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Post by Dave Evans on Apr 13, 2007 0:46:38 GMT
I'll be updating this message, but for for now, I am creating this thread to highlight the differences between two species of Sarracenia, S. purpurea (the purple pitchers plant) and S. rosea (Louis Burke's pitcher plant). From what I can tell, most of the confusion about these two species has been caused by their historical treatments. There are many publications which refer to the range of S. purpurea venosa as extending south along the coast of Georgia, down into the Florida panhandle and west into Alabama, Louisiana and Mississippi. However, none of these statements regarding the shape of this range have been backed up by evidence. The situation in Georgia doesn't seem to represent an extension of the range of S. purpurea venosa south, but instead the southern limit of its range. Areas south and west of the north eastern corner of Georgia yield no purple pitcher plants; and there are no historical records of them ever having occurred south or west of there. This means we should not assume there is a direct connection between the ranges of S. purpurea and S. rosea, as it has been portrayed in many publications. They are separated by close to 200 miles and there is no evidence the situation now is any different from 10,000 years ago. There actually seems to be three subspecies of S. purpurea, the one called S. purpurea venosa range is from north eastern Georgia up into Virginia, perhaps as far north as New Jersey or even Long Island. This is where S. purpurea purpurea range starts, but this subspecies is confusing, there seem to different plants along the shore, different plants in the mountains, and even an other kind around the Great Lakes. One subspecies found along the coast from Delaware up through Massachusetts. The other is more inland and is found in the mountains and west into the Great Lakes region. All the of populations which also have form S. p. p. heterophylla are part of this third, unnamed subspecies (or currently lumped into subsp. purpurea). This is the same kind of purple pitcher plant which have the vein-less and bronze forms which have been recently discovered by Jay Lechtman and Carl Mazur. The three main kinds of purple pitcher plant are all very close to each other, resembling each other at different times of the year. The flowers on all three types are very similar in their coloration, shape and odor. However, S. purpurea venosa burkii or S. rosea maintains a different appearance all year long. The flowers are different from the other purp groups, indicating the plants from the Gulf Coast area have been on a separate evolutionary path for quite a while, longer than the northern subspecies, which are all closer to each other even though the combined ranges of S. purpurea purpurea and venosa are much larger than the range of S. rosea. Bye for now, Dave E. www.dangerousplants.com
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Post by Aidan on Apr 13, 2007 1:00:14 GMT
I'm probably not alone in saying that I will take a lot of convincing that S. purpurea ssp. venosa var. burkii deserves elevation to species status. A separate race or subspecies perhaps.
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Clint
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Post by Clint on Apr 13, 2007 1:46:06 GMT
Yeah... So it has a short scape and a fat peristome. Whoop-di-do I say.
And I'm usually a splitter. I've read and read and the arguments aren't good enough for me. I'll call it S. rosea for simplicity though. Typing S. purpurea ssp. venosa var. burkii is enough to give me Carpal Tunnel.
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Post by Dave Evans on Apr 13, 2007 4:05:08 GMT
Dear Aidan, Well, I think it is kind of easy to notice, just look at the plants. I have tried going the other way, explain to myself why they should be put together, but I can't come up with any good reason to combine them... And S. purpurea, has anyone really identified where S. purpurea purpurea ends and S. purpurea venosa starts? What I see out in the field looks different from what I read in books on Sarracenia... I tend to be a lumper, but "species" means there is some "special" characteristic or interaction with the environment which is not repeated by other close relatives. It seems like we would be making an exception by keeping S. rosea combined within S. purpurea, especially the way S. p. is currently defined/structured. Good Growing, Dave Evans Ok here is Sarracenia rosea: i60.photobucket.com/albums/h15/BogBaron/State%20Park%20Day/DSC_4147_00.jpg[/img]Here is S. purpurea: .... [/img]. I'm probably not alone in saying that I will take a lot of convincing that S. purpurea ssp. venosa var. burkii deserves elevation to species status. A separate race or subspecies perhaps.
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Post by BarryRice on Apr 13, 2007 17:28:30 GMT
I think that it is interesting that molecular studies are starting to say that S. purpurea subsp. purpurea and S. purpurea subsp. venosa s. str. are more closely related to each other than either is related to S. purpurea subsp. venosa var. burkii.
From this accumulating evidence, it would be incorrect, I think, to continue to think of the latter entity as a variety of S. purpurea subsp. venosa. It might be appropriate to treat it as a somewhat more distantly related subspecies, but not a variety of venosa. Unfortunately, there is no S. purpurea subsp. burkii or S. purpurea subsp. rosea name available for use.
I'm probably middle of the road, neither lumper nor splitter. But I do think the S. rosea name has merit, and I've adopted it.
Barry
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Post by gardenofeden on May 8, 2007 11:54:44 GMT
I have to say that I do not agree with the Sarracenia rosea name, and I'm still not sure exactly what is supposed to make this purpurea different to all the others...?
Flower colour: no, flower colour is not a reliable character to separate species as it can be down to one or two genes... look at the existence of yellow flowered variants of leucophylla for example... now flower STRUCTURE, that would-be important, which is why Linnaeus put so much emphasis on this...
Pitcher size: I have seen a lot of variation in pitcher size throughout the range of purpurea available in cultivation and I have some plants from Pakim Pond New Jersey which have larger pitchers than burkii... as far as pitcher proportions go, again this can be very variable, even on the same plant throughout the various seasons.
Lip size? Absolutely not. Again, look at other species such as leucophylla and flava where there is an enormous variation in the thickness of the lip.
Barry, I have got a copy of the molecular studies paper now and have had a good look. Yes, it does show burkii as separate to the other purpureas. BUT it also shows that there is no differentiation amongst the rubra complex, not even at subspecies level, so they are all just Sarracenia rubra (even alabamamensis and jonesii). It also shows no differentiation between rubra and oreophila, so should oreophila now be lumped in with rubra? Therefore we have to be very cautious about quoting extracts of this paper just to suit certain species if we ignore the implications for the others. What it does show is that the genus is still relatively new and actively evolving and so we have to be very cautious and coming up with brand new species...
regards Stephen
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Post by mannyherrera on May 8, 2007 12:44:11 GMT
Hi Dave. Thanks for bringing this up. I have been trying to sort out the purpurea in Georgia question for some time. I have seen people with purps labelled "Georgia", but they have no idea where they came from. I'm not looking for exact location data, just general range info. Does purp venosa grow only in nw GA? If then, is it only the var montana form? I remember ABG doing something with purps from north GA. It seems the only purps in GA are found in the northern part of the state. Are there two forms? Or does var montana not grow in GA? I have never come across any purps in the southern portion of the state. And if there are any there, I assume they would be different than the northern GA forms. Perhaps a little more resembling of rosea. Sorry for all the questions, but this is a subject that interests me.
P.S...I've never seen any purps in MS or LA either.
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Clint
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Post by Clint on May 8, 2007 12:58:45 GMT
I think it's somewhere in the Chattahoochee national park. var. montana I mean. We live just a little way's south of the park and I considered going ... but then I remembered it's big and there are bears and I said screw it
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thwyman
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N=R* fs fp ne fl fi fc L
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Post by thwyman on May 8, 2007 13:36:42 GMT
ABG works with var. montana in N. Georgia. Not sure but I think there are 2 seperate populations.
I do not know it there are other non montana forms in GA
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Post by BarryRice on May 8, 2007 15:43:59 GMT
Hey Folks,
My understanding is that there is only one site each in Georgia and South Carolina that has the var. montana plant. I don't recall if it occurs in Tennessee. The bulk of its occurrences are in North Carolina. Barry
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Post by BarryRice on May 8, 2007 15:53:53 GMT
Barry, I have got a copy of the molecular studies paper now and have had a good look. Yes, it does show burkii as separate to the other purpureas. BUT it also shows that there is no differentiation amongst the rubra complex, not even at subspecies level, so they are all just Sarracenia rubra (even alabamamensis and jonesii). It also shows no differentiation between rubra and oreophila, so should oreophila now be lumped in with rubra? Therefore we have to be very cautious about quoting extracts of this paper just to suit certain species if we ignore the implications for the others. What it does show is that the genus is still relatively new and actively evolving and so we have to be very cautious and coming up with brand new species... regards Stephen Hey Stephen, I'll be the first to admit that I've no certain answers here. I think this is a case where our human attempts to pigeonhole plant populations into separate species, subspecies, etc., is sometimes akin to arguing about angels dancing on pins. I am very, very willing to allow that I am not necessarily correct! Cheers Barry
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Post by mannyherrera on May 8, 2007 16:06:40 GMT
Thanks Barry. I wasn't aware that var montana existed in SC. Apparently oreophylla does (or once did) occur in TN. It would be great to discover purp and oreo stands in TN.
That being said...are the purps found in West Virginia venosa? I've seen photos and they don't look like purp purp.
Purpurea is definitely the most variable species there is.
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Post by Dave Evans on May 9, 2007 2:56:19 GMT
Dear Stephen, Specifically, the paper shows that different species of Sarracenia are more similar to each other with regard to the genes tested than S. rosea is to the other, northern S. purpurea. It shows they are more different, not less different. It is all about the structure: Sarracenia rosea: and coloradocarnivorousplantsociety.com/Sarracenia_purpurea_ssp_venosa_var_Chipola.htm(The plant at the above link appears to have some S. psittacina in it, but it might just be variation within S. rosea.) Sarracenia purpurea: Good Growing, Dave E. I have to say that I do not agree with the Sarracenia rosea name, and I'm still not sure exactly what is supposed to make this purpurea different to all the others...? Barry, I have got a copy of the molecular studies paper now and have had a good look. Yes, it does show burkii as separate to the other purpureas. BUT it also shows that there is no differentiation amongst the rubra complex, not even at subspecies level, so they are all just Sarracenia rubra (even alabamamensis and jonesii). It also shows no differentiation between rubra and oreophila, so should oreophila now be lumped in with rubra? regards Stephen
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Post by BarryRice on May 9, 2007 17:35:59 GMT
Thanks Barry. I wasn't aware that var montana existed in SC. Apparently oreophylla does (or once did) occur in TN. It would be great to discover purp and oreo stands in TN. That being said...are the purps found in West Virginia venosa? I've seen photos and they don't look like purp purp. Purpurea is definitely the most variable species there is. Hey Manny, Yeah, var. montana occurs in one spot in South Carolina, and it takes a heck of a hike to get to the plants. I have a trip description in which I mention the site: www.sarracenia.com/trips/ncsc2005/im38.htmlThe S. oreophila site in Tennessee is disputed. SUPPOSEDLY a pitcher plant was collected in TN, brought to the University greenhouse, but killed accidentally. Even more accidentally, the dead plant was discarded and not made into an herbarium specimen. So all we have today is word of mouth. The Virginia plants are supposedly subsp. venosa, but the ones I've seen were almost intergrade-like in some characters: www.sarracenia.com/trips/vanj2002/im07.htmlCheers Barry
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Post by gardenofeden on May 9, 2007 19:18:51 GMT
what, the Neyland paper? I don't understand what you mean Dave your pictures to me contrdict your point about structure, apart from flower colour I see very little discernible difference between the plants shown. How would you describe the difference? Dear Stephen, Specifically, the paper shows that different species of Sarracenia are more similar to each other with regard to the genes tested than S. rosea is to the other, northern S. purpurea. It shows they are more different, not less different. It is all about the structure:
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