Re: Re: *germanica*
- Subject: Re: [iris-photos] Re: *germanica*
- From: &* F* <m*@msn.com>
- Date: Sun, 14 Mar 2004 16:40:59 -0700
- Seal-send-time: Sun, 14 Mar 2004 16:41:00 -0700
You'll have to excuse me for thinking like a botanist more than as a
horticulturalist. It often gives a somewhat different perspective.
My tendency is to think of plants always in the context of how the relate to
their wild populations (or ancestors). I do not tend to see individual
clones of plants (such as cultivars) as quite the autonomous entities as others
often do. To me they are still part of a greater whole.
You can tell I like this subject. Others know more about it,
but this is something of my take on it. It seems from what I've been seeing in the literature that I. x germanica
is actually a varied complex of similar hybrid clones, and also that it is
naturalized quite widely around the Mediterranean Basin.
Admittedly I. x albicans is rarely included under I. x germanica, but it
has the same chromosome compliment, the same reduced fertility, basically the
same morphology and behavior, and it is almost certainly derived from
similar hybridization. The real question would be "does it have the same
parents"?
Just as an example of how it would work, let's make some assumptions for
the sake or argument. First lets say that I. x germanica (the original
plant) is indeed I. lutescens x a wild TB. Now lets say that all Near East
TB's are really the same species and call them I. trojana. So we get I. x
germanica = (I. lutescens x I. trojana). I know this may not be true, but
let's go with it. That means that all plants with just these two species
in their ancestry would be called I. x germanica. It doesn’t matter if
they are 4000 years old, or if they were made yesterday. Also, it doesn't
matter how many generations were involved. As long as just those two
species were involved. If they should become self perpetuating wild
species, we would eventually drop the x and just call them I. germanica
(something like the situation with I. lutescens), but that is something else for
a new debate.
If the parentage is the same for all these, then they are indeed all
properly referred to I. x germanica (which is the oldest legally published
name for them). These other names become synonyms or can be used to
recognize individual clones as cultivars (which is how they are used
functionally anyway).
Sass was using Near Eastern tetraploid species crossed with "Chamaeirises"
to create his IB line, and the clones I've seen from that breeding really look
the same as I. x germanica, except more varied in color. This adds to my
feeling that this is the basic parentage of I. x germanica. If he did
indeed use the same parentage, then these (and a number of other) IB
clones might indeed be botanically referable to I. x germanica.
I agree that I. chamaeiris (part of what is being lumped into I. lutescens
now) is probably one of the parents. However, it seems that there is
little agreement on the parentage of I. x germanica. However, nobody seems
to have settled just what the parentage was. There seems to be lots of
supposition, but little hard fact. The fact that each tetraploid clone in
cultivation from the Near East (and similar plants found elsewhere) has a
different species name does not help the situation, and it seems to me that
somebody should do some field work and determine the limits of the real wild
populations of these tetraploids (wish I could!). Some of these
tetraploids were clearly grown and spread around a long time ago. The
theory I favor is just one, and it is not necessarily correct. It just
seems to me that because I. x germanica is only common as a "wild" plant
around the Mediterranean, especially in France, I. lutescens (and synonyms,
variants, or relatives) is a prime suspect. This is the perfect choice for
the small parent, as the chromosome numbers are correct, and the morphology
makes sense. To me I. pallida and I. variegata make little sense as
parents, while again the TB tetraploids fit the bill nicely. I. aphylla
has a similar look, but my impression is that it is from the wrong part of the
world to be likely, was not grown much if any by Mediterranean peoples, and
besides it makes little sense as the "other" parent, since it is too small and
morphologically and phenologically off the mark for a suspected parent.
Since mismatched chromosome sets (such as 44 which is clearly
[8+12]+[12+12] in this case) generally produce low or no fertility, it seems
unlikely that multiple crosses with multiple generations and multiple species
would be involved, and it seems much more likely that each "wild" clone is an F1
hybrid. Backcrosses of these F1's would also be very unlikely to produce
more plants with the same chromosome number, and crosses between them would
likely also be of different chromosome numbers. Unreduced gametes from I.
pallida or I. variegata crossed with I. lutescens would give the correct
numbers, but I seriously doubt the morphology would match I. x germanica.
If it is one of these, I would definitely favor I. pallida, as it grows in the
correct region, and it is tall enough; however, it just doesn't seem like it
would fit the bill in other areas.
As for the 40 chromosome wild species (I. lutescens and kin), they are
indeed probably amphidiploid hybrid in origin, but are wild reproducing species
now, and they can be considered as full species in their (its?) own
right.
It is a great area for somebody to do some genetic analyses and to do some
hybridization experiments with wild species to see what I. x germanica really
is. I'd love to learn more of any molecular work that might be going on in
this area.
There is a tendency in the horticultural world (especially noticeable with
Iris) to consider each individual clone as something unique, and this is fine in
horticulture for cultivars (certainly not meant as a criticism, just a different
perspective), but that tendency has been applied in the the past to a lot of
wild plants, when individual clones were named as full species. There was
no understanding of the wild populations. It seems that in many
cases, especially in the Near East, the information on just
what occurs in the wild species populations is still very unclear (for
example the tetraploid TB species).
By the way, in the previous message, when I said "undulata", I think I
meant "reflexa".
Best to all,
Dave
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