Re: Name that Sarr.

Date: Mon Nov 15 1999 - 10:16:12 PST

Date:          Mon, 15 Nov 1999 10:16:12 
Message-Id: <aabcdefg3848$foo@default>
Subject:       Re: Name that Sarr.

Readers not interested in nomenclature, please skip this message.

Dear Marcus et al.,

Please, let me comment on the usage of the terms "valid" and
"accepted", concerning the names of plants. The two are frequently
used in a similar way but there is a significant difference.
We have had similar discussions here in the past, but some new
subscribers have joined in, and your recent statement indicates that
some clarification might be useful in order to prevent confusion.

You wrote:

> S. alabamensis is an invalid name of S. rubra ssp. alabamensis.

when you meant "The *accepted* name for _S. alabamensis_ is _S. rubra
subsp. alabamensis_."

A scientific name for a plant is *valid* if it was published according
to the rules of the International Code of Botanical Nomenclature
(ICBN). This has nothing to do with the taxonomic status of the
corresponding plant.

A name can be a later synonym (a name that is not *accepted* because
an earlier, *accepted* name exists for the plant) for two different

1. Another *valid* name has been published earlier for the *same*
plant (i.e. the earlier name was based on the *same type* specimen).
Synonyms based on the same type are called *nomenclatural* synonyms.
They are *invalid* because they violate the rule of priority in the
ICBN. *Invalid* names cannot be *accepted*.

2. Another *valid* name has been published earlier for a *similar*
plant considered by a taxonomist to belong to the same taxon (i.e.
the earlier name was based on a *different type* specimen). Synonyms
based on different types are called *taxonomic* synonyms. They are
*valid*, but their *acceptance* depends on the judgement of a

The example _S. alabamensis_ falls into the second class. It is
considered a taxonomic synonym of _S. rubra_ by D.E.Schnell. Because
there are differences between the types of the two taxa (but not
sufficient ones for specific segregation), the alabamensis-taxon is
recognized (by D.E.Schnell) as a subspecies different from subsp.
_rubra_. This is the view by *one* taxonomist (plus several others
who follow him, including myself). Another taxonomist (L.Mellichamp,
plus the taxonomists who follow him) *accepts* _S. alabamensis_ as a
species distinct from _S. rubra_.

So you see *acceptance* of names is determined by both *validity* and
taxonomic judgement in some cases, while *validity* only depends
on the rules of the ICBN. In order to reflect this situation, I have
marked all *invalid* names (names that cannot be *accepted*
irrespective of taxonomic reasoning) in the cp database with a "~".
All *accepted* names are marked "+". All remaining names (with
the exception of cultivar names, to which different rules apply;
ICNCP, see pertinent discussions in the archives of this list) are
*valid* but not *accepted* in the current version of the database
(but they might be *accepted* by other taxonomists).

Kind regards

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