Wednesday, April 1, 2020

What Social Distancing .... ?

Caterpillars of Painted Jezebels sharing the leaf of parasitic mistletoe Dendrophthoe sp. Ths host tree (Wrightia religiosia) is completely untouched.

Friday, March 27, 2020


What the fig is that ??? 

Its a geocarpic fig actually, meaning that the figs are actually produced at ground level to benefit animal dispersal.  This particular species is Ficus uncinata which we found in central Kalimantan lowland forest close to a stream.

Figs emerge from  long hairy stolons that dangle down a branch and slide below the leaf litter. The seed dispersers are pigs, deers and mouse deers, which are not deers actually but more related to pigs. The spiky hooks on the pericarp is decorative but their real  purpose is to discourage ingestion by ground birds like pheasants and jungle fowl which have powerful gizzard that destroy the seeds


* cartoon from D. Eisikowitch and M. Ghara Acta horticulturae October 2017

 Now abit of biology.

Figs may be monoecious (where male and female flowers appear inside the same fig) or dioecious, where  different trees bear either all-male or all-female figs.  Ficus uncinata belongs to the latter category, which can be represented by either c (male) or d (female) figs. As you can see from the cartoon, the male fig actually contains many female short styled flowers, which are sacrificial in function and will not develop  seeds (as opposed to only long style ones in the female fig). The female pollinator, which is a species specific pollinator wasp, enter from a pore called ostiole and attempt to insert its long ovipositer via the style into the ovary to release the eggs but only succeed to do so in the short-style flowers in male fig,  the style in the female figs being too long for the ovipositer to reach the ovary. The eggs hatch in the male fig and induced gall formation which nourish the larvae - while the female figs, once pollinated, develop seeds and not galls. Hence, the fig offered its short styled female flowers as food for the wasp in exchanged for the long style flowers to be pollinated .... both the fig and wasp goes home happy.

This particular tree is a male as evidenced by the long stamens (white strands at top left) and the galls inside. 

Against the trend in the competitive, selfish natural world, the fig and the pollinator wasp work in such perfect mutualism  that it seems inevitable that there has to be a hacker, a lock picking free loader to spoil the fun. This comes in the form of a parasitic wasp, which the way, is really cool....
 .... this is another type of fig which we saw in Indochina. Can you see the tiny parasitic wasp at the top left fig ?

This wasp does not pollinate the fig - in fact it preys on the larvae of the pollinator wasp resulting in lower seed yield. Here you can see it inserting its skinny ovipositor through the pericarp

If you try pushing a strand of hair through the unripe fig, you will find that it will be an exercise in futility. However, this ovipositor is no ordinary strand of hair - its a material scientist's dream - not only does it has chemical and mechanical sensors, its ultra sharp tip is reinforced with zinc and throughout its length tiny pits are strategically located to allow it to bend rather then snap and break. This appendage allows this wasp to punch and feel its way into the area of the fig where the larvae of the pollinator wasp reside where it will deposit its eggs and gate crash the perfect party.

They are so cool that they can be forgiven for being the bad guys in this overall scheme of things ....

Friday, March 20, 2020

Hoya lacunosa

This is a form of Hoya lacunosa we found in S. Peninsula Malaysia. The small tapering leaves have prominent protruding venation. It is reminiscent of the purple flowered Dischidia hirsuta, just less hairy.

Its a neat little vine that has typical fragrant lacunosa flower.

This species is actually a very robust and free flowering candidate to light up a high rise balcony, provided that at least a couple of hours of morning sun is available.

Wednesday, March 11, 2020

Xerophytic Begonia from Palawan

The northern part of Palawan is a beach bum paradise. It is also dominated by  prominent limestone karsts which understandably see much less human traffic than the beaches. The cliffs are very photogenic and instalgrammable when observed from afar but the treacherous steep slopes can be daunting.

Fortunately there was a cliff which can be accessed through a cave. The stalagtites and unusual geological patterns of the walls were interesting, but they were sideshows. Actually we were also unsure what to expect, we just need to climb some limestone cliff and check out the flora offerings... 

 .... the cave opened into a west facing cliff face and we were blinded by the intense sun.

the first thing I noticed as my eyes acclimatised to the light was high quantity of Dioscorea seed capsules sprayed all over the ground and this Euphorbia antiquorum which can be found all over seaside limestone from Indochina to Malaysia. I remembered saying to my mate not to expect any Begonia in this type of habitat, when he interrupted "looked behind you".....

.... is this a Begonia I see before me .... or an alien ?
Actually its the recently described Begonia elnidoensis which is named after El Nido the beach enclave that is full of beautiful bodies of water and humans. It is one of the most xeric Begonias I have seen. Some Begonias in seasonally dry area will become dormant, leaving behind a tuber in the ground to wait for the next favourable growing season but this Begonia keeps growing even in the dryest season.

Growing on near vertical cliffs, they have more stems than leaves. This being the dry season (there was no rain for 3 months or so) and with little shade from the sun on the vertical cliffs, leaves are very few and the dominant feature was the thick gnarled stems, some longer than 2 feet, growing out and almost perpendicular to cliff faces. Plants supposedly grow on and on - old stems die out but new ones appear from the thick clump. It does not has prominent tuber or caudex. 

Another similar Palawan endemic, Begonia wadei, differs from having a hairy petiole, amongst other characteristics.

At another locality, less exposed and more humid, we saw more leafy specimens with brilliant red-veined leaves, even flowering specimens, which was surprising in this dry period. There are also some seedlings peeping from crevices. The seeds are reported to be dispersed by wind.


Reference  : Hughes, Mark; Peng, Ching-I et al, May 2018, PLoS One 13(5) e194877

    Related Posts with Thumbnails