I've been here less than a week, and certainly learned lots already.
El
----- Original Message -----
From: "johnhb67114" <j*@cox.net>
To: <i*@yahoogroups.com>
Sent: Saturday, May 29, 2010 12:35 PM
Subject: [iris-species] Re: I croatica
Dang Dave; you're an encyclopedia. You have just added greatly
to the iris research I have been doing for 10 years now. Of
coarse I have concentrated more on the Arils and some of the
other rarer species and not so much on hybrids.
John B
--- In i*@yahoogroups.com, David Ferguson <manzano57@...> wrote:
>
>
> To expand on Bob's explanation a bit.
>
>
>
> The majority of wild bearded Iris species in Europe and western Asia (not
> including the Aril and Regalia groups) have a base chromosome number of 12
> (the number of one set of chromosomes). Most of these are diploid
> (meaning they have a single pair of sets with 24 total). This is the
> lowest number possible for most of this group. 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 triploids produced 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.
>
>
>
> The tetraploids mostly tend to resembe one another and also I. x
> germanica, and most have been lumped by some under that name. However,
> really there are several distinct looking populatoins within this group,
> and each probably represents a good "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.
>
>
>
> 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').
>
>
>
> There is also a group of wild bearded 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 cultivated MDB and many SDB Iris have 32
> chromosomes and are this ancestry.
>
>
>
> Now then, I. x germanica (what is supposed to be the "true" germanica) has
> 44 chromosomes (give or take one or two). This seems to be [12 + 12 + 12
> + 8), and is derived from crossing a 48 chromosome parent with 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 combined two sets of 8 with two sets of 12 to get a two
> new (functioning as) haploid sets of 20, yet there are still 4 sets
> present). There are a few wild reproducing populations of Iris with 40
> chromosomes, such as I. marsica, that are of this same make-up.
> Apparently one of these hybrid "40's" back-crossed with a species with 48
> chrosomes (it seems to have happened several times to give us ancient
> 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 comparing DNA. Anyway, the resulting "44's"
> seem to be vigorous plants that have been divided and spread around by
> humans for centuries, particularly in the Mediterranean region, and seem
> 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 chromosomes don'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 the real
> germanica type hybrids. 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.
>
>
>
> Our Intermediate Bearded class of cultivated bearded Iris mostly have a
> 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
> time include 'Golden Cateract', 'Crimson King', '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. 'Florentina', as
> well as all of the sports of these two.
>
>
>
>
>
> and so on.
>
>
>
> Dave Ferguson in New Mexico
>
>
>
> To: i*@yahoogroups.com
> From: eleanore@...
> Date: Fri, 28 May 2010 09:49:19 -0500
> Subject: Re: [iris-species] I croatica
>
>
>
>
>
> 
> Thanks for the explanation, Bob.
>
> 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. I got it from Chuck, so maybe he can comment on it.
>
> 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.
>
> I'm here to learn. :)
>
> El, near Winnipeg, Manitoba, Canada Z3
> AIS Region 16
>
>
> ----- Original Message -----
> From: Robert Pries
> To: i*@yahoogroups.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 yet it 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@...>
> To: i*@yahoogroups.com
> Sent: Friday, May 28, 2010 8:03:14 AM GMT -05:00 US/Canada Eastern
> Subject: Re: [iris-species] I croatica
>
>
>
> 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.>
>
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