Re: More on Nelson and Casper

From: Michael (chambe58@pilot.msu.edu)
Date: Thu Jun 18 1998 - 12:38:39 PDT


Date: Thu, 18 Jun 1998 15:38:39 -0400
From: Michael <chambe58@pilot.msu.edu>
To: cp@opus.hpl.hp.com
Message-Id: <aabcdefg2093$foo@default>
Subject: Re: More on Nelson and Casper

At 09:22 AM 6/18/98 -0700, you wrote:

>> Also Nelson states 'To designate the variant with a white
>> corolla as a variety is extravagant' would you care to
>> comment on this statement Jan?
>
>This is a matter of opinion. The only rules for infraspecific taxa
>are those of inclusivity:
>A species may include several subspecies, varieties, and/or forms.
>A subsp. may include several vars. and/or ff.
>A var. may include several ff.
>A f. cannot include several vars., subspp., or spp.
>A var. cannot include several subspp. or spp.
>A subsp. cannot include several spp.
>
>What is a subsp., var. or f. is not defined anywhere in the ICBN
>(OK, they are infraspecific ranks, but not even the meaning or
>significance of this fact is explained to any sensible degree).
>BTW: Yes, Michael, Stuessy writes a lot. But unfortunately (or
>rather, fortunately?) Stuessy is not a collection of rules that
>*must* be followed but only one of the numerous possible *opinions*.

Yes, the ICBN states the rules of nomenclature (the proper application of
names to taxa), but the ICBN does not elaborate on how taxa are to be
defined. I think Mr. Wix's discussion concerns the issue of whether it is
reasonable to define anthocyanin-lacking mutants as taxa.

Stuessy's _Plant Taxonomy_ is a text which offers a modern (well, 1990) set
of guidelines (yes, not rules as such) about these matters (the ICBN does
not). Stuessy's book is not the only such text. If you are prefer other
text(s) dealing with these issues, help educate us by elaborating! It is
important for CP hobbyists to know that botanists HAVE dealt with the
tricky issues of how to define species, varieties, etc. and have
constucted, published, made available, some general guidelines for
researchers. Every researcher does not need to re-invent the wheel on the
basis of opinion!

I believe that circumscription of taxa is a matter of interpretation,
rather than opinion or "taste". Interpretation requires data. Opinions
and taste do not require data (and IMHO more often refer to the practice of
favoring aesthetics over data! :-)

Michael



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