Giant Nepenthes alata

[ayi]

I think the photos below shows how Nepenthes alata experiments and continually takes on myriad forms in order to... what, produce new species? Just see for yourself. All plants were in the same national park.

Healthy plant almost resting on Gleichenia:
[img src="i957.photobucket.com/albums/ae51/ayi_06/DSCF5596.jpg"*][/img*]

A typical, plainly coloured N. alata
[img src="i957.photobucket.com/albums/ae51/ayi_06/DSCF5598.jpg"*][/img*]

More plants:
[img src="i957.photobucket.com/albums/ae51/ayi_06/DSCF5599.jpg"*][/img*]

[img src="[/img*i957.photobucket.com/albums/ae51/ayi_06/DSCF5600.jpg"*]]

The biggest single colony encountered:
[img src="i957.photobucket.com/albums/ae51/ayi_06/DSCF5602.jpg"*][/img*]

Note the very tapered pitcher base:
[img src="[/img*i957.photobucket.com/albums/ae51/ayi_06/DSCF5603.jpg"*]]

Intermediate pitcher:
[img src="[/img*i957.photobucket.com/albums/ae51/ayi_06/DSCF5605.jpg"*]]

A plant with unusually stout pitchers. We could not get close enough to have it examined because of the very crumbly substrates.
[img src="i957.photobucket.com/albums/ae51/ayi_06/DSCF5608.jpg"*][/img*]

Plants of Spathoglottis tomentosa are everywhere:
[img src="i957.photobucket.com/albums/ae51/ayi_06/DSCF5614.jpg"*][/img*]

[img src="i957.photobucket.com/albums/ae51/ayi_06/DSCF5726.jpg"*][/img*]

A large antplant- Myrmecodia tuberosa:
[img src="i957.photobucket.com/albums/ae51/ayi_06/DSCF5687.jpg"*][/img*]

A Strongylodon species with spectacular blue flowers:
[img src="i957.photobucket.com/albums/ae51/ayi_06/DSCF5713.jpg"*][/img*]

About 20 km further up, we came across another N. alata population:
[img src="i957.photobucket.com/albums/ae51/ayi_06/DSCF5757.jpg"*][/img*]

About 3 m to the right of the plant above is this one:
[img src="i957.photobucket.com/albums/ae51/ayi_06/DSCF5747.jpg"*][/img*]
I believe the stout-pitchered plant we saw earlier would be like this one above.

Another plant, with a slightly taller pitcher:
[img src="i957.photobucket.com/albums/ae51/ayi_06/DSCF5746.jpg"*][/img*]

This one also has a quite massive pitcher, but with red peristomes:
[img src="i957.photobucket.com/albums/ae51/ayi_06/DSCF5763.jpg"*][/img*]

Growing nearby it is a plant with slender pitchers:
[img src="[/img*i957.photobucket.com/albums/ae51/ayi_06/DSCF5751.jpg"*]]

This intermediate pitcher is 19.5 cm tall by 6 cm in diameter:

It's upper pitcher is even taller at 21.5 cm, although the girth is also at 6 cm:
[img src="i957.photobucket.com/albums/ae51/ayi_06/DSCF5752.jpg"*][/img*]

[img src="[/img*i957.photobucket.com/albums/ae51/ayi_06/DSCF5764-1.jpg"*]]

The two pitchers side by side; they belong to just one plant:
[img src="i957.photobucket.com/albums/ae51/ayi_06/DSCF5770-1.jpg"*][/img*]

About 2 m to the right of this giant N. alata is this plant with typically shaped pitchers, but with lovely pastel colours:
[img src="[/img*i957.photobucket.com/albums/ae51/ayi_06/DSCF5768.jpg"*]]

And ca. 3 m to the left of the humongous N. alata is this one:
[img src="i957.photobucket.com/albums/ae51/ayi_06/DSCF5760.jpg"*][/img*]
Compare its shape to the uppers of the other plants shown here.

Anyway, a meter below it is this one:
[img src="i957.photobucket.com/albums/ae51/ayi_06/DSCF5748.jpg"*][/img*]

A seedling. Note the subpetiolate leaves; in all other young alatas I have seen from other parts of the range, the leaves are always distinctly petiolate.
[img src="i957.photobucket.com/albums/ae51/ayi_06/DSCF5759.jpg"*][/img*]

There is something strange about the peristomes of the stout ones: always wavy-edged- this character has not been observed in typical alatas. And so, they stand out from the 'normal' ones by virtue of their larger and stouter pitcher size, and wavy peristomes.

[Dave Evans]

I suspect these "stout alata" could be hybrids. Finally, a weird plant that actually looks like it could be the result of introgression from another species...

Besides for the N. macfarlanei, N. ramispina and N. sanguinea mash-up in Malaysia.

Something about the peristomes and lids remind me of N. merrilliana..., but I don't think these plants would actually be related to N. m., just a similarity of shape.

[ayi]

No Dave, there were no other species from the same area that could be regarded as a putative parent.

Regarding N. merrilliana, they have been found on the park- Samar Island Natural Park to be exact- although no formal report has ever been made. Nevertheless, N. merrilliana has been sighted on the southern end of the island, whereas these alatas were encountered on the eastern-central portion of Samar.

[sunbelle]

Amazing, Ayi. At approximately what altitude were you observing these?

[Dave Evans]

Feb 25, 2011 3:16:59 GMT 7 ayi said:

No Dave, there were no other species from the same area that could be regarded as a putative parent.

Right, in a situation that would be regarded an "introgression" you'll be past the point finding pure examples of both species in the same population--one has been absorbed into the other even if only partially. Or, at least all pure example of the second species are no longer present; having died out at sometime in the more recent past.

I really don't think we are looking at stands of pure N. alata, but rather N. alata and another plant that needs more research.

I do see plenty of normal looking N. alata with petiolate leaves... But all the seedlings were sub-petiolate?


BTW, does anyone know if there are Nepenthes on Pilar Island?

[ayi]

I forgot to mention that on one stout-pitchered plant there were tiny hairs on the pitchers and stems; these were absent on similar plants. If a N. merrilliana gene is hovering somewhere within these plants I would guess that indumentum would not be present, considering that the alatas that we have here are the glabrous ones. A look into the lid underside of the green upper pitcher shown above revealed no N. merrilliana characters either.

[img src="i957.photobucket.com/albums/ae51/ayi_06/DSCF5765.jpg"*][/img*]

I have to admit though, that if I found these plants growing as pure populations, I'd be inclined to think of them as a still undescribed species- or a stabilized natural hybrid.

I found some seedlings that have strongly petiolate leaves; I would guess that these grow to be the typical ones.

[img*][/img*]


Pilar Island lies west of Samar, north of Biliran and Leyte. I do not know if there have been a recorded occurrence of a Nepenthes there, although at least one website mentioned in passing a Nepenthes on Biliran; Nepenthes alata occurs on northern Leyte, while N. truncata is on its southern end.

Sunbelle, I would guess around 200 m or less- we are already pretty close to the eastern coast here.

[Delphiguy]

Ayi thanks for sharing this to us... those stout alatas are gorgeous, but I have say they dont
look like alata to me.

[Dave Evans]

I think if it a kind of hybrid, we probably aren't talking about N. merrilliana, but rather something of a similar size which looks rather similar.

www.fieldmuseum.org/vanishing_treasures/Origins_2.htm

I'm fairly sure Nepenthes have been pretty much in the same places for the last ten thousand years or so... With major changes taking place at the highs and lows (new and disappearing habitats) of the iceage cycles. When I look at those maps, I can see how we have ended up with the species ranges as they are now.

I can also see that the individual species have surely have outlived the individual cycles, in order for N. alata to have spread as far and wide as it has, it has to have started spreading at least several ice-ages back.

When we look at the "villosa" group, the founding species must have been present (i.e. already widespread and had been spreading for a long time) when Mount Kinabulu and all the mountain on Palawan rose up. The ancestor probably colonized Palawan as it was coming out of the water. (not sure 20 MYA?) Then this successfully spreading species was broken up by the rise of those mountains, about one million years ago. If they have colonizied other areas, these places have just been covered over by the sea again. As the sea continues to rise, the isolation is maintained.

Total guesstamation: seems like it takes at least 250,000 to 500,000 years for a Nepenthes species to evolve and claim some territory beyond its hatchery. Some, like members of this "villosa group" might not move from their mountains a much longer time frame, if ever.

[ayi]

Interesting views there, Dave. The big question in my mind right now is, when trying to provide a description for Nepenthes alata, where do we draw the line? This species must be speciating faster than any other Nepenthes taxon- it might even be throwing out experiments on itself by trying to see which traits will work on a particular ecological niche.

The absence of another species that can be considered as a putative parent- assuming for the meantime that the robust plants are natural hybrids- and the presence of seedlings that appear different from typical alatas early on in their development might imply that these odd plants are reproducing on their own, even if they may be of hybridogenic origin. I would love to see these populations in flower, to see if there are floral differences, and if they flower at a different time than the alatas.

[leeb]

Ayi,
great to hear that N. merrilliana has been found on southern Samar, presumably on the ultramafic soils there.
Does it differ from the N. merrilliana on Mindanao or Dinagat?

I wonder if N. bellii, N. mindanaoensis or N. truncata will also turn up on Southern Samar as well?

Also the variation in the "N. alata" could be introgression with another species; if the stout form occurs with more normal N. alata in the same area are there intergrades between them or are they totally distinct.

Dave,
the changes in temperature and rainfall patterns as well as the linking and separation of islands with changes of sea level should have been major factors in the evolution of Nepenthes in the Philippine islands.

Also parts of Luzon, Mindanao, Mindoro and Palawan are older than the islands in the centre of the Philippines; which is why they have the most Nepenthes species.
The Nepenthes of Luzon and Mindanao have more recently been able to come in contact as Samar and Leyte emerged from the sea.
I wonder if N. alata, N. merrilliana and N. truncata overlap anywhere in central or South Samar or Leyte; if they do hybrids with the N. alata may occur there.


LeeB.

[ayi]

Hi LeeB,

Follow this link: www.samarislandnaturalpark.org/index.php?option=com_content&view=article&id=14&Itemid=15

There is a photo of Nepenthes merrilliana there, misidentified as N. truncata. Actually, a Filipino botanist specializing in palms already has informed me two years ago that they found N. merrilliana-like plants in Samar.

Be aware that my photos here were taken from the same park, although not in the area where merrilliana was found, or at least have not been found yet. Regarding the stout forms, they occur together with the typical alatas and are separable from them in their larger and differently shaped pitchers, and wavy-edged peristomes. Also, the leaf bases of the seedlings are not as petiolate as the typical ones.

[Dave Evans]

Feb 25, 2011 10:00:15 GMT 7 ayi said:

Interesting views there, Dave.

Well in northern Australia, in appears that as the Nepenthes loose ground to the rising sea three recently developed species are now being pushed back together possibly back into one species...

The big question in my mind right now is, when trying to provide a description for Nepenthes alata, where do we draw the line? This species must be speciating faster than any other Nepenthes taxon- it might even be throwing out experiments on itself by trying to see which traits will work on a particular ecological niche.

Nah, N. alata didn't spread over thousands of square kilometers for thousand of years only to mutate into a new taxon within one generation a few meters from the parent taxa.

I'm very interested to see if there are flora differences too

[leeb]

Thanks Ayi,

that is a nice N. merilliana picture on that site.

If both "N. alata" forms occur together with no sign of intergrading then they are acting as different species even if one of them evolved from an ancestral N. alata introgressing genes from another species.

If the Mindanao N. alata differs from those on Luzon, Leyte and northern Samar then it may well be a different species.
Perhaps it is restricted to ultramafic soils, in which case it might occur with N. merilliana on the south of Samar.


Also, on that website you referred me to there is a picture of another Samar Nepenthes, near the purple orchid flower.
Is that a N. alata?


LeeB.

[Dave Evans]

Well, I can see the leaves are a match for alata and the lid of the pitcher is cordate...

[ayi]

Yes LeeB, that should be Nepenthes alata; in the wild you will often see them growing with Gleichenia ferns on a variety of substrates (on Samar they have been found growing on solfatara), even on lava flows with N. ventricosa.

As of now I am inclined to accept Dave's view (and yours too) that the larger-pitchered Nepenthes might be a different species. It doesn't matter if it's of hybrid origin, as it seems to be capable of producing progeny with stable characters; our current views on N. hurrelliana and N. hamiguitanensis should back this up.

As I do not discount the possibility of them being hybrids, I am now curious to know what the other parent species could be, and if they still occur somewhere not far from where they are.

I am now just waiting for the Mindanao 'alatas' to flower, as we have several vining plants already.

Ayi