Date: Fri, 2 Jun 2000 19:56:54 -0400 From: "Dave Evans" <dpevans@rci.rutgers.edu> To: cp@opus.hpl.hp.com Message-Id: <aabcdefg1696$foo@default> Subject: Re: sabah pitchers
Dear gma,
> and should anyone check this ref out, you will see a picture on page 18 of
a
> n. vietchi climbing a tree. it does so by the leaves growing around the
> trunk of the tree and hooking the pitcher of the opposing leaf. i cant
> understand how it could grow in this fashion which seems to imply a
'spatial
> awareness' in the plant (which i believe is unknown). if anyone can
explain
> this odd growth habit, please enlighten me. i grow weary trying to figure
it
> out.
> gma
Nah, there is not an awareness per say, but rather it's the shape of the
leaves which is in turn controlled by hormones which are in turn partially
controlled by the way gravity interfaces with the stem and vascular system
of the plant. If there is no tree the plant assumes a different shape, but
not all that different. The leaves still curl backward and the plant will
continue to grow leaves in opposite pairs as if it expects there to be a
tree to hug onto. The leaves of _N. veitchii_ naturally try to mold
themselves onto the surfaces they encounter. My veitchii once grew a leaf
into the root ball of an orchid. It tried to hug onto every root it
encountered and resulted in a very reduced leaf blade width, which was bent
every which way, but the leaf grew to normal length and produced a nice
pitcher. If they had an awareness, they would go for the nearest tree, but
they don't they just make do with the surfaces they encounter. I wonder,
are there any other plants that use this sort of molding of the leaves to
hold onto surfaces? I know tendrils of many, many plants do this, but the
actual leaf blade? Oh, you know, I have never seen the tendril of _N.
veitchii_ wrap around a hold. Perhaps this ability got transferred from the
tendrils to the leaves in this species....
Dave Evans
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