Firstly this plant also possibly occurs on G. Kinabalu but is usually
thought to be just a giant form of N. tentaculata and it is not common.
If N. murudensis really is a hybrid between N. tentaculata and N.
reinwardtiana why does it grow commonly over such a large area of this
mountain? Perhaps the "hybrid" on this mountain is more successful than
either parent over its altitudinal range and habitat type. Thus you could
come to the conclusion that it may be differentiating into a new species,
especially if neither parent is really suited to this habitat and there is a
lack of competition. In effect it has found it's own niche.
Also the N. sp. maxima/veitchii/fusca species in this book is another
good example of this type of evolution. Perhaps this area was lacking in
Neps in the past and a hybrid filled the gap. As well as those sites
mentioned around the Sarawak/Sabah border, it also occurs on G.Pagenprick in
Brunei at similar high altitudes. This new "species" occurs on the edge of
all 3 previous species ranges.
Another plant to think about is N. ephippiata. Doesn't it look a bit like
a hybrid between N. lowii and N. rajah (or some other ancestor)? This is
not entirely improbable as N. lowii does grow on many mountains along
Borneo's spine. And just look at its huge geographical range from G. Raya in
South Kalimantan to B. Batoe Lesoeng in the East and also probably other
unexplored mountains nearby. Perhaps it differentiated earlier than the
afore mentioned plants and had also found an area when no other competition
existed.
This lack of competition effect is well illustrated in New Guinea where
N. maxima has taken on all kinds of shapes and sizes. A huge area of habitat
along with no competition has allowed this species to show its full genetic
potential.
Also consider N. hookeriana. I have seen this species/hybrid in Indrapura
on Sumatra's West Coast. Here it grows abundantly on scrubby banks with only
a few N. ampullaria to be found but no N. rafflesiana. Here again we find a
"hybrid" that is beginning to stand on it's own.
These are just a few thoughts I had. Now I'll stand back and see what kind
of Hornets nest I've stirred.
Bruce Salmon
Another thought....
N. villosa, N. edwardsiana and N. macrophylla are so closely related
that
they have been combined in the past (obviously they have a common
ancestor). Why are they now separate species? Why not call them
subspecies? This species/subspecies deal seems to be an arbitrary
decision when it comes to Neps.