Bugs Busters of Borneo

The nutrients-poor soil of the kerangas and peat swamp forest have driven many plants to supplement their autotrophic existence by other nutritional means. Borneo has an astonishing  variety of such plants - as I discovered during a day trip at a kerangas bordering a peat swamp forest .

Under the full glare of the sun and on persistantly wet sandy area, the sundew Drosera burmanii coexist with a population of bladderwoth Utricularia - which would almost be unnoticeable were it not for the yellow bloom.

 

The tentatcles of the Drosera burmanii are tactile and produce both a sweet fluid and a sticky glue - these attracts insects from which they then surround and entrap. The speed of movement of the tentalces in this species is one of the fastest in the genus - closing in on the prey between 5-10 seconds.  

The dimunitive nature of these plants mean that they easily be outcompete by larger, faster growing plants in richer soils so they are restricted in bright, acidic and nutrient-poor area 

The pitcher plant genus Nepenthes has the most diversity in Borneo and Philippines. Unlike the previous species, Nepenthes do not have movable parts to ensnare their prey. One of the largest lowland species Nepenthes rafflesiana shown below- demonstrate its usual modus operandi - trapping, drowning and assimilating invertebrates in its large pitchers. Note the large lid sheltering the pitcher in this photo - it serves to prevent dilution of the digestive enzymes from rain water. 

This species was actually first discovered in Singapore by Dr William Jack in 1819. 

 

Nepenthes ampullaria, on the other hand, has a tiny lid, which flips away from from the pitcher opening. This species does not catch much insects - instead it relies on leaf debris and other organic waste dropping into the pitchers and so it clearly wants the lid out of the way. Its pitchers also do not have slippery inner wall and very little nectar gland which produce insect attractants....

....the plant branches repeatedly to form a network of pitchers on the floor. This maximise the capture rate of any fallen organic matter.

The red-pitcher form is very attractive and has great horticulture value. It seems to be restricted to Borneo

The red speckled form is common throughout its range.

The Borneo endemic Nepenthes bicalcarata has a pair of downward facing fangs growing from the  the pitcher peristome.  The function of this is still a matter of debate. Although it feeds on the carpenter ants that nests in its tendrils, it also benefits from a symbiotic way since the ants are shown to provide housekeeping service by removing excess undigested organic material, thereby preventing bacterial / fungal proliferation and early demise of the pitchers.

The pitchers are medium size and the red variety is quite horticultural.

While most Nepenthes are indiscriminate when it comes to food, Nepenthes albomarginata is rather picky - specialising in trapping termites. This species has a ring of pale hairy cells around the rim of the pitchers which somehow termites cannot resist feeding. The inevitable eventually happens and the pitcher will soon be filled with termites after sacrificing some strands of hairs.

There are 2 forms - the lowland green form .....

and the attractive dark form from higher elevation.

Nepenthes mirabilis is one of the most widely distributed species and the normal form has rather unremarkable attributes although the variety echinostoma, which I could not find, has surreal and weird peristome. In my previous post I had found pitchers filled with ants.

The pictures below look very much like the lower pitchers of N. rafflesiana but I think it is the hybrid with N. ampullaria known as Nepenthes  xhookeriana

This is another hybrid, I believe Nepenthes rafflesiana x mirabilis and it appears that one of the parent is very red. Natural hybrid is very common amongst Nepenthes particularly in high diversity area like Borneo where the different species co-exist in the same area.

Myrmecodia tuberosa

Out of the 600 genera from the Coffee family (Rubiaceae), there are more than 20 that are known to be Myrmecophytic - which means living in close association with ants. Typically the ants provide nutrients and protection in exchange for the abode. Some of the tuberous epiphytic myrmecophytes, pictured above from Huxley and Jebb's paper, are actually rather interesting horticutural subjects eg Anthorrhiza, Hydnophytum, Myrmecodia, Myrmephytum and Squamellaria. Other genera are less well known, like Myrmeconauclea, Nauclea and Milletia which are large shrubs, trees or vines.

Myrmecodia tuberosa is widely distributed throughout SE Asia and N. Australia. Unlike its close relative Hydnophytum, it is armed with spines which concentrate at its caudex. However, its most effective mode of protection is its tenant - the ants. Mind you these are certainly not the docile critters we are familiar with - they earn their keep ! It has been reported by Maschwitz et al that ants from genus Cladomyrma would linger more than an hour on the body of an unfortunate botanist to inflict painful bites that resulted in red itchy dots for days. Its means of protection is so effective that the even pollinators are deterred - its small tubular white flowers being self pollinating. The berries may be dispersed by the ants themselves but their bright orange colour also attract birds like flower peckers which can take them in mid flight.

Throughout its range, both Myrmecodia tuberosa and Hydnophytum formicarum are consumed by local communities for medical purposes. The water boiled with the whole plant is taken as tonic for liver, heart, digestive system as well as wide range of ailments like cancer, hepatitis and rheumatism. A person I acquainted with once visited New Guinea and brought back a few of these wondrous plants which I had no doubt to be a more exotic species. When I requested to purchase one from him, he was unyielding, claiming that it was needed to treat some undisclosed ailments.

I do not encounter this plant frequently in Peninsula Malaysia but in Sarawak, in the mangroves of Bako, kerangas of various regions and even trees beside a small stream, they occur in very large but concentrated numbers, usually with other ant-loving epiphytes.

A closer look at the entrances to ant chambers within the caudex. This particular form does not have the leaf shield called clypeoli.

Growing with a Pachycentria constricta, another myrmecophyte from Melastoma family, on the same branch.

Hanging over a small brown stream at a depleting forest.


This plant is best grown from seeds as transplanted adults plucked from the trees tend to fare poorly. It should be grown like a succulent and as you can see from the habitat photos, they do grow under the full scorching sun although partial shade would be better for smaller specimens. I found that they tended to succumb to rot more easily than Hydnophytum formicarum. A regular feeding of foliar fertiliser will ensure rapid progress and fruit formation.

Ref:

Huxley, C.R. & M.H.P. Jebb. 1991a. Blumea 36: 1- 20.

U. Maschwitz et al Malayan Nature Journal 1989 43: 106-115

A.F.S.L. Lok et al, Nature In Singapore 2009 2: 231–236

Raffles Hotel for Formicids

When modern Singapore's founding father Stamford Raffles returned to this tiny island in 1822, he found himself in a rough patch with William Farquhar, the deputy he empowered to govern this island before he sailed to Bencoolen to further his ambitions. Farquhar's apparent laissez faire style of governance was just not of his liking, although the local businesses were having a roaring good time, not just in mainstream commerce, mind you, but also in gambling, opium trade, slavery and other unmentionables that were part and parcel of the roaring good time.

Raffles would have none of it, and promptly outlawed all of these.... his strict moralistic upbringing clashing heads on with the old man and his pro-business ideas....

In between the reeling and dealing, Raffles took to exploring the woods with his botanist friend, Nathaniel Wallich, an activity he was known to enjoy very much. During one of their excursions in Singapore's wilds, they found this strange ant-harbouring Dischidia vine.
Each vine was observed to bear two types of leaf, one that looks like small flat tortoise shell hollowed out on the inside and the other that looks kind of like pitchers of Nepenthes with a very small opening. For wandering ants seeking a roof over their heads, these leaves would draw them like a pundit to a soapbox, a gambler to a casino or any man left standing, after the Decepticons' onslaught, to Megan Fox....

....in gratitude, the tenants would crap and leave whatever bodily leftovers inside the leaf, providing the malnourished vine a source of recycled energy. At times, the ants may even be called up to defend their abode from parasites or hungry herbivores...or curious botanists !
The ants' leftovers are much appreciated, as this cross section of one of the hollow leaves show. Roots extend hungrily deep into the ant nest to suck up whatever is available.

Many Dischidia species have modified leaves serving as ant hotels; this species, however, is the largest one. In 1831, Wallich described this plant in his book Plantae Asiatic Rariores and proceeded to name this plant Dischidia rafflesiana, in memory of his good friend who, by then, had passed. However, it was later found to be synonymous with a plant named Collyris major, described some twenty years earlier, so after a taxonomic revision and applying the strict nomenclature rule, this plant should now be correctly called Dischidia major.

The name had changed, but the plant's the same. The ants don't care a hoot. Even Sir Stamford, I suspect, might not be stirred - after all he already had the largest flower in the world named after him.

But I'd bet he would be reeling if he knew that this island nation he had founded just gave out its first gambling license to a casino, almost two hundred years after he out-lawed it.

Cauldrons of mass destruction

It was a seemingly normal warm cloudy evening.

I was travelling along a little-travelled bitumen path at a little-known corner of Borneo when I caught sight of these curious little pitchers dangling from a vertical slope rising from both sides of our path.
Elegant in pastel hues and seemingly harmless....yet there was something unholy about them....

Curiosity got the better of me as I lifted one of the pitchers and peered into its murky crevice.....

.... what I saw was a massacre of the highest order, a genocide so foul it would stink the Seventh Heaven. Bodies were everywhere, some still intact, others had been disfigured to such extend that rendered identification impossible.

With a heavy heart and heavier footsteps, I made my way gingerly back to the town.

Fortunately there was curry chicken for dinner, which was truly therapeutic for a bitter soul ....

Nepenthes mirabilis, a widespread and very variable plant in SE Asia. This is the common form which is found from S. China down south all the way to Borneo and spreading as far east as New Guinea. While the major diet of Nepenthes albomarginata is termites and that of ampullaria is leaf-litter and droppings, this species is particularly adapted for trapping many types of live insects, using the pinkish pitchers and extrafloral nectaries concentrating on the lids and mouths as bait. The lids and rims of the pitchers are both treacherously slippery so any critters landing there will ski briefly to the well of death, where the marinating fluid, which can have a pH as low as 2 if its freshly secreted, will send them to their afterlife.

Just as a guide, I found that commercial undiluted white vinegar typically has a pH of 2.4 - you can always check out its effect on an ant if you are morbidly curious....

Porcelain....Hoya coronaria

Along a coastal road in Northern Johore, we found flowering vines of Hoya coronaria curling about some coastal vegetation. The hairy stem and leaves are coarse to touch and the vine itself is quite thick, about 1.5cm in diameter.

While the plastic-like flowers are attractive, this vine needs plenty of space and blooms infrequently. This, unfortunately, is generally true of species in the Eriostemma Section from which this plant belongs. To induce bloom, place it in full sun ; some people also suggested putting lime in the medium or subject it to water stress.

Variations of Nepenthes albomarginata

Usually considered an intermediate-growing species (ie needs cool growing condition), we were surprised to find this pitcher plant growing on white sand under the shade of shrubs in extremely hot lowland kerangas forest in Sarawak. The more common form in cultivation comes from highlands, a famous one being the Cameron Highland form from Peninsula Malaysia. This is rather unfortunately, of the plain green form.

A much more beautiful variety, supposedly found only in Gunung Mulu, is dark purple or black. I saw this on sale in a Singapore nursery just a few days ago, but the price was rather cut-throat.
Whatever the forms, this distinctive species has a pale ring around its lid made up of white fine hairs. It uses this to attract its prey - termites. The critters would chew on the hair and some would inevitably drop into the slippery death trap.
Shooting the smokey pitchers against a grey concrete background create a moody monotone effect with just a tinge of green colour showing. Without spending a cent, I had acquired 30 or so images to look at whenever I please and was contented to put the plant back on its rack.

Prudence in the age of recession.