Re: SPEC: I. lazica and I. cretensis

>Dear Sir,
>
>How can I be sure that I. lazica is a form of I. unguicularis and not a
>species of its own.
>
>Would you please tell the reference?
>

Although in many older references, both lazica and cretica are considered
forms of unguicularis, the BIS species book lists lazica as a good species,
and cretica forma latifolia as a synomym of lazica.  Iris cretica is split
by the authors, with some forms as synonyms of unguicularis (a subspecies
I. unguicularis cretica is recognized), and some of lazica.  Aaron Davis
and Stephen Jury, the authors of the account of Series Unguiculares, say:

"This species [I.lazica] is easily separated from I. unguicularis by its
flat, wider, more or less unribbed leaves and larger fiddle-shaped falls.
It also occupies a completely different ecological niche."

And elsewere:

"Although I. unguicularis prefers a hot sunny position it must never be
allowed to dry out completely; for this reason we prefer to see plants
grown out of pots with an unrestricted root run.  Iris lazica grows in an
area of much higher rainfall and lower winter temperatures and is therefore
more tolerant of life in British gardens.  This species can grown in the
open garden in any good, fertile soil."

For this point of view see also:

Davis, A. P., & S. L. Jury.  1990.  A taxonomic review of Iris L. series
Unguiculares (Diels) Lawrence.  Botanical Journal of the Linnean Society
103:281-300.

Having said all that, we have to keep in mind that there are two kinds of
taxonomists (broadly speaking): splitters and lumpers.  Splitters, in the
extreme, recognize "too many" species by considering each variant a
species, whilst "lumpers" recognize "too few" by assuming that much of
observed variation does not reflect speciation.  However, those are
extremes.  Most taxonomists are somewhere along a spectrum between the two
extremes.  Taxonomic views on species status are usually settled by
concensus, after numbers of specialists in the group in question have
viewed the evidence and expressed their judgement.

It seem to me that for now Davis and Jury are on sound footing for
recognizing two species in Unguiculares (as opposed to the half-dozen or so
that have appeared in the literature).

Now--my plant of I. lazica, which was purchased from Arrowhead Alpines,
looked just like unguicularis when it bloomed, and not like the description
given by Davis and Jury.  Iris cretensis in my garden is clearly a form of
unguicularis.  The plant came from Dennis Kramb, who got it from a friend
in Greece (please correct me if I am wrong, Dennis).

So I was being hasty and probably wrong in making the blanket statement
that both cretensis and lazica are forms of unguicularis.

Plants in cultivation may be mislabelled, and trading can perpetuate and
spread the error.  Iris minutoaurea is in commerce, but it has been pointed
out that much of what is distributed as that species in Britain is a
non-blooming dwarf Acorus graminea.  Jim Waddick showed in the most recent
SIGNA that a new Korean species was just a typical I.sanguinea.  Several
years back, seed of "I. koreana" was distributed by SIGNA and on blooming,
the plants also proved to be I. sanguinea.  I bought "I. ruthenica" from a
heretofore reliable supplier, and it was (is there a pattern here?) I.
sanguinea.  So among we gardeners a great deal of confusion can arise if we
simply take at face value the labelling of plants in commerce.

Sometimes garden writers inadvertantly coin "new" species. In a recent
message I drew attention to famed perennials expert Alan Armitage referring
to something called "I. louisiana," a name that has never been used before
and does not refer to any known iris.  Alan (otherwise very reliable and a
terrific writer) also pictured I. cristata and labelled it I. tectorum,
'Colorific,' and advanced generation Lousiana Iris hybrid, and labelled it
I. nelsonii, and finally, called an obvious form of I. setosa a Siberian
hybrid.

So before we gardeners condemn botanical taxonomists for causing confusion
in our ranks, we should cast the beam out of our own eyes!


Bill Shear
Department of Biology
Hampden-Sydney College
Hampden-Sydney VA 23943
(804)223-6172
FAX (804)223-6374
email<wshear@email.hsc.edu>
Moderating e-lists:
Coleus at http://www.egroups.com/community/coleus
Opiliones at http://www.egroups.com/community/opiliones
Myriapod at http://www.egroups.com/community/myriapod
Other Mailing lists | Author Index | Date Index | Subject Index | Thread Index