Ficus benghalensis. These trees were taken at Alexandra road, Kallang MRT station.

The Boat Tree aka African Tulip Tree

Why Children Love these Tropical Trees 16 CThis tree looks innocuous. It doesn’t have the grand canopy of the rain tree, neither does it have the trunks of the banyan tree. If you are taking a ride and you see the occasional scatter of red flowers amongst a wall of tropical trees, like the photo here, you’ve seen an African Tulip Tree.

Look at the two close-up photos. The brown finger-like moieties maturing on the tree win the hearts of children. When they are ready, they fall to the ground. If you wander under one of these on a dry day, you will find loads of them on the ground. They are shaped like a sampan, hence the nickname Boat Tree. If you remove the seeds within, and leave them to dry out, you have yourself a sampan.

Like pine cones, these fruits open up when dry and close when damp. See the photos below to follow the drying process. These ‘sampans’ have given little children untold pleasure at water play. In Singapore, after a heavy rainfall, the storm drains gush with rainwater. This is when older children conduct boat races and see whose boat survives the currents and travel down to the bottom.

In my previous article on Cannonball and Buah Keluak Trees, I described the source of inspiration for my book, Secrets of the Great Fire Tree. As you can see here, these are just four of the many amazing trees you see in Singapore. I would have loved to include all of them in my book. However, in the end only two made a humble appearance in the story. I have already mentioned the banyan tree as the Maze tree. If it were up to you, which of these trees would you use in the story?

This article was first published 15 Apr 2019. Updated 20 Nov 2019 for the official blog tour of Secrets of the Great Fire Tree, published by Aurelia Leo. I pledge to give 25% of the royalties from its sale to charity.


SotGFT Blog Tour all white 2 C

*I would like to thank Ria from Wildlife Singapore for her work and making her amazing photos available for free download.

*If you want to find out more about these trees, NParks is a good source of information.

A Sacred and Healing Tree


My book, Secrets of the Great Fire Tree, describes a tree central to the plot of the story. This tree does not exist. However the flowering position of the Cannonball tree is so unique it had to feature in my story. Its medicinal properties fitted the plot. I combined this with another fascinating tropical tree and created a hybrid. I used the Cannonball tree’s unusual trunk to create the appearance. My fictional tree is named the Great Fire Tree.

The Cannonball Tree is a tropical tree with anti-cancer, anti-bacterial and antifungal properties. A tall tree reaching to ~30m, the trunk bears its flowers. From afar, these delicate flowers give the impression someone has wrapped a voile round its trunk.

Close up, you can see clusters of yellow buds sticking out of the thick trunk near ground level. When in bloom, the petals are red. On this day of visit, the tree has just dropped its petals.

A few months later, the blooms were still not as prolific, but you can see a few more  blooms in this picture below. These fragrant flowers are used in perfume and cosmetics. In India the trees are planted near Hindu temples because the flowers look like the hood of the snake round Lord Shiva’s neck.

Notice the thin branches bearing the flowers. When the tree bears fruit, they dangle from these thin twigs off the trunk. From humble beginnings, the fruit grows to the size of a cannon. Hence its name. Below you can see the different maturing stages of the fruit. The mature fruits have hard shells, useful for making household items such as containers.

In my middle-grade book, I described the fruit dropping to the ground when ripe. On this day when I visited, I was lucky enough to find some on the ground. With the size that they are, they make quite a mess on the pedestrian walkway. If they should fall on the concrete pavement and not the grass verge, the shells crack open. They give out a pungent smell of stagnant rotting water. I had to hold my breath when I took these photos. Needless to say I did not hang around to take too many pictures.

While I love this tree for its unique flowering position, it is not the shadiest tree for a hot country like Singapore (see my previous blog on Rain Trees). It is a very tall tree, but all its leaves culminate at the top. Here are a couple of pictures to demonstrate how tall they are. You can also see how they form part of the backdrop of city living in Singapore, lining the edges of the roads to provide shade for pedestrians.

The scientific name of the Cannonball Tree is Couroupita guianensis. If you want more information of the tree, NParks is a great resource of tropical fauna. If you visit Singapore and want to see it in person, it can be found in the Singapore Botanic Gardens and Gardens-By-the-Bay. These trees were taken along Tanglin Road at the junction just before Tanglin Mall.

If you’ve enjoyed this post, then you might be interested in another two local trees also mentioned in my book. I’ve described them in a previous blog about tropical trees.

This article was first published 1 Apr 2019. Updated 2 Nov 2019 for the official blog tour of Secrets of the Great Fire Tree, published by Aurelia Leo.

SotGFT Blog Tour all white 2 C


Eating from the Dangerous Keluak Tree

I have written a few articles about tropical trees: Rain treeCannonball tree,  African Tulip tree, Saga tree and the Banyan tree. You will also know that I have written about the oxymorons of nature, about healing plants that also kill. On that note, let me introduce a poisonous tropical tree.

At the Singapore Botanic Gardens, a UNESCO World Heritage Centre, you will come across a warning sign under this innocuous-looking tree: The Dangerous Keluak.

The Buah Keluak Tree

The buah keluak tree, or the kepayang tree, is a tall tropical tree. Its scientific name is Pangium edule. Its fruit is the same size as the cannonball tree fruit, which are about the size of a galia melon. However, unlike the cannonball tree, the buah keluak tree’s fruit grows like most fruit, ie among the leaves. It has big leaves, heart-shaped and waxy. Its flowers are large and green. Like many tropical trees, it has buttress roots that spread far and wide.

Unlike the Rain tree, Banyan tree or Cannonball tree, this tree is not so distinctive in its appearance. The only buah keluak trees in Singapore are located in the Singapore Botanic Gardens. Here is another buah keluak tree; you can tell this one is younger that the one in the first picture.

Warning!TheDangerousKeluakTree 4 C

Even though it’s in the Botanic Gardens, most Singaporeans would not recognise this tree if they saw it again. However we will recognise the name. The buah keluak fruit is a local Peranakan dish, begging the question of how a poisonous tree produces a local delicacy? This brings to mind a BBC article I saw recently ‘How do people learn to cook a poisonous plant safely?’ When the South Americans were asked why they process cassava root in such an elaborate way, they reply ‘This is our culture.’

Warning!TheDangerousKeluakTree 5 C

This too is the same for the buah keluak. The tree is endogenous in Indonesia, a country famous for its beach holidays in Bali. Bali has been in the news recently due to the eruption of its volcano Mount Agung. Forming part of the Pacific Ring of Fire, Indonesia has hundreds of volcanoes. Living with active and extinct volcanoes are part of the Indonesians’ lives.   The volcanic soil and ashes play an important part in the treatment of the poisonous buah keluak fruit. When I visited, none of the trees had the fruit nor flowers, but in this information board, you can see what the actual fruit looks like. This is the same warning sign in the first picture, taken close-up.

Untreated, the nuts contain the deadly cyanide. With grooves on the outside, they are the size of a fist.

Warning!TheDangerousKeluakTree 6 C

To make the nuts edible, they have to be boiled and soaked overnight. The water is discarded and the boiling/soaking process repeated for five times.

Next the nuts are wrapped in banana leaves and buried in the Indonesian volcanic ashes for forty days. Although the nuts are treated already by the time they are imported to Singapore, I know some locals will repeat the boiling and soaking process again for a few more days, just to be on the safe side. They also scrub the shells in between the water change.

Peranakan Food

Buah keluak is a popular Peranakan dish. The nuts are hollow, but the inside of the hard shell is lined with a black paste. This colour is critical. Anything paler indicates incomplete treatment.

Before cooking, a small hole is made using the back of a heavy cleaver. They are simmered with spices.

Part of the fun of eating it is fishing out the paste from the shells, using chopsticks or miniscule spoons. Children like to stick their little fingers in instead. It sounds messy, but that is all part of the authentic experience. The paste has a distinctive musky flavour. Some recipes dilute the flavour with yellow bean paste. Many recipes use chicken or pork to accompany the dish. If you dine in a Peranakan restaurant, the dish can be served in two ways: with the nuts, or just the paste alone.

A tree’s poisonous fruit ends up on our plates as a delicacy. Its journey is so unusual that it inspired me to pen my middle-grade book, Secrets of the Great Fire Tree. Published by Aurelia Leo, the book is going on a Blog Tour 11-22 Nov 2019. This article is written as the launch to the countdown to the tour. Come along and join us!

SotGFT Blog Tour all white 2 C

Healing Lessons in London

I’ve come across physics the subject, and physician the healer, but the first time I encounter the word ‘physic’ was a couple of months ago when I visited a little treasure in London.


The Chelsea Physic Garden is located in Sloane Square. This place exists because of the generosity of Sir Hans Sloane, who made his fortune with chocolate milk. There was a little tribute to him in the garden.

This garden was built on an aspiration of achieving good health using plants. As you go around, you will find various sections you can relate to. I joined the free guided tour conducted by volunteers. They follow a general script to give you an overview of the place, which is useful for a plant pleb like me.

Garden of Edible Plants

This is a fascinating section. Amongst many things you can see here, our guide describe how tea physically came to UK, cultivation of black tomatoes and showed us the plants various alcohols came from.

Garden of Useful Plants

This included Technology, Perfumery, Hygiene and Cosmetics. Here are some pictures of the signs to give you a flavour of the place.

Medicines and Poisons

The word physic  is related to healing.  This was my whole reason for coming here. My guide had an interest in medicinal plants which was fortuitous as it meant that she touched on more of that as we went round.



She talked about the healing principles around the world, and highlighted some key healing plants. Periwinkle is pretty decorative plants common in Singapore, but I learnt its extract is used to treat diabetes in Jamaica. Even more interesting is that the extract contains two natural products I have heard of in my career as a medicinal chemist. Vinblastine and vincristine are used to treat leukemia. Up to that point I have never associated this plant to the research I once worked on.

In the same area of cancer, I know of Taxol from the yew tree because it gained a lot of interest among organic chemists owing to its complicated structure. But I have never seen the actual plant until now. Taxol is known for its healing properties for breast and ovarian cancer.


This is a poisonous plant. It was in the news recently for killing cattle in a field. But I quote Paracelsus, the Swiss physician and alchemist : The dose makes the poison. In fact, when you go round the medicinal section, you will see many such warning signs. What struck me on this visit was the common-sense faith in its visitors. The signs warn you about poisonous plants, and not to touch them. I have been to a different botanical garden where the section on poisonous plants was gated up, only available when there is a tour, which happened infrequently.


Another poisonous plant highlighted was the infamous Belladonna, aka Deathly Nightshade. Literally translated, bella donna means beautiful lady. Ladies used to use this to dilate their pupils to look attractive. Today, this property is utilised, in the correct dose, in ophthalmetry.


In the medicinal section, you can also gain the information without the guide. There are information stands for your perusal, which I did after the tour. I took my time to absorb the information available.


I’m not a gardening expert, but having grown up in a culture of mysterious concoctions of Chinese medicinal herbs and then worked as a medicinal chemist in rational drug design, I wanted to find a link to both worlds. The Chelsea Physic Garden fulfils this. This interest inspired my middle grade book, where my main character embarked on a journey to find a cure from a rare tree. Some of my characters used herbs to cure their ailments. Secrets of the Great Fire Tree will be published by Aurelia Leo on 28 May 2019. It is available for pre-order and requests for advanced reader copies can be made on Netgalley.

First published 1 Nov 2018. Updated 16 May 2019.

Shady parts of Singapore

In Singapore, a conscious effort is made to plant trees along pavements and footpaths. If you walked along a concrete path on a sunny day, you will experience shade, sun, shade sun, shade, sun. In this harsh, humid climate, you will certainly notice it when you have left the cool shade of one tree. The next tree offering shade might only be fifty paces away, but you only need a mere thirty seconds in the sun for the sweat to pour from your head.

Look at the picture below. You can see there is a lot of shade on this concrete path.

Cool Shades 1 Grasscutter in shaded pathway C

Shaded pedestrian concrete path

However, further ahead, there is a big gap of sunny path. This is because some trees offer more shade than others. Get to this section on any paths, and two things can happen:

(a) Heat-hating locals like me will cringe, moan “no shade”, pick up our walking speed to towards the nearest shade.

(b) Some of us will reach in our bags to for our umbrellas. Umbrellas sold in Singapore have special UV protection; they truly protect you from the heat of the sun. In the same picture on the left, you can just about see the pedestrian is holding up an umbrella to shade herself.

Here is a closer picture of a tree that barely offers any shade. It reaches up so high, almost in a vertical manner, and offers shade for about two strides only.

Cool Shades 3 Little shade tree C

In the picture below, see how the pedestrians consciously stand in the shade while waiting to cross the road?
Cool Shades 2 Raintree cropped concrete pathway 2015-03-28 10.18.06 C


This is a beautiful stretch lined with rain trees. I am always grateful when there are rain trees along my path. They open up like umbrellas. Sometime, their canopy open so much that they offer overlapping shade with the next tree.

Should you find yourself without an umbrella during a tropical rainfall, they will also offer you some respite from the deluge.

Because rain trees are my favourite trees, let me share a couple of more pictures of the tree close up. When you compare it against the buses, you can see how tall and majestic they are. As I said in my previous blog, this ancient tree is teaming with life. Look at the ferns that live on the tree. It’s like a gentle giant, cradling little children in its care. The scientific name of the Rain Tree is Samanea saman.


Much as I love these trees, I mentioned them only briefly in my middle grade book, Secrets of the Great Fire Tree, which will be published on 28 May 2019 by Aurelia Leo. It is available for pre-order and requests for advanced reader copies can be made on Netgalley.

Updated 9 May 2019. First published 15 May 2018


Do you know any great stories about trees?

Trees are not exactly something you’d expect to be the primary focal of a story, are they? They form the backdrop in woods and forests to hide and explore. But a story centred around a tree?

The first one I encountered was back when I was growing up in Singapore, in the days when it was still a developing country. Enid Blyton’s The Magic Faraway Tree. It’s got everything magical to whisk you away. It’s enormous, you can climb it and at the top you can get into magical lands of every kind. I could almost taste the toffee and fudge the children ate. At the end of the adventure, you whiz down the slippery slide to go back home. I could not get enough of the stories. Three books in the series was not enough.

A friend highly recommended Tolkien’s Lord of the Rings. Then the movies came out. Book or movie, they were long, arduous and mentally exhausting. But Treebeard in his Fangorn Forest kept me going. He was the light, in his anciently deliberate ways. Ultimately his anger was the turning point in the story when all seemed hopeless.

Both were written by English authors.

I later moved to England and got a glimpse of their world. In my twenty years living in England, I had grown used to deciduous trees, with their thin leaves that change to beautiful colours in the autumn. In time, they fall off and the bare trees become a common sight during the long winter months. Just look at the two pictures below, taken in a space of six weeks.

Then just when you’ve forgotten what it was like, the leaves come again in the Spring. By summer it was hard to imagine them being bare. The whole process repeats itself  in the autumn, reminding me how transient things are.

By the time Frances Hardinge’s (another British writer) The Lie Tree won the 2015 Costa Book of the Year, my fascination with trees was well established.

I returned to Singapore after living in UK for twenty years.

Even though I left UK in the summer, it struck me how, in Singapore, the place is teaming with life. Not because I was in a bustling city, but there is growth everywhere I look: the tall trees with buttress roots, the thick waxy leaves, the climbers that form green veils and the ferns that live on other trees.  Look at the thick waxy leaves in this picture below. The three men you see under the trees are grass-cutters, with petrol-operated machines. You find them dotted in places as you go about in Singapore. They keep the thick undergrowth and grass in check.

Here in Singapore, even the grass is thick. This is the type of grass commonly found in Singapore. They are about 0.5cm wide. The darker-leaf plant is a Mimosa plant. Its leaves close up when you touch it.


Mimosa plant growing among coarse grass

This long period of absence from Singapore meant I saw this tropical country with a new set of eyes. Instead of taking them for granted, I appreciated my surroundings for its uniqueness. They inspired the setting of my my middle grade fiction. It’s amazing what you can find when you look for something. Ever since I started writing Secrets of the Great Fire Tree, I found several books on trees.

If you know any great stories about trees, let me know in the comments below.

Secrets of the Great Fire Tree will be published by Aurelia Leo on 28 May 2019. It is available for pre-order and requests for advanced reader copies can be made on Netgalley.

Updated 8 May 2019. First published 1 May 2018.