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Post by meadowview on Oct 15, 2007 13:23:54 GMT
Hi Manny:
Sarracenia leucophylla did not get anywhere near the Okefenokee Swamp in GA. If someone found it there then it was planted. Sarracenia leucophylla is a Gulf Coast plant and made a stab up into SW Georgia (with a possible disjunct population near Atlanta at Fairburn) reaching its northern limit near Americus, GA. The historical populations near Americus have all been wiped out (they also had S. rubra and one site even had one S. leucophylla x S. flava, but no S. flava, and that was in the early 1900's and shows the extent of loss even at that time).
I spent a lot of time trying to rediscover S. leucophylla in SW GA and the one site I couldn't access ended up having the last population in GA. This population is in SW GA and ABG has been working with the plants (by the way, ABG has done a great job for pitcher plant protection and restoration in GA).
Best,
Phil
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Post by Aidan on Oct 15, 2007 13:38:58 GMT
Schnell has contributed much to our knowledge of Sarracenia. However, I believe he really missed the mark on Sarracenia alabamensis. My problem with his handling of S. alabamensis is that he de-elevated S. alabamensis to a subspecies of S. rubra in "Carnivorous Plants of the United States and Canada", having not observed the plants in the wild before he did this. Yet, in the same section of the book, he harks about people elevating other subspecies of S. rubra to species status with only "irregular field visits." Also, in this same section of his book, he called the Case's work "not thorough," without mentioning what was not thorough about it. This appeared to be a rather cheap shot, whether or not it was intentional. Heated emotions could have been kept at bay if he had stated what about the work was not thorough enough. For a few years after this, it appeared that Schnell was simply on a mission to prove that S. alabamensis was a subspecies of S. rubra. While some of his points on similarities were valid, he appeared to only hark on these, and really didnt mention or simply dismissed the glaring differences. You can't have it both ways... If as has been forcibly expressed here you choose to accept the quoted molecular study as solid proof that "S. rosea" is a separate species, then you also have to accept that "S. alabamensis" is not.
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Post by Michael Catalani on Oct 15, 2007 15:01:58 GMT
Schnell has contributed much to our knowledge of Sarracenia. However, I believe he really missed the mark on Sarracenia alabamensis. My problem with his handling of S. alabamensis is that he de-elevated S. alabamensis to a subspecies of S. rubra in "Carnivorous Plants of the United States and Canada", having not observed the plants in the wild before he did this. Yet, in the same section of the book, he harks about people elevating other subspecies of S. rubra to species status with only "irregular field visits." Also, in this same section of his book, he called the Case's work "not thorough," without mentioning what was not thorough about it. This appeared to be a rather cheap shot, whether or not it was intentional. Heated emotions could have been kept at bay if he had stated what about the work was not thorough enough. For a few years after this, it appeared that Schnell was simply on a mission to prove that S. alabamensis was a subspecies of S. rubra. While some of his points on similarities were valid, he appeared to only hark on these, and really didnt mention or simply dismissed the glaring differences. You can't have it both ways... If as has been forcibly expressed here you choose to accept the quoted molecular study as solid proof that "S. rosea" is a separate species, then you also have to accept that "S. alabamensis" is not. Haha...well, I dont think I've gone both ways. I havent utilized molecular studies for any of my basis for species elevations. And I have no problem with Schnell lumping versus me splitting S. alabamensis. The problem I had was him de-elevating a species without doing the proper research in order to determine if it was the correct thing to do. His de-elevating S. alabamensis at that point in time was simply conjecture. Whether or not people or lumpers or splitters really doesnt bother me at all. BUT Consistency should be the name of the game. If you believe S. alabamensis is a subspecies of rubra, then S. oreophila should also be a subspecies of S. flava.
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Post by Aidan on Oct 15, 2007 16:25:26 GMT
All of which rather makes the point that the results of these studies should be taken with a hefty dose of salt and treated with considerable caution. Having discussed the subject with a botanist in the dim and distant past, my limited understanding is that these molecular studies prove little if anything owing to the narrow range of genes studied. Pick another group to examine and the conclusions may be entirely different.
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Post by meadowview on Oct 15, 2007 16:53:07 GMT
Hi Folks:
Regarding the species status of S. rosea vs. S. purpurea here are some additional things to consider. While S. rosea and S. purpurea appear superficially similar there are numerous characteristics which are different and have been enumerated on this forum (flower color, scape height, pitcher morphology, geographic distribution, isozyme differences, ecological niche, ec.,).
While natural selection and evolution have produced recognizable differences that we can see I think that there are important differences that are not so easy to see (isozymes differences) that reflect a broad divergence and speciation event between S. rosea and S. purpurea. In essence, the basic form of S. purpurea is a good design but the evolution of S. rosea has taken place in other areas where natural selection has been strongest for the gulf coast region (e.g. flower color, scape height, a host of enzyme functions like cold hardiness, leaf waxiness or deciduousness in cold, etc.). In many ways S. rosea could almost be considered a cryptic species because selection has taken place at a level that is not always obvious at a morphological level.
While I'm not dogmatic in my taxonomic lexicon, and certainly think people can have their own opinion in botanical matters based on data they think is relevant to the matter, I think S. rosea is a good species and worthy of recognition.
Sincerely,
Phil Sheridan Meadowview
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Post by John Brittnacher on Oct 15, 2007 19:20:05 GMT
All of which rather makes the point that the results of these studies should be taken with a hefty dose of salt and treated with considerable caution. Having discussed the subject with a botanist in the dim and distant past, my limited understanding is that these molecular studies prove little if anything owing to the narrow range of genes studied. Pick another group to examine and the conclusions may be entirely different. With the molecular studies to determine species relationships there is only one side of this coin. If you find differences, no matter how few or many genes you study, there is a difference. Yes the more the better, but one is sufficient. If you don't find any differences, you have not gotten anywhere. The next gene you study could be THE one that is diagnostic. So the only conclusions you can make are what things are different. You can not use molecular studies to determine things are the same (unless you use techniques that asses a huge number of genes or you have prior knowledge from other studies and you are essentially fingerprinting individuals). Now where these things get into trouble is if you only study one individual of each species. To get a proper analysis you should assess at least 10 independent copies of each gene for each species assuming nuclear genes and diploid chromosomes. I don't know how studies using extrachomosomal genes or polyploid species affect that number. The reason for the 10 copies is that is usually what it takes to be assured you find the most common variants in the population. Another issue is whether "molecular species" are valid in taxonomy. I don't think we want to get into that as the arguments get heated. So in the case of S. rosea we are using the molecular evidence as supporting what we already know from the physical characteristics.
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Post by Alexis on Oct 15, 2007 19:27:13 GMT
I still can't see how the pitcher morphology is different enough to use as evidence for a whole new species. Ssp. purpurea, ssp. venosa and burkii/rosea all have different pitcher characteristics, but not one of them is 'more' different from the other two.
As for flower colour, yes they're either pink or magenta. But am I the only one that finds that ssp. purpurea has darker petals on average compared with ssp. venosa, which are often a brighter red. Are we lumping dark red and bright red together because they look similar? Is pink further away from red than maroon is to red? If they were yellow, fair enough, but they are actually just another notch up on the red colour chart. A period of time growing in the same region as other yellow flowered sarracenia shouldn't mean it's such a surprise that the southern species does have lighter petals. Is a coincidence that the further south you go, the overall trend with purpurea is for the flowers to become more suffused with lighter shades? With regards to flower scape height, I suppose the crucial question is whether it's significant. It's obviously a consistent feature, but whether it's significant is open to individual opinion. Are the petal size and shape differences between venosa and purpurea 'more' significant than the height of burkii/rosea flowers because th height difference 'looks' more significant visually? By that argument, s. minor should be split into 2 species surely?
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toof
Full Member
Posts: 4
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Post by toof on Oct 16, 2007 0:06:08 GMT
Hi Dave,
The relation between flava and oreophila is easy to see in form and flower. I've always considered oreophila to be the ancestral form due to it's upland habitat. As commonly seen thoughout nature, the upland form of a plant with a lowland counterpart is usually the ancestral form. Perhaps, as you mention, oreophila has hybrid influence. It's habitat and geography is quite close to alabamensis. That could certainly explain it's nDNA relation with rubra. Addtionally, the literature suggests that it's easy to mistake alabamensis for oreophila from a moving train. All the best, Stefan
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Post by Dave Evans on Oct 16, 2007 4:59:25 GMT
Hello Stefan,
Hmm... Well the odd thing about S. rubra alabamensis is it makes those S. oreo pitchers in the fall, while S. oreophila makes them in the spring... I do suppose that the genes responsible for producing these leaves could be the same in both species, or more accurately derived from their common ancestor and are still very similar. However, what simulates those genes for expression has become different or switched around...
I used to think of S. oreophila as ancestral to S. flava, but now I think it is just conjecture. I do think they are each other's closest relative. I just cannot tell which is the older of the two. For example, is S. o. an old species that is dieing out, or is it a new species that is just getting going, but is now suffering massive and unnatural habitat loss?
I would say that if S. flava and S. oreophila have a relationship in which one is directly derived from the other, they could be considered as subspecies of the same species. Given the additional input from S. rubra placing it somewhere between both S. flava and S. rubra it is very difficult for me to consider them subspecies of the same species; because it is clear to me that since the time when S. rubra and S. flava mixed to form S. oreophila it has established itself and has evolved in a ecological direction different from both likely parent species, even though overall it appears to favor S. flava morphologically and with regards to the way they both make spring and summer pitchers versus late summer and fall phyllodia; its spring pitchers actually favor S. alabamensis fall pitcher more than they do those of S. flava. Forget about viewing them from a train, they look the same when viewed in person.
Anyone observe double flowers on S. oreophila? This trait is supposed to be exclusive to S. rubra.
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Post by Dave Evans on Oct 16, 2007 5:54:05 GMT
I hear what you are saying about the flower color. However, I have not noticed the details you're mentioning about the three named S. purpurea groups. Are you saying the flowers of S. purpurea venosa are lighter in color than those of S. purpurea purpurea or that S. purpurea venosa goes from darker to lighter the further south in the range you go? The first paragraph below is only true when read from Dr. Schnell's book, when you go out into the field and review dozens of plants in many locations things do not appear any where near as simple as Dr. Schnell suggests. I recently visited a location for S. purpurea with Rich in New York state, close to the Jersey border and the plants growing there appear to be the same taxonomic entity found in Pine Barrens of New Jersey and somewhat different from those around the Great Lakes which have longer leaves and a different shape to the opening of the mouth. These plants from New York are much more similar to the plants from North Carolina than the plants from North Carolina are to those found in Florida. Oddly, the 'purps' from Florida are the least cold hardy species in Sarracenia--the entire genus. How is it even possible the other species that grow along side S. rosea are more cold hardy than it is? Could it be they migrated from the north while S. rosea has been in the south for far longer? I have not been able to compare flowers from the Great Lakes plants to those of other groups yet... However, I have seen them and nothing stuck me as particularly different. Similar odor also. I still can't see how the pitcher morphology is different enough to use as evidence for a whole new species. Ssp. purpurea, ssp. venosa and burkii/rosea all have different pitcher characteristics, but not one of them is 'more' different from the other two. As for flower colour, yes they're either pink or magenta. But am I the only one that finds that ssp. purpurea has darker petals on average compared with ssp. venosa, which are often a brighter red. Are we lumping dark red and bright red together because they look similar? Is pink further away from red than maroon is to red? If they were yellow, fair enough, but they are actually just another notch up on the red colour chart. A period of time growing in the same region as other yellow flowered sarracenia shouldn't mean it's such a surprise that the southern species does have lighter petals. Is a coincidence that the further south you go, the overall trend with purpurea is for the flowers to become more suffused with lighter shades?
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Post by Alexis on Oct 16, 2007 22:59:29 GMT
Hi Dave My point really was to highlight the difference between the flowers of ssp. purpurea and ssp. venosa. The consensus is that they are broadly similar, but they are actually some differences with regards to petal colour and shape, and the size of the blooms. I was just trying to highlight these differences, as opposed to the 'rosea flowers are short and pink and the rest are tall and red' overview.
With the north-south subject, I meant that, in general, ssp. purpurea has the darkest flowers (especially when you look at the sepals), ssp. venosa is a lighter, brighter red and rosea/burkii is pink/magenta. Obviously there will be a mish-mash with the purpurea/venosa overlap areas, but the overall trend is for the flowers to get lighter (and larger) further south you go when you look at the locations of the three 'forms'.
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Post by Dave Evans on Oct 17, 2007 17:00:30 GMT
Dear Alexis, Where are you get this information about the flowers from? I am sort of confused. I have done a lot of traveling looking at S. purpurea (broad sense) and have not noticed this pattern. Of course my observations are only a tiny part in the whole picture. The lack of shared traits between S. purpurea venosa and S. purpurea venosa burkii is one of the main things I noticed when I first when down into Florida after making several trips into Carolina. (I also noticed that some of the plants referred to as D. capillaris in the gulf coast are probably a different species, I suspect it is the result of hybridization like D. anglica.) I didn't even know about S. rosea for several years, but was already convinced it was an unrecognized subspecies. This was re-enforced by watching plants growing from seed of all three group and I was surprised that even the seedlings of S. rosea look different from those of the other two "purps" while the two northern varieties are more similar. You can observe a similar level of difference in the seedlings of various Heliamphora species. Little did I know that it was recognized and named. At a CP-meeting at Meadowview, I mentioned that I am extremely confused about how the plants in the Panhandle area are also named as S. purpurea venosa I said, 'they are easily a separate subspecies, and if they are a subspecies the other two subspecies are actually one.' And then Phil Sheridan explained that Fred and Roberta Case and Robert Naczi did name it as a species. I wasn't all that happy with the name, but it is a reference to the flower color and that is the first major difference that can be observed (even from a car or train so I suppose the name really does match the species... BTW Aidan, the genetic study should not be taken as "proof" they are a separate species. But it does demonstrate the species we see now in Sarracenia are the result of a process not covered by the overly simplistic text book version of evolution. Shoot, most the folks that have done research into Sarracenia were taught in school that hybrids are very rare, are genetic dead ends, and do not contribute to the genus as a whole. We now know this is almost completely false with regards to both Nepenthes and Sarracenia. I think the ice-ages have had an enormous impact on Sarracenia as a whole and on many lowland species of Nepenthes, especially on the distributions of species, and perhaps even driving or forcing their evolution to various degrees.
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Post by Alexis on Oct 17, 2007 22:10:27 GMT
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Post by Aidan on Oct 17, 2007 22:31:10 GMT
Shoot, most the folks that have done research into Sarracenia were taught in school that hybrids are very rare, are genetic dead ends, and do not contribute to the genus as a whole. We now know this is almost completely false with regards to both Nepenthes and Sarracenia. I think the ice-ages have had an enormous impact on Sarracenia as a whole and on many lowland species of Nepenthes, especially on the distributions of species, and perhaps even driving or forcing their evolution to various degrees. Interspecific hybrids are comparatively rare in nature and fertile interspecific hybrids even more so. In Sarracenia and Nepenthes it most likely indicates that in evolutionary terms, speciation is recent.
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Post by Dave Evans on Oct 17, 2007 23:17:04 GMT
Dear Alexis,
I see what is going on here. The first link worked, but the second didn't, and I could not get it to work by editing either. So I ran the same search you did. Most of the images pulled up by searching for "ssp. venosa" give result showing photos of S. rosea! So yeah, those flower should look rather different from S. purpurea (strict sense), the photos are mis-id'ed or the name "burkii" has been left off the ID.
We need to compare S. purpurea venosa flowers to those of S. purpurea purpurea, not S. purpurea venosa burkii to S. purpurea purpurea, but this method of researching is giving dubious results.
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