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McPherson's burkii


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#21 Alexis

 
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Posted 15 March 2012 - 23:58 PM

Well this is where we start where we began Dave. Is rosea distinct enough from venosa? You're making the point that it has become geographically distinct from venosa, but again it's degrees of separation. If rosea was found in Brazil instead I might agree, but we know that the two grew as closely together as venosa and purpurea until humans destroyed their habitats.

#22 Dave Evans

 
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Posted 18 March 2012 - 03:17 AM

Well this is where we start where we began Dave. Is rosea distinct enough from venosa? You're making the point that it has become geographically distinct from venosa, but again it's degrees of separation. If rosea was found in Brazil instead I might agree, but we know that the two grew as closely together as venosa and purpurea until humans destroyed their habitats.


Yes, it is different enough from venosa not to be a part of it. Please read:
http://www.sarraceni...aq/faq5542.html

#23 meizwang

 
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Posted 19 March 2012 - 23:26 PM

Well this is where we start where we began Dave. Is rosea distinct enough from venosa? You're making the point that it has become geographically distinct from venosa, but again it's degrees of separation. If rosea was found in Brazil instead I might agree, but we know that the two grew as closely together as venosa and purpurea until humans destroyed their habitats.



There seems to be a lot of variation in S. rosea, from one population to the next. In baldwin county, there were some individuals that looked like venosa, but a few feet away, others looked more like S. rosea. No doubt, environmental conditions also affect the physical appearance of clones. I bet an individual clone can look more rosea-like during one season, and then the exact same individual can look more venosa-like during another season. Who knows-maybe s. rosea interbred with S. purpurea ssp. venosa 100's of generations ago when they had a closer common ancestor, but the S. rosea strain was more adapted to the southern environment.

With so many generations of breeding and so much time for mutations to occurr, it's tough to pinpoint the truth. Keep in mind results from allozyme analysis requires interpretation of data, so when one says S. rosea is backed up by hard science, the reality is it's backed up by someone's interpretation of hard science. However, S. rosea is a lot easier and less labor intensive to write on tags versus writing S. purpurea ssp. venosa var. burkii, so whether it's right or wrong, it works for me :flag_of_truce:

#24 Dave Evans

 
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Posted 20 March 2012 - 03:24 AM

There seems to be a lot of variation in S. rosea, from one population to the next. In Baldwin county, there were some individuals that looked like venosa, but a few feet away, others looked more like S. rosea.

There is actually a lot more of this happening between S. purpurea venosa and S. purpurea purpurea. Are there S. purpurea venosa and S. rosea which look similar? I'm not really sure about this... At a glance they might look similar, but the longer you look at them the more you'll find they just aren't consistent. I've literally reviewed hundreds of plants in situ and in cultivation at Meadowview.

I've looked at plants in southern Georgia, Florida and Alabama. I've personally been unable to locate a single example of S. purpurea venosa. They don't even grow the same. Not in the same micro-niche purpurea like it wetter, nor in the clumping habit you see so often with S. purpurea. So I started researching and found out about S. rosea. S. rosea also looks waxier than any other Sarracenia. New pitchers on most plants can often look waxy, but on S. rosea, they stay waxy looking nearly the whole time. BTW, I didn't even see them in flower and noticed how different they are, but I did notice the dead or ripening flowers from the year or season before.

Edited by Dave Evans, 21 March 2012 - 00:27 AM.


#25 Alexis

 
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Posted 20 March 2012 - 11:05 AM

Yes, it is different enough from venosa not to be a part of it. Please read:
http://www.sarraceni...aq/faq5542.html


I agree, which is why I support a new subspecies of purpurea, not a whole new species, or a variety of venosa.

#26 meizwang

 
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Posted 20 March 2012 - 17:15 PM

I've looked at plants in Georgia, Florida and Alabama. I've personally been unable to locate a single example of S. purpurea venosa.



Hi Dave,

Would you consider these S. purpureas from Georgia S. purpurea ssp. venosa? This population from Evans/Tattnall Co, GA is reported as the southern-most range of S. purpurea venosa:
http://www.flickr.co...in/photostream/
http://www.flickr.co...in/photostream/

and here's a spectacular shot:
http://www.flickr.co...gdr/3602396420/

They almost look a little montana-ey to me, if that's a word.

Edited by meizwang, 20 March 2012 - 17:38 PM.


#27 Dave Evans

 
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Posted 21 March 2012 - 00:20 AM

Yes, I've found S. purpurea in Georgia, but only in the north. In the south there is just S. rosea. I editted the post.

It's the very bold thinner red veining, basically it is the same color pattern as for S. flava var. ornata, but on a purp. I swear, these are just color morphs which should be placed as forms, not varieties. Both forms and varieties are found within larger populations of species and/or subspecies. Species and subspecies have different ranges from each other, while forms and varieties are found mixed in those populations... No one has demonstrated S. purpurea venosa var. montana is "different" from S. purpurea venosa! Why give it a different name based on location? This situation it is better to name a cultivar as being from that location rather than "invent a taxon". Especially if that "location" is a smear from the Appalachians down to sea level... If it is A) morphologically different and B) it has a different range it is a subspecies, not a variety. If S. purpurea venosa var. montana is consistenly as different as Schnell claims and it has different range, it is a subspecies.

These plants don't show any S. rosea characteristics. They also look remarkably alike to the S. purpurea in New Jersey which is *supposed* to be a different subspecies... To me, it appears that the range of S. purpurea venosa is actually surrounded on three sides by S. purpurea purpurea.

Someone, preferably Stewart McPherson, please introduce me to a S. rosea that looks remotely like the plant in this photo, and I will be extremely impressed:
http://www.flickr.co...in/photostream/

Edited by Dave Evans, 21 March 2012 - 02:38 AM.


#28 Alexis

 
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Posted 21 March 2012 - 12:23 PM

The problem with designating disjunct populations as species and subspecies is that in a lot of cases they weren't disjunct at all. We're now looking at fragmented populations that bear little resemblance to how things were 250 years ago.

#29 Dave Evans

 
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Posted 22 March 2012 - 16:23 PM

Alexis, I'm not sure what you're directing this at specifically...? When discussing Sarracenia, I'm talking about their natural ranges, not the 3-5% left now. There used to S. purpurea growing right here in Kenilworth, but local bogs were destroyed, drained and/or filled in, and the closest populations are now over an hour drive's away. In the seventies, there was still S. purpurea in Edison, NJ--gone now.

The separation between S. purpurea and S. rosea has been in place, naturally, for thousands of years. Do note that natural feature, the Okeefenokee, the world's largest swamp/bog system, which separates them... Neither species is found in the Okee, and that is the natural state of things. But also, Alexis, the Okee is now only about half its original size so keep that in mind too.

Edited by Dave Evans, 22 March 2012 - 16:25 PM.


#30 Alexis

 
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Posted 22 March 2012 - 17:18 PM

I was referring to this Dave: "Species and subspecies have different ranges from each other, while forms and varieties are found mixed in those populations"


I just meant you can't use such a black and white rule when we don't necessarily know the full range of sarracenia only a couple of hundred year ago.

What evidence is there that venosa and 'rosea' are so separate? We know that the flava distribution was much more expansive once upon a time:

http://www.pitcherpl...natural-map.jpg

It seems likely that 'rosea' flower coloration is a result of flava hybridisation, and flava flowers are often shorter than say leucophylla blooms.

#31 Dave Evans

 
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Posted 23 March 2012 - 16:41 PM

Because they have been naturally separated, people didn't harvest S. purpurea from the Okee and replace them with non-natives, it is pretty much in its natural state; hence why it is still so valuable as a National Park.

The map of S. flava you have cited was made by using historical records of herbarium specimens. The same kind of specimens can be used to build accurate maps of previous S. purpurea and/or S. rosea populations as well. Nope, they don't go back to pre-European migrations to North America.

However, what is even more interesting is how the sea level goes up and down as ice ages occur. I suspect a large section of both S. purpurea and S. rosea range is currently under sea water and will not be available to the plants until the height of the next ice age.

#32 gardenofeden

 
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Posted 23 March 2012 - 19:29 PM

. I suspect a large section of both S. purpurea and S. rosea range is currently under sea water and will not be available to the plants until the height of the next ice age.


we're still in an ice age, just a temporary interglacial period...:sun_bespectacled:

#33 Dave Evans

 
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Posted 23 March 2012 - 21:03 PM

It seems likely that 'rosea' flower coloration is a result of flava hybridisation, and flava flowers are often shorter than say leucophylla blooms.


If rosea were a kind of S. x catesbaei, why is it absent everywhere S. purpurea and S. flava overlap; yet there are always various intergrades of S. x catesbaei? Why do the flowers have pigments found in neither purp or flava? And, I'm glad you mentioned it, even S. x catesbaei is a poor match to S. x naczii. There is a fanatic shot of S. x naczii on the cover of The Savage Garden by Peter D'Amato.

Edited by Dave Evans, 23 March 2012 - 21:14 PM.


#34 Alexis

 
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Posted 23 March 2012 - 21:44 PM

But that's like saying rubra can't be an evolution of alata (or vice versa) because of a lack of ahlsii hybrids.

It's too simplistic to say burkii is a kind of catesbaei, but if you are making the point that it is a whole new species, unrelated to venosa and that no flava genes have ever had any influence, that would be the most astonishing example of convergent evolution.

#35 Dave Evans

 
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Posted 24 March 2012 - 00:53 AM

Well, S. flava doesn't look much like S. rosea nor S. purpurea, so I'm not really following you here...

It is interesting to me how S. purpurea purpurea can sometimes appear rather similar to S. catesbaei (purp venosa * flava).

The flowers of flava are taller than those of purpurea and much taller than rosea. So where is the flava influence in the rosea flowers?

Alexis, am I reading you correctly? You're saying you're under the impression that A) S. purpurea venosa burkii has bred with another species, B) has undergone a separate evolutionary tract from S. purpurea, both venosa and purpurea and C) it shouldn't be considered a different species; even though you're affectively saying the separation is even further than the authors of S. rosea and myself for the matter...

All I see is flava and purpurea and in the south flava and rosea flower at nearly the same time of season, they hybridize frequently. However, even these F1 hybrids of S. catesbaei and S. naczii are rather different. These differences are not coming from the S. flava parent plants, not that I can see anyway...

Since the flava of both the northern and southern populations have coloration patterns matching purpurea and rosea, I think something very interesting is going on between these two. Or maybe not. Seems that S. alata also has the same various coloration patterns, so perhaps it is just something S. alata, flava, purpurea and rosea inherited from their common ancestor...

Edited by Dave Evans, 25 March 2012 - 19:06 PM.


#36 Alexis

 
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Posted 22 June 2012 - 09:03 AM

Sorry, I lost track of this thread.
This is an interesting specimen: [ur]http://www.ebay.co.uk/itm/Sarracenia-purpurea-ssp-venosa-Yellow-Flower-/200780760598?pt=UK_HomeGarden_Garden_PlantsSeedsBulbs_JN&hash=item2ebf774616#ht_500wt_1156[/url]

Alexis, am I reading you correctly? You're saying you're under the impression that A) S. purpurea venosa burkii has bred with another species, B) has undergone a separate evolutionary tract from S. purpurea, both venosa and purpurea and C) it shouldn't be considered a different species; even though you're affectively saying the separation is even further than the authors of S. rosea and myself for the matter...




I'm saying that, as purpurea spread down from the north, climatic conditions lead to rapid diversification. I don't regard that rosea has undergone a separate evolutionary tract, all I'm saying is that it's very likely that other genes from other sarracenia species have been thrown into the melting pot. The problem is that we only have a few pieces of the jigsaw left. We don't know if a population of venosa developed a mutation that lead to very short flower scapes - the genes for which persisted.