Winged tendrils

[Dave Evans]

Dear Forum,

I have taken part in discussions about why some Nepenthes, like N. rafflesiana and N. mirabilis have winged tendrils.

I have heard that perhaps the plant is evolving a second pouch-like structure to catch more prey. However, I rather doubt evolution is so forward thinking... It seems like the plants would have to have made a plan about how they want to evolve for this theory to work.

One reason I haven't seen postulated is because they share a common ancestor which did have this trait, perhaps as a 'throw back' to a time when Nepenthes did not vine and didn't necessarily need tendrils.

This seems especially evident when reviewing seedlings of these two species--there is no ending of the leaf before the pitcher starts. The edges of the leaves are directly connected to wings on the pitcher and most species may show this on the first two leaves, or not even show this trait at all; N. rafflesiana and N. mirabilis continue to show this trait for several leaves and on N. r. up to six and counting...

Basically, it seems to me this is a trait of these two species, not so much a trait of specific plants with names like "var. alata".

I wonder what other species have winged tendrils? Ever see this on Nepenthes from Phang Nga (viking)?

[shawnintland]

Hi Dave, Yep, I was just looking at one of my vikings yesterday that has the same thing. It didn't continue very far up the tendril but only the first 2" or so, but still made a very unique look. Unfortunately 'something' got in the shade house and munched away at the pitcher so I didn't bother to photograph it. Will shoot it on the next pitcher.
~Shawn

[rsivertsen]

I always regarded this as a "throw-back" feature to a time before Nepenthes developed functional tendrils, and the pitcher was just on the bottom part of the leaf/petiole. Another consideration is that it may serve to increase it's photosynthesizing surface area, which would help in those darker, denser forest floor places. Still another possibility is that these things may help to store water for the developing pitcher bud when they form small pockets just before the pitcher forms and curls upward. - Rich

[shawnintland]

I had a few minutes to spare and the camera in-hand so here's the 'next' pitcher on the Viking,


(and the bug-eaten one!)

Also spotted a wavy-winged tendril-ed "thorelii" but had already left the camera at the computer... next time!

~Shawn

[Dave Evans]

On another forum, I posted the same thread and someone mentioned that this also happens in N. neoguineensis.

I'm posulating these four species: N. rafflesiana, N. mirabilis, N. neoguineensis and sp. Phang Nga all share a closer common ancestor which contributed this trait into them--not the ability to have winged tendrils which all Nepenthes probably possess, but that production of these wings on the tendrils haven't been more completely turned off genetically in their lineage.

[shawnintland]

Well, this won't throw off your postulation any; viking x 'thorelii'


and a pretty front end too;


I'd kind of like to find a way to switch it back 'on' in some other species myself!
~Shawn