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Borneo Trip - 2009

Borneo Trip - August 2009
In August 2009 fellow Nepenthes enthusiasts,  Richard Nunn,  Greg Bourke and myself travelled to Sarawak in Malaysian Borneo. We planned and successfully climbed Mt.Tambuyukon, Mt.Trusmadi and also walked up Mt. Alab and visited the N.rajah site at Mesilau. My main reasons for doing the trip were to see the magnificent N.edwardsiana and N.macrophylla in the wild. I was not disappointed!
There has been much speculation on the Nepenthes' forums on what a true N.macrophylla was and I wanted to actually see how much variation there actually was in the species in the wild.
Below is a mainly photographic, account of the trip.

Mt.Alab

                                               N.fusca

  N.chaniana - I believe this is the type                             N.tentaculata 

 as it has the markings on the pitcher.                                                          

               Another N.tentaculata colour form.                            Tentac. country

                                         Some Bornean locals!

             Some local Bornean accomodation                     Our next stop. 14km at 45-60o angle and 35oC!

       

We were a bit late starting our trek and it was 11am and 35oC with high humidity. It took it's toll with some forced early stops. However after a little rest and re-fuelling we made good time in the heat but welcomed the cooler temps in the forest as we climbed in elevation. I was very surprised at the dryness of the surrounding forest even as we climbed higher. The leaf litter was at least ankle high with some of the huge leaves over a metre long!

                                                               Some welcome relief!    

                

            Alocasia cuprea                                                        Steep track      

    

    To think, they cut these down!                                  N.burbidgeae          

                       

               N.burbidgeae                                                N.tentaculata - Mt.Tambuyukon

We reached our second camp on Mt.Tambuyukon at dusk and thankfully it was cooler but still quite dry. However mist started to roll in as the sun set which helped with the cooling and to increase the humidity. It still didn't look like highland Nepenthes habitat but it was looking closer. We were at around the 10km mark. The night was cool but definitely not cold. Early the next morning after another great meal our guides prepared for us it was after more Nepenthes. The first we came accross was N.burbidgeae and close by N.tentaculata. These were not far from the camp but the mountain rose quickly from that spot. I was taken with the variation in N.tentaculata colouration from mountain to mountain. They were easily distinguishable as the species but the range of colour and markings varied. I was still quite surprised at the lack of moisture in the surrounding forest. N.tentaculata were growing in exposed damp patches at the base of trees and along the edges of the track but N.burbidgeae were growing in quite a lot of shade in the under growth and from what we could see, very few were climbing.

A bit further up the mountain, one of my main reasons for coming to Mt.Tambuyukon started to appear, N.edwardsiana!

                                    

Words and pictures only give one a glimpse of this magnificent species! At first we came across one small plant but as we climbed they were everywhere and very large. Some moss forest started on the logs and trees off the side of the tracks but it was still quite dry and most of the plants were growing epiphytically in very coarse dry moss on the tree trunks.  They had surprisingly small root systems for the size of the plants. In my observation, from the tracks and surrounding forest, the N.edwardsianas started to peter out at the 12km mark but Greg said there were some up further, on exposed ridges. I did not go right to the top but chose to stay amongst this magnificent species to observe and record as much as I could.

               

                                      Their epiphytic habit. Note the coarse species of moss.

            

                  N.edwardsiana habitat.                                        An upper pitcher

                      

                               Lower pitcher                               The amazing peristome.

     I reckon this species should be the 'King of Nepenthes'. It comes with its own crown as well!

                           

                            

                                                    How big do they get. THIS BIG!!!

                        

                                                      Their amazing peristome!

                         

                                                                                                   Rear view.    

                   

           My thumb in between the peristome ribs!

It was a hard mountain but worth every step. N.edwardsiana is just an amazing species.  There has always been a lot of discussion and speculation on the purpose of the huge teeth on the peristome of this species but observing the plants for many hours I have my own theory. As I stated, the mountain was very dry, in fact it did not rain at all in the 5 days we were there! This is apparently common in the annual dry season. While observing the plants, I noticed that a lot of the upper pitchers had holes pecked in them, just below the fluid line. Obviously birds or small climbing animals knew them to hold fluid and used them as a water source. I thought that maybe they were after the pitcher contents but I did not see many insects in them. I never observed any holes right on the bottom of the pitcher which would have drained it entirely but 0ones just below the fluid line. Yet all the pitchers I looked in still had fluid in them. As the lid deflects a lot of the water coming from the rain and there obviously had not been any rain for a while, it got me thinking about where the fluid would come from to top the pitchers up after it looked like it was being consumed. This lead me to thinking about the peristome teeth and the way they point into the pitcher and knowing that plants such as African violets, are covered with hairs and these collect the water that condensates from the fog that covers there habitat in the evening etc. and I theorised that this may be the purpose of the teeth! They are vertical, have a large surface area compared to the peristome and therefore increase the peristome's surface area. The fog would condensate into droplets on the teeth and the droplets would build up and eventually run down into the pitcher! It would also work in reverse in the wet season with constant heavy rain and wind, in that the teeth would cause heavy rain drops that the lid cannot deflect, to splatter and break up causing more of a spray and therefore deflecting it. This would stop the pitchers from filling and emptying their contents.

 Some more support for my theory...

Also, it can be seen that a lot of the peristome is outside the mouth area of the pitcher and in my opinion, this leads to more evidence for my theory. I say this because with the constant high humidity and the continual temperature fluctuation from day to night in the highlands and therefore daily high condensation, if the teeth were mostly over the mouth there could be too much fluid collected in the pitcher. With the continuous rain in the wet season, having most of the teeth deflecting the rain and it running down outside the pitcher would also make sense too as it again would stop the pitcher filling. This adds up from what I observed in that the pitchers all had normal fluid level in them or the ones with the pecked holes were just under.

There has always been the theory going around that the large teeth were to keep large prey from escaping from the pitcher. However, if the prey were large enough to escape they would just tear the pitcher open. If the captured prey was not strong enough to tear the pitcher and could climb the slippery internal pitcher walls, it would have to negotiate the inward overhanging part of the peristome. In this case the teeth would be irrelevant as they are on the outside of the peristome and most Nepenthes pitchers have the same basic peristome construction. Therefore, to me, along with the lack of prey I observed in the pitchers, this does not explain the reason for the large raised teeth in this species. I know N.hamata has similar teeth on its peristome but not having observed this species in habitat yet, I cannot say if its teeth serve a similar purpose.

Just a theory!

This is part one. The next part is Mt.Trusmadi.

 

 



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