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Post by Alexis on Mar 7, 2008 19:06:52 GMT
Interesting.
Genetics give you the answer, but morphology is clear to me and I do dispute the notion that burkii is vastly different from venosa and personally think that ssp. purpurea is very distinct from the other two.
I'd go for
Sarracenia purpurea ssp. purpurea Sarracenia purpurea ssp. burkii (or rosea) Sarracenia purpurea ssp. purpurea var. venosa
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Post by Dave Evans on Mar 8, 2008 1:16:40 GMT
Which purpurea are you referring to? There are more physical pitcher differences between ssp. purpurea and ssp. venosa than between ssp. venosa and var. burkii! Alexis, You have it exactly in reverse. The main reason people are under the impression of this is because nurseries continue to send out mis-labeled plants. In the past, this has even included Dangerous Plants, my nursery. We have finally resolved the problem on our end, but others have not. Most of the time; S. rosea comes in labeled as "S. purpurea venosa" and the burkei name is left off as it was considered not important. These are seedlings/and or TC starts. The only plants of S. purpurea venosa are from between Virginia south into the northeaster corner of Georgia. The plants from the panhandle were mistakenly added into S. p. v. are mis-labeled in cultivation. I hope this helps illustrate how this taxonomic problem happened. We have to refer back to naturally occurring plants, not plants that have been mis-labeled. No one has ever found S. purpurea venosa south of the northeastern corner of Georgia, in this species' entire history. There isn't a single record of it ever, except for cultivated plants. Even people who don't want purpurea to be split have never found it in Florida. And while they say they haven't seen it, they also mention the prostrate pitcher plants are too common to pay attention to. Well, if someone is not paying much attention, I am not going to put much weight into their conclusions. Have you found a naturally occurring example of S. purpurea venosa in the Florida panhandle area? I don't know what to make of the montana plants, other than they are extremely rare due to habitat destruction, and that their habitat has always been rare; much more so than the 'normal' habitats you'll find purpurea or rosea in. It could simply be an ecophine (?) of S. purpurea venosa, and it is probably already correctly named. I am sure it belongs in S. purpurea and is not directly related to S. rosea. I am basing this on morphology and also the chemicals found in the plants. Here is an image with bad data in it, still labeled wrongly, even the name of the file is incorrect:
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Post by Aidan on Mar 8, 2008 1:33:39 GMT
There's an interesting paper that came out of the Ellison lab that showed (if memory serves) that in S. purpurea, the subsp. we call venosa occupies territory that has never been glaciated, while what we call subsp. purpurea is in previously glaciated territory. And if you chart various characters against climate characters, you see a smooth gradation. The implication is that subsp. purpurea occurred as a northward invasion of subsp. venosa, and that since there are smooth correlations between taxonomic, environmental, and geographic characters, that really we're just seeing variation in a single entity, i.e. S. purpurea. If (big if) I'm interpreting the results correctly, is not the implication that plants in cultivation sourced from different locations will all end up appearing (morphologically) pretty much the same?
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Post by BarryRice on Mar 8, 2008 1:48:03 GMT
Hey Aidan,
I think you might be correct. But I think we all agree that plants in cultivation tend to be selections from plants that the collector considers "superior" in one way or another, so selection effects could muddle this up.
It might be that the authors would be more likely to say that, yes, an unbiased selection of a set of plants, in cultivation, would tend to settle down to the same general appearance in common cultivation, if given sufficient time.
But is sufficient time a few years, or a few thousand? I don't know. Furthermore, I'm off on travel to S. rosea land and won't be back for a week to ruminate more.
It is an interesting paper, though, and one I think that merits some thought.
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Post by Dave Evans on Mar 8, 2008 4:22:13 GMT
Dear Aidan,
This could be a good reason why S. purpurea venosa will sometimes look exactly like S. purpurea purpurea... and visa-versa. I have always assumed it had to do with the plants producing slightly different looking leaves throughout the growing season. The more locations I visit, the more interchangeable S. purpurea purpurea and S. purpurea venosa become to me.
BTW, venosa is critically endangered. And S. rosea will soon be as well.
Just to confuse everyone further, Rich Sivertson has told me that some old conservation workers moved plants of S. purpurea into areas that were logged to replenish the pitcher plant populations.
But what does it mean for further studies on these plants? How can we know which populations were part of these "replenishment" efforts? How far south did they go to find pitcher plants? I suspect that most of the plants that were moved came from the pine barrens in New Jersey and probably Delaware, since they are close by, but I don't know how to find out for certian...
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Post by rsivertsen on Mar 8, 2008 13:43:50 GMT
Actually, Dave, and all, according to a few college professors in a few universities (who requested anonymity on this matter), told me that several other universities were involved, some in the Virginia, North and South Carolina areas, possibly even further south. Other people, in their own private interests also played a role in transporting plants from southern sites for various reasons.
They had a working relationship with a few developers, (perhaps even the Army Corps of Engineers), who would also help the volunteers relocate some bog plants when a massive clearing or flooding would destroy the site. I've heard this accounting from a few sources.
These plants were transported into large open tracks of land in northern areas that were recently cleared due to logging, or strip mining, which became the new homes for these plants.
In some areas across Pennsylvania and other states, old sink holes that already contained some sphagnum, (and eventually became quaking bogs as the sphagnum grew from the periphery to cover the ponds and lakes; some pretty deep), were also the recipients of these relocated plants. If an existing population of S. purpurea existed in any of these areas, the gene pools would have undoubtedly been combined over the years.
I have personally visited one such site in Pennsylvania, near Stroudsburg, where I saw a large floating sphagnum bog loaded with S. purpurea that were more characteristic of the Southern varieties being more green, even in full sunlight, with larger and more undulated hoods. Also, in the same bog, were Black Spruce (Picea mariana), and Tamarak (Larix laricina) trees, (the only deciduous conifer); both are usually found much further north and in bogs.
The S. purpurea that are found throughout the NJ Pine Barrens, and northward through New York, and Massachusetts, are fairly uniform across this large region, having redder pitchers and smaller and less undulated hoods.
We are not the first generation of people who are fond of these plants, and would spread them into suitable areas, especially if these plants may be in peril in their original sites. Just like us, there have been many people, in various walks of life, all throughout time, who have had an interest in unusual plants, including CPs.
Imagine the people who worked in the various trains and road crews, or those who may have been in the turpentine and logging industry, who had access to such remote sites and bogs, with populations of CPs, orchids and ferns, knowing that one area where hundreds of acres of land that was recently cleared for turpentine, or sand/gravel, now had sphagnum and other bog plants growing, but without any CPs (Drosera, or Sarracenia, etc) and another site, loaded with CPs was about to be destroyed when a dam is completed; what would you do?
Those of us in the Frostbug, Md. CP Convention took a field trip to a lake that was once a bog, and we drove to the end of the access road, and we could look accross the lake to the other shore and see the same road leading to the edge of the lake.
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Post by ICPS-bob on Mar 8, 2008 16:58:44 GMT
Very interesting discussion with a wealth of information. Also, in the same bog, were Black Spruce (Picea mariana), and Tamarak (Larix laricina) trees, (the only deciduous conifer); ... Actually, there are 18 species of deciduous conifers: 13 species of Larix Pseudolarix amabilis Taxodium distichum Taxodium ascendens Metasequoia glyptostroboides Glyptostrobus pensilis
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Post by rsivertsen on Mar 8, 2008 17:02:45 GMT
Bob, thanks for that update, the Tamarak (Larix sp. could be a few different species) around here is the only deciduous conifir I know of, so, I stand corrected!
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Post by Aidan on Mar 8, 2008 17:25:11 GMT
But is sufficient time a few years, or a few thousand? I don't know. If observable differences are caused only by climatic conditions and availability of nutrients, the hypothesis ought to be testable over the short term. In fact, given that the samples may be biased to some degree, we would all be inadvertently testing it in our collections. If the timescale is thousands of years or more, then surely we are starting to get into the realms of speciation where morphological differences between disparate populations are (becoming?) permanent.
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Post by Dave Evans on Mar 8, 2008 20:51:57 GMT
Dear Aidan,
You're right. There probably is no need to wait more than a generation or two for this to be clarified. If you had a large enough sample, you could probably do it yourself, just to double check the results of previous studies. (Real science is thoroughly reviewed and double checked!)
One thing which can happen in the earlier stages of life, an organism can 'tune' its DNA, and other methods, to alter the express of various characteristics. This is similar to how a stem cell becomes a liver cell. Generally, once set in their ways, cells stay as they are. A liver cell will not become a bone cell, even though the DNA in them is the same. The differences we see between plants of S. purpurea venosa and S. purpurea purpurea are probably analogous to the situation with different cells in the same organism.
Simply transplanting into different soil and climate may not change the expression of all the genes. Raising a generation or two from seed in different conditions will allow for a more complete expression of the organism's genetic potential.
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Post by Alexis on Mar 9, 2008 21:43:31 GMT
Hi Dave
You've confused me somewhat. The three general 'types' (purpurea, venosa, burkii) are distinctive in cultivation regardless of tissue culture output and location data.
It all depends whether you have received your plants from a good source or not. I don't own any tissue cultured purpureas.
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Post by DelawareJim on Mar 13, 2008 17:04:29 GMT
We are not the first generation of people who are fond of these plants, and would spread them into suitable areas, especially if these plants may be in peril in their original sites. Just like us, there have been many people, in various walks of life, all throughout time, who have had an interest in unusual plants, including CPs. Imagine the people who worked in the various trains and road crews, or those who may have been in the turpentine and logging industry, who had access to such remote sites and bogs, with populations of CPs, orchids and ferns, knowing that one area where hundreds of acres of land that was recently cleared for turpentine, or sand/gravel, now had sphagnum and other bog plants growing, but without any CPs (Drosera, or Sarracenia, etc) and another site, loaded with CPs was about to be destroyed when a dam is completed; what would you do? Those of us in the Frostbug, Md. CP Convention took a field trip to a lake that was once a bog, and we drove to the end of the access road, and we could look accross the lake to the other shore and see the same road leading to the edge of the lake. Interesting that you mentioned this. Last summer, I visited the Suitland bog, a coastal plain bog in Prince Georges County, Maryland. I was given a guided tour by the park ranger who stated the S. purpurea in the bog were planted at some point. They also found a few VFT's on deaths door, and now question the nativity of the Drosera intermedia and D. filiformis. What was interesting was although we were told the pitchers were ssp. purpurea, they exhibited morphological characteristics of almost the entire purpurea range. Unforunately, the rangers' parting comment as we were leaving that since the pitchers were introduced and they were starting to overrun the bog, they planned a major weeding out at some point in the near future.
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Post by Dave Evans on Mar 18, 2008 0:27:57 GMT
Ah, finally got to edit and rename this photo over the weekend: Checkout the red venation! The pattern is very similar to the seen on plants of S. flava rubricorpora. The only traits S. purpurea venosa and S. rosea share is the more exaggerated hood with more frills, and the pitcher shape can be more squat in venosa, but this is not consistently displayed by all plants in a population, hairiness is also very variable in S. purpurea venosa. There are more than a dozen features that S. purpurea purpurea and S. purpurea venosa do share, which they don't share with S. rosea. It could be that (like has been mentioned for the New Jersey plants...); perhaps S. purpurea venosa is part of an area where S. rosea and S. purpurea used to overlap, an ice ago or two ago... And the in between plants (venosa) favor S. purpurea for some reason...
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Post by Alexis on Mar 18, 2008 18:40:32 GMT
Some great photos of wild purpureas (amongst others) showing their wide range: www.bestcarnivorousplants.org/fotogalerie/sr134-.htmlI think we have in our minds what each species is generally like, but it's not until you see what's actually out there that you realise how little you actually know! I remember some of Barry's oreophila photos looking nothing like your typical oreo, or any other sarracenia for that matter.
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john
Full Member
Posts: 30
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Post by john on Mar 18, 2008 23:24:06 GMT
Thanks bob, for the link to the paper by Ellison et al. Certainly gave me plenty to think about (and I wrote two pages of notes - lets not go there just yet). Ellison et al. conclude that the morphological differences between S.p.purpurea and S.p.venosa are climatic and environmental, and as Aidan points out, the obvious conclusion is that the plants will become indistinguishable in cultivation under the same conditions. This has not been my experience, has it been for anybody? I note your comments, Dave, on cell differentiation, but I think it is probably as well to point out that plant cells do not differentiate to anything like the degree that animal cells do, and the process in plant cells is reversible (more or less). Plant cells are effectively totipotent (any cell can potentially regenerate the entire plant) - tissue culture is one of the jolly consequences. Under the same conditions, the individual plants should adapt to resemble eachother, it should not require any additional generations. Has anybody got the original diagnoses of S.p.purpurea and S.p.venosa available? I can't lay my hands on them at the moment. Are lip width, mouth width and width:length ratio actually the key diagnostic features of the subspecies? One point worth mentioning is that the paper demonstrates a statistically significant difference between the southern (Florida) taxon and the northern. It would be rather early to draw any taxonomic conclusions from this data. The paper's own conclusion is that pitcher morphology variation can be accounted for by environmental and climatic differences. Hidden within the water chemistry data are some interesting comments. They took pore water samples from 27 northern populations. They were only comparing these with a much smaller 12 southern populations, but they were only able to get pore water samples from 4 of those, because the soil was too dry. Water availability would seem a major environmental factor to me. Environmental factors influence pitcher morphology (the paper's own conclusion). Any inference that there is a taxonomically significant statistical difference between the populations remains rather speculative.
Sorry - too many words to make a simple point.
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