Re: Anthocyanin free Darlingtonia - nomenclature

From: Mellard, David (dam7@cdc.gov)
Date: Tue Jan 20 1998 - 11:54:00 PST


Date: Tue, 20 Jan 1998 14:54:00 -0500
From: "Mellard, David" <dam7@cdc.gov>
To: cp@opus.hpl.hp.com
Message-Id: <aabcdefg253$foo@default>
Subject: Re: Anthocyanin free Darlingtonia - nomenclature


>I therefore maintain that anthocyanin albinos (which are known in
>almost any anthocyanin-containing species) do *not* have any
>taxonomic relevance, as long as they do not constitute separated
>populations that behave ecologically and chorologically independently
>from their ancestral taxon. They can be of horticultural value, but
>this is no taxonomic issue.

Hi Jan and list members,

This conversation has probably already passed me by since I've been out
for a week but since it's one that interests me greatly, I'd like to ask
a question and point out an observation from my bog.

Your point about combining morphology and ecology sounds logical and
reasonable. I'm surpirsed sometimes to read that some taxonomists base
their decisions just (or maybe I should say predominantly) on morphology
when looking at a specimen and deciding where it fits in the taxonomic
scheme.

Applying your ideas mentioned above, is it right to assume that S.
purpurea purpurea f. heterophylla is a distinct taxonomic entity because
it predominates in some wild populations of S. purpurea purpurea?
Whereas, in other Sarr species with the occassional anthocyanin-free
variant in a wild population, such designations are not warranted?

Now, I'll add a superficial observation from my outdoor bog. The lone
S. purp purp f. heterophylla seems to be in better shape than S. purp
purp and S. purp venosa that are growing in the same outdoor conditions.
The purp purp and purp venosa species have a few pitchers that are
weathered and probably no longer functional while the f. heterophylla
pitcher's are in perfect condition. It may be that it's in slightly
more protected position in the bog or maybe the lack of anthocyanin
allows the chlorophyll to be more efficient at producing energy for the
plant.. To end up predominating in a wild population the anthocyanin
free mutant must have some type of ecological advantange, which ends up
being the justification for giving it taxonomic status.

David



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