Botanical nomenclatural query

Moore, Gerry gerrymoore at BBG.ORG
Wed Apr 3 10:43:58 CST 2002

I am hesitant to continue this thread, described as "extraordinary" fourteen
or so posts ago by John McNeill.  However, the overview below on the use of
nom. nov. in botanical nomenclature may help explain why the ICBN permits
(but does not recommend) the replacement of a name of a taxon when its rank
is changed.

Summary of when a nom. nov. may be used in botanical nomenclature

1. To replace a name that is illegitimate. This is common.

Ex. 1 under Art. 7.3 in ICBN: Myrcia lucida McVaugh was published as a nomen
novum for M. laevis O.Berg (1862), an illegitimate homonym of M. laevis
G.Don (1832).

2. To replace a name whose epithet cannot be transferred without creating an
illegitimate name. This is common.

 Ex.: Rosa Guaglianone (in Darwiniana 39: 321. 2001 [2002]) when elevating
Rhynchospora gigantea var latifolia H.Pfeiff. to specific rank published the
nom. nov. R. pedersenii because the name "R. latifolia" was already in use
(R. latifolia (Badw. ex Ell.) W.W.Thomas).

3. To replace an existing legitimate name that could be transferred without
creating an illegitimate name but which the ICBN does not require transfer
of the epithet. This is rare.

Ex.  Fernald (in Rhodora 11: 114. 1909) published Arenaria peploides var.
robusta as a nom et stat. nov. for Adenarium maritimum Raf (1836).  The
epithet "maritima" was available at the rank of variety but Fernald chose to
introduce a new name because the name "maritima" had been used at the
specific level under Arenaria and "would be quite meaningless for a local
variation of a uniformly maritime species."

The ICBN examples cited by Guy Redeuilh involve replacing or avoiding
creation of illegitimate names (Nos. 1 and 2 above) because these are the
common cases.  No. 3 above (the rare case) is a "cost" of limiting priority
to rank, and I am not bothered by the lack of a clear example of this in the
Code since it is so rare. Also, it should be kept in mind that there are
"benefits" to limiting priority to rank.  For example, the earliest name for
Magnolia grandiflora L. (1759) is M. virginiana var. foetida L. (1753).  If
we did  not limit priority to rank then the widely used Magnolia grandiflora
L. would have to be displaced with M. foetida (L.) Sarg.  The ICBN buffers
against abuse of the No. 3 example above via Recommendations (e.g., 21. B.3,

I believe the relevant Articles (especially 7.3 and 11.2) when taken
together make it clear that the nom. nov. concept is not limited to cases
involving illegitimacy. And I will drop it there.

Gerry Moore
03 April 2002

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