Re: Ibicella lutea: Carnivorous or not?

Date: Mon Feb 01 1999 - 19:21:33 PST

Date:          Mon, 1 Feb 1999 19:21:33 
Message-Id: <aabcdefg286$foo@default>
Subject:       Re: Ibicella lutea: Carnivorous or not?

Dear Chris,

> Also Ivan has been recently
> doing experiments on Ibicella and Proboscidea and he claims at least
> Ibicella is only carnivorous

How did he test carnivory?

> in high humidity settings. He claims the plant will secrete enzyme

It secretes mucilage. There may be enzymes in this liquid but none
of which has been found to have digesting activity. Did Ivan find
such activity? Please remember that moulds and bacteria will be
encouraged to grow in a humid environment. So it would probably be
the best to use sterile plants from in vitro culture.

> around an insect or digestible matter in high humidity
> meaning that it probably works in the wild like Byblis where it is actively
> carnivorous primarily during the morning hours when the morning dew is out.
> Jan, have you grown the plant and tested it yourself yet?


> 2 or 3 experiments
> isnt a good deal of testing to conclusively prove something especially if
> humidity is a factor which was unaccounted for.

The plants I have tested (with more than 2 or 3 experiments, even
with pieces of the leaves actually immersed in water, which should
provide quite a deal of humidity) were grown in a comparatively humid
environment, supposedly in a more humid one than will be encountered
at its native habitat in Argentina (and surrounding countries).

Barry Meyers-Rice and Jon Wallace & al. have conducted slightly
different experiments under their respective growing conditions with
the same objective to find evidence for digestive activity. All with
negative results. This is IMHO significantly more experimental data
than ever published before.

> I'm not a 'true believer'
> that is plant is carnivorous as I might sound but I do think that other
> factors need to be accounted for

OK, it's your turn, convince me by accounting for whatever "factors"
you like, as long as your conclusions are based on facts. But
please do not just cite the time-honoured 1915 paper once again.

> before we draw a rigid conclusion.

I would not recommend to draw any rigid conclusions here. What we
are talking about are hypotheses. Experiments are designed to test
these hypotheses, and to improve them accordingly. There will
(hopefully!) never be a "final truth" of plant carnivory.

Be always prepared for the unexpected!

Kind regards

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