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Thread: D. foliosa

  1. #1

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    As some of you may be aware a friend and I have been looking into the situation of upright Drosera growing in Victoria (Australia). After a lot of field work we have finaly realised that the "new species" we discoverd simply turned out to be D. peltata, but the plant we (and everyone else it seems) had always taken for granted as D. peltata is actualy D. foliosa.

    D. foliosa is a species that was discarded some time ago but seems to be alive and kicking as a distinct species from D. peltata. If only we had red some old descriptions we would have saved a lot of late nights!!

    As I said D. foliosa is NOT a form of D. peltata, if it is you have to completely redescribe what constitutes a species as both these plants coexist, look different and do not hybridise. It looks like they did know what they were on about all those years ago.

    One more plant to add to your collections

    George




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    George,

    Now all you have to do is get Dr. Schlauer to agree with you! I encourage you to write a good description stating your case for considering this as a valid species and publish it in one of the various society journals, and then call Jan's attention to it. Perhaps he will reconsider his opinion based on your field observations, and even if not there will be a record of your opinion for others to consider in the future. My hats off to you mate for the valuable field work you and others are doing in Australia. This sort of work is invaluable. Australia's isolation still makes it a perfect testing ground for Darwin's theories of speciation, and observation and recording of variation within the CP populations is a great gift to posterity, but only if it is published!
    "Grow More, Share More"

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    Moderator Joseph Clemens's Avatar
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    Of course if you're more inclined to the "horticulture" aspect of CP rather than the "scientific" you might see that the potential for registering this "different" Drosera peltata as a cultivar (Cultivated Variety) is quite a valid option versus the need to have the taxonomists agree that the differences noted by you in the field require the publication (recognition -- reaffirmation) of these plants as a distinct species, subspecies, or variety. [img]http://www.**********.com/iB_html312/non-cgi/emoticons/biggrin.gif[/img]

    CP Database link showing historical use of foliosa name

    Just a thought. [img]http://www.**********.com/iB_html312/non-cgi/emoticons/rock.gif[/img]
    Joseph Clemens
    Tucson, Arizona, U S A

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    Although I agree that cultivar publication remains an option, I still feel that recording of the variation of Australian Drosera is very important. This is one case that should involve some detailed taxonomy, firld study, and herbarium placement.

    To be honest, I have no doubt the publication will be rejected, but the effort should still be made. Very few species novae are accepted these days, and in light of the past studies and research there is little hope that this will be either. I am looking for the Conn article for you George. It will help you to know what to concentrate on.

    You should probably do some measurement of the seed. If you can get a good sample of say 1000 seeds spread over a predetermined and measured distribution, measure and record the results, I believe I could run a statistical analysis to determine if the results are significant. The more seeds the better, and you will need a microscope with a measuring slide calibrated to be able to measure a difference of about 0.1 ml..... Some seeds would be 0.2 ml and some 0.3 (this is just an illustration) You record which are which: most will fall into an obvious range those that don't are likely defectives. Compare the seed testa as well, and note the differences if they are evident. Well, this is how I would attack it anyways.

    You have to work with a stable characteristic: floral color and lamina are likely to be plastic characteristics incapable of yielding solid data: seed is much more reliable.

    I really need to find that article for you, I know I have it hard copied......somewhere!
    "Grow More, Share More"

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    Hi all and thanks for the input.

    I noticed on the CP data base that foliosa is not a valid name for this plant as it was used prior. But I still feel this plant warants species status, it just dosn't have a name any more :/... a rose by any other name...

    I feel to simply give this plant a cultivar name would be a major injustice as it is widely distributed, and uniform throughout its range (that I have sampled). And I like to see things done properly so it is worth trying to get it formaly asessed to see what it really is.

    As for seed, from what I can tell it is simmilar to peltata, which is why I feel it has been lumped into the same species. I am aware that flower colour and leaf shape can vary so did not use these as a basis for trying to identify consistent differences. What I looked at is the stigma, style and ovary structure. This was amazingly consistent over the range for each "species" and was different between the "species".

    When trying to deduce wether they were variants of the same species, I could find evidence to say they were different species, so I set the hypothoses that they were the different species and tried to find any evidence to disprove this hypothosis. I could not find any evidence against this hypothosis other than seed shape, so is probably the most correct answer. To give you an idea there seems to be more variation bettween peltata and "foliosa" than many of the Saracenia species, so giving it a cultivar name would seem to me like reducing S. psitacina to S. purpurea var. psitacina, not to mention that you can hybridise these two Sarra. species, when I have not seen ANY evidence of the Drosera hybridising. In my opinion this level taxonomy would not be very satisfactory.

    Tamlin, I am trying to collect seed at the moment, but with seed I find it can vary from plant to plant, so am dubious to how much information this can yeald. I do think it would be a very interesting study however, and will have to give it a go. I would love to see the article if you manage to find it!!

    I was going to go to the herbarium today, but work got in the way (as it does)...

    Keep the feedback comming, if anyone can see flaws in my reasoning please say so as this is why I have posted here! Right now I need as many ideas as I can get.

    Sorry if this is a bit garbled but I am dead tired (it's 1am here...)
    George

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