Cobra lily tongue not needed for luring prey

[sokkos]

Came across this article in this month's issue of the American Journal of Botany while I was looking for something else. Thought you guys might be interested. I copied a portion of the abstract below from the journal site.

www.amjbot.org/content/103/4/780.abstract

TITLE: The cobra’s tongue: Rethinking the function of the “fishtail appendage” on the pitcher plant Darlingtonia californica

PREMISE OF STUDY: Carnivorous pitcher plants employ a variety of putative adaptations for prey attraction and capture. One example is the peculiar forked “fishtail appendage”, a foliar structure widely presumed to function as a prey attractant on adult leaves of Darlingtonia californica (Sarraceniaceae). This study tests the prediction that the presence of the appendage facilitates prey capture and can be considered an example of an adaptation to the carnivorous syndrome.

KEY RESULTS: Removal of the fishtail appendage did not reduce pitcher leaves’ prey biomass nor alter their prey composition at either the level of individual leaves or entire populations. Fishtail appendages on plants growing in shaded habitats contained significantly greater chlorophyll concentrations than those on plants growing in full sun.

[danyoh]

Saw this recently. Very interesting read

[therobinmonster]

Pretty cool article !

[Apoplast]

Hi Sokkos - Yes, saw that. It was even the cover photo. It was a good test that the "fish-tail" on Dars likely has noting to do with the trapping proficiency of the pitchers. I've not yet gone through the full article, but the chlorophyll concentration is interesting. Typically, I think of chlorophyll concentration as increasing in higher sunlight. I'll be curious if they measured other correlated traits such as leaf-mass-area. Interesting results though, thanks for sharing the article here!

[sokkos]

I saved the article but haven't gotten around to reading it yet. Perhaps under lower light there is less insect prey so the plant has to compensate? Chrlorophyll is a nitrogen sink and nitrogen may be limiting, so rather than increasing chlorophyll throughout the whole leaf, maybe its more efficient to only increase it in the fish-tails since they extend outwards and increase surface area for intercepting light?

[Apoplast]

Hi Sokkos - Interesting hypothesis. However, I would suspect that if there was less insect prey in the shaded plants (though the shaded plants didn't seem to emerge from the analysis for reduced prey items given that was a metric) those plants would have less N available to up-regulate chlorophyll. Great discussion though! I'll read the paper tomorrow. Once you have a chance to, I'd love to hear your impressions.