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Re: Re: *germanica*

  • Subject: Re: [iris-photos] Re: *germanica*
  • From: "David Ferguson" <manzano57@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.
 
There is a complex of 44 chromosome clones usually referred to I. x germanica (I left the x out, but probably shouldn't have).  At least they are usually all refered to I. x germanica.  Many of these were clones that were given species names; they include, but are not exclusive to atropurpurea, biliottii, alba, caerulea, Cretan, Crimson King, deflexa, florentina (as usually currently recognized, though this is likely incorrect), Fontarabie, Gypsea, Ingeborg, Istria, kashmiriana (some clones), Kharput, kochii, nepalensis, Purple King, Seattle, Sivas, Violacea, vulgaris, Zua, etc.  I didn't list all the sports of Florentina (except Zua), nor of albicans.
 
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.
 
Some more modern ones, that seem to me to represent similar ancestry (though the TB side is often a hybrid cultivar, or just given as TB in my data) might include:  Abelard, Ambera, Andalusian Blue, Autumn Gleam, Autumn Queen, Berenice, Black Hawk, Chiltern Gold, Cosette, Crysoro, Dorothea, Eleanor Roosevelt, Father Time, Gentius, Gnome, Golden Bow, Ivorine, Kurdistan, Marine Wave, Maygold, Papio, Primavera, Purple Beauty, Sangreal, Sea Foam, Soledad, Susa/Sosa, Southland, Ta-Wa, etc. I have not seen many of these though, and I suspect (?) that some are no longer with us. Some are backcrosses of a 44 clone back to one of the supposed parent species, in which case they would still be considered as I. x germanica as long as both (and only the two) parents are included. The ones in bold are apparently wild species hybrids of the right combination (if I'm right about the parents).
 
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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