David; Well said, I did not have time to give the explanations I
perhaps should have. This spring I had a number of the germanica group
that I aquired last fall, bloom for the first time. As time allows I
will post a few pictures. I would like to get my hands on as many
clones said to be germanica as possible. Blooming in the same garden
can allow for closer comparisons than those that have been published.
As I learn I will be filing notes and imagesÂinto the information in
the Iris encyclopedia and would hope that others will do so also.ÂLike
wikipedia we can develop a wonderful storehouse of observations and
data. Since I am no longer trying to create a printed Iris encyclopedia
I am concentrating my efforts on this new online version. At present
what is there, is still generally pretty crude but I have hopes that
many Iris scholars will join in the fun of creating this archive of
information. It is still so crude I would be embarassed to show it to
Brian (Mathew)Âbut I would love to get his comments once it is further
refined. I doubt that my friend George Rodionenko will get to see it
but perhaps his students will find it interesting and be willing to
participate. I look upon the Iris encyclopedia as a meeting place for
all Iris research, while still being useful to gardeners.
To expand on Bob's explanation a bit.
Â
The majority of wildÂbearded Iris species in Europe andÂwestern Asia
(not including the Aril and Regalia groups) have a base chromosome
number ofÂ12 (the number of one set of chromosomes). Most of
these are diploid (meaning they have a single pairÂof sets with 24
total). This is the lowest number possible for most of this group.Â
Some (including I. croatica) are tetraploid and have 48). Most of the
tetraploids are from warmer/drier climates to the south of Europe and
in the Near East. Probably all of these with 12 as the base (haploid)
number can be crossed with one another rather easily, but the
triploidsÂproduced when a diploid is crossed with a tetraploid (with 36
chromosomes) tend to have problems with that odd set when they try to
reproduce, so tend to be sterile, or only by chance occasionally
produce gametes (ovules and pollen) that have a proper number of
chromosomes to pair up with that from other plants.
Â
The tetraploidsÂmostly tend to resembe one another and also I. x
germanica, andÂmost have been lumped by some under that name. However,
really there are several distinct looking populatoins within this
group, and each probably represents a goodÂ"real" naturally occuring
species. I croatica is one of these wild types, but with a few others
such as I. aphylla, it doesn't really fit into the I. germanica
concept, even in the broad lumped together sense. These "others", have
a very different look about them, and I would eliminate I. croatica
from the I. x germanica discussion right here.
Â
The taller/larger species of these tetraploids (hard to say how many
are truly distinct and how many are regional variations of the same
thing) look like the older Tall Bearded cultivars, and along with Iris
pallida and Iris variegata (both diploids) they are the main ancestors
of most of the BB and TB Iris cultivars that we now grow. However,
some breeders add genes from other wild species to the mix all the
time, and some of the classes (but more those smaller than BB and TB)
become more mixed every year. A few of the wild tetraploid types most
important in early breeding of Tall Bearded Iris include I. cypriana,
I. mesopotamica, I. trojana, and I. 'Amas' (= I. amasia, apparently an
invalid name, but I. varbossiana seems to be the same species, and the
cultivar 'Amas' should probably be I. varbossiana 'Amas').
Â
There is also a groupÂofÂwildÂbearded Irises that is different and has
a base chromosome number of 8. These are all dwarf species from
basically near the north coast of the Mediterranean, and they are the
ancestors of most of our "Miniature Dwarf" and "Standard Dwarf" Bearded
cultivars. Those that are diploid have 16 chromosomes, and those that
are tetraploid have 32 chromosomes. Most cultivatedÂMDB and many SDB
Iris have 32 chromosomes and are this ancestry.
Â
Now then, I. x germanica (what is supposed to be the "true" germanica)
has 44 chromosomes (give orÂtake one or two). This seems to be [12 +
12 + 12 + 8), and is derived from crossingÂaÂ48 chromosome parentÂwith
a 32 chromosome parent to get a 40 chromosome Standard Dwarf Bearded
type thing with 40 chromosomes (which functions basically as if it is
diploid, but it basically has now combinedÂtwo sets of 8 with two sets
of 12 to get aÂtwo new (functioning as)ÂhaploidÂsets of 20, yet there
are still 4 sets present). There are a fewÂwild
reproducingÂpopulations of Iris with 40 chromosomes, such as I.
marsica, that are of this same make-up. ApparentlyÂone of these hybrid
"40's" back-crossed with aÂspecies with 48 chrosomes (it seems to have
happened several times to give usÂancient cultivars such as 'Albicans',
'Florentina', assorted "germanicas" and others). It is not clear
which parent species were involved (perhaps mostly I. varbossiana types
which grow in Turkey and nearby and I. pumila, which grows mostly
further west, or perhaps several species, or even perhaps different
species for different individual clones) , but it should be possible to
figure out by comparingÂDNA. Anyway, the resulting "44's"Âseem to be
vigorous plants that have been divided and spread around by humans for
centuries, particularly in the Mediterranean region, andÂseem to have
been carried to the Americas (at least South America) by the Spanish
early on. These 44 chromosome hybrids (functionally they are
tetraploids with one mismatched set of chromsomes) can reproduce, but
because of that mismatch set of 8 in their makeup, the
chromosomesÂdon't behave properly during meiosis, and the fertility
seems low when seeds are produced. Even so, most can make some fertile
seeds (perhaps by chance sorting, some seeds get the right mix of
chromosomes to be viable), and some of these have apparently added to
the number of "clones" of theÂreal germanica typeÂhybrids. There are
wild populations of these too, mostly along the north side of the
Mediterranean, but in theory they are mostly made up of relatively few
individuals that have been moved around by humans and then naturalized.
Â
Our Intermediate Bearded class ofÂcultivated bearded Iris mostly haveÂa
similar chromosome makeup, and most are produced by crossing Tall
Bearded Iris with Standard Dwarf Bearded, since the 44(+/-) chromosome
IB Iris also have reduced fertility. Some of the older cultivars are
dead ringers for I. x germanica, and cannot be distinguished based on
their structure. A few of these that were (or probably were) man-made
in relatively recent timeÂinclude 'Golden Cateract', 'Crimson
King',Â'Eleanor Roosevelt', 'Southland', and others like them. I.
albicans is often not associated with I. x germanica, but it is of this
type too, as is I.Â'Florentina', as well as all of the sports of
these two.
Â
Â
and so on.
Â
Dave Ferguson in New Mexico
Â
To: iris-species@
yahoogroups.com
From: eleanore@mts.net
Date: Fri, 28 May 2010 09:49:19 -0500
Subject: Re: [iris-species] I croatica
Â
ï
Thanks for the explanation, Bob.
Â
A few years ago, I got the US
version of I germanica from HIPS. It didn't even survive it's first
winter here. I croatica has formed a lovely clump in it's 5 yrs here.Â
I got it from Chuck, so maybe he can comment on it.
Â
While I do know my median and dwarf
iris very well, I don't know all that much about species iris. I do
love them all though.
Â
I'm here to learn. :)
Â
El, near Winnipeg, Manitoba, Canada
Z3
AIS Region 16
-----
Original Message -----
From:
r*@embarqmail.com
Sent:
Friday, May 28, 2010 9:36 AM
Subject:
Re: [iris-species] I croatica
While it is certaibly true that Iris croatica belongs to a
complex of species that have been relegated to Iris germanica, it is
not at all bad form to use the name Iris croatica. Iris germanica and
its allies have been very poorly studied. Brian along with many western
Botanist tend to be lumpers. But the splitters have separated out a
number of species. Iris germanica should be a bit of an embarassment
for any Iris taxonomist since although it is the type for the genus,
and yetÂit has been very very poorly defined and studied. What is
called germanica in the USA is a clone that is practically sterile and
triploid. It has been studied enough to believe it is a natural hybrid
but the parents have never been figured out. Iris croatica on the other
hand blooms later and is quite fertile. It is sad how much we really do
not understand. I do not think Brian or anyone else at this time would
insist on croatica as only a synonym, even if it is convenient to lump
it with germanica.
----- Original Message -----
From: "David Nicholson" <d.avensis@virgin.net>
To: iris-species@yahoogroups.com
Sent: Friday, May 28, 2010 8:03:14 AM GMT -05:00 US/Canada Eastern
Subject: Re: [iris-species] I croatica
Â
Brian Mathew has Iris croatica as a synonym of Iris germanica.
David Nicholson
in Devon, UK. Zone 9b
El Hutchison wrote
<Here's I croatica blooming today. That's one of my raised iris
nursery
beds in the background.>
