Re: S. purpurea subspecies venosa variety montana

From: SCHLAUER@chemie.uni-wuerzburg.de
Date: Fri Oct 03 1997 - 14:35:25 PDT


Date:          Fri, 3 Oct 1997 14:35:25 
From: SCHLAUER@chemie.uni-wuerzburg.de
To: cp@opus.hpl.hp.com
Message-Id: <aabcdefg3835$foo@default>
Subject:       Re: S. purpurea subspecies venosa variety montana

Dear Carl,

> I guess this is skeptic in me, however, has anyone done transplant
> experiments to see if its an environmental thing! I'm still trying figure
> out the rationale for venosa and purpurea distinction.

Don Schnell has been doing this kind of experiments for all the taxa
he described with several different clones from several different
populations for more than 20 years (certainly much longer for some
taxa). I guess that should be sufficient even for a most pedantic
skeptic.

> I suppose as human's we have this insane urge to classify things,

While this is perhaps not reasonable where no classification is
justified by the real/natural situation (resulting in artificial
classes), this urge is not insane per se. In fact all sensible human
communication depends on a common classification of things. The
problems of this are only more apparent in those cases where the
rules of naming (of the classes established by the classification)
are rather strict (as in the case of the ICBN), so sometimes the non-
universality of the classification becomes obvious.

> maybe
> instead of splitting hairs on purpureas maybe we should work on some of the
> more obvious plants that deserve status, ie all the green "albino" forms of
> Sarrs. S. purpurea f. heterophylla is formally recognized, where is S.
> rubra jonesii f. heterophylla, S. psittacina f. heterophylla, S.
> leucophylla f. heterophylla etc etc etc.

Well, there is a fairly important difference between taxa (like
species, subspecies, variety, form) and mutants (variants, colour
forms). Of course, both are genetically the result of the same
fundamental process. But while taxa have passed a certain process of
selection, so they can be called adapted to certain environmental
factors, the only selection step concerning colour forms as those
mentioned in your message (with the possible exception of _S.
purpurea heterophylla_) was collection and propagation by an
enthusiast. The latter is an artificial process like breeding. Thus,
these colour forms may be obvious but the only status they deserve is
that of cultivar.

> While I'm on this thought, how about all the alatas, people are splitting
> hairs on purps when alata is more variable than any other sarr!, and yet,
> no ssp, no var's, no formas or anthing of the like.

Seems to be a job waiting for you! However, variability alone does
not warrant any distinction of taxa. Only if you can find a constant
correlation of characters within the whole range of variability with
defined parts (geographic, ecological) of the collective taxon (in
this case _S. alata_), a taxonomic distinction may be reasonable.

> Is anyone planning on giving formal status to the rubras of western
> Georgia, that we all affectionally call Ancestral? What about the mountain
> form of flava that occurs in a number North Carolina mountain bogs?

I have not heared about any such planning.

> Maybe I should write a paper ;-)

This is perhaps not too ridiculous an idea. Some prior discussion
with Don would certainly not do any harm, however.

Kind regards
Jan



This archive was generated by hypermail 2b30 : Tue Jan 02 2001 - 17:31:11 PST