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D.meristocaulis ***IS*** a pygmy sundew!!


Fernando Rivadavia

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Hello to all,

I just wanted to share with everyone the latest news about D.meristocaulis -- news which will throw open discussions about the spread of CPs and plants in general... I've just received results of DNA sequencing which puts D.meristocaulis NOT as a close relative of pygmy sundews or of the pygmies and petiolaris-complex species. To our total surprise, it appeared AMONG the pygmies, as a full member of subgenus Bryastrum, somewhere between D.scorpioides and D.ericksoniae!!!!!! Needless to say we are aghast with these results and are trying to fathom the depth of what this means...

Best Wishes,

Fernando Rivadavia

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Hi

For a start it implies pygmies have not evolved at all since the landmass broke up....

I would have thought it shows the opposite , Meristocaulis doesnt produce gemmae to my knowledge so it has adapted along a slightly different path to Australian pygmy even with it proving to be a genuine member .

Wonder if this will open up possibilities for hybrids with orther pygmys.

regards

Belinda

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I was under the impression that nobody yet knows for certain whether it produces gemmae, although I suppose based in Fernando's news it is perhaps likely that it does. I certainly hope that it does; it will increase the chances of the species making its way into my collection sooner rather than later!

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For a start it implies pygmies have not evolved at all since the landmass broke up....

I think flowering plants largely evolved after the continents broke up. I dont know how far back pygmy sundews are throught to have evolved, but seems much more likely that, somehow, at some point, a pygmy seed must have made the trip across the ocean... Presumably not too long ago or we would have more than one pygmy over there...

Quite a conundrum that one

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Hi guys,

What this data shows is that D.meristocaulis is much more closely related to pygmies (it's one of them!) and reached S.America not too long ago, certainly after the breakup of Gondwana. How? Birds, wind, ocean currents, who knows!!!!

Since its arrival, it has indeed evolved in comparison to pygmies, adapting to its new habitat:

- The flowers lost their scapes.

- The plants seem to form longer stems.

- Gemmae are apparently not produced, BUT now that we know it is a pygmy, I wouldn't doubt it if it does in fact produce them, although possibly only when stressed or something. Considering how much seed D.meristocaulis produces and how little is produced by most pygmies, it appears that it may have switched from a mainly assexual reproductive mode (gemmae) to a more sexual mode (seeds).

Belinda mentioned hybrids with other pygmies... wow that would be amazing if possible!!!! Certainly worth a try with D.scorpioides, D.lasiantha, D.dichrosepala, and other erect species as soon as plants start flowering! How are yours doing Belinda?

As for the costs, yes it was certainly mostly mine and other's private funding, but the most costly part was going Neblina. As for that, the whole CP community has contributed by buying seeds, so thanks to all who did. ;-)

The lab costs are also pretty steep, but I’ve managed to get reactions done by friends in parallel with their own work, and thus keeping costs down (but losing time as a result -- remember I returned from Neblina 7 months ago...).

Best Wishes,

Fernando Rivadavia

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Wow, that is amazing news Fernando! It would be interesting to see if it does produce gemmae at all, perhaps under extreme conditions as a "last ditch" survival mechanism as you say may happen! Anyway, thanks for intoducing such a fascinating and wonderful species into cultivation. I'm glad that D.meristocaulis was refound at last!

As an aside, does anyone know if seed of this species is still available from any source? And if so, where?! I'd love to have a go at cultivation! :D

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What I find interesting is that it has not only made it from Australia to South America, but from WA to the other side of South America. I find it strange that a species closely related to D. scorpioides has evolved at such a distance away and yet on the eastern side of Australia the only species present is the diminutive D. pygmaea. I wonder why none of the larger growing species never established themselves in the east of Australia yet could travel across a continent, an ocean and another continent to successfully do so.

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Hi Fernando and all!

First of all, congrats to your fantastic phylogramm! Well, now we've got molecular prove for D.meristocaulis belonging to the pygmies, a fact some of us already had a premonition of by comparing them morphologically! ;-)

Fernando, when stating that D.meristocaulis clustered somewhere between D.scorpioides and D.ericksoniae, you should have mentioned that you "only" sequenced 4 representatives of the pygmies. Some German CP forum user did not notice your "somewhere" and misunderstood that those 2 pygmies were the next relatives of D.meristocaulis... ;-)

I could imagine that all australian pygmies (including D.pygmaea which belongs to section/subgenus Bryastrum in my opinion, too. 4-merous flower only is no reason for creating a own section sensu Diels or Schlauer I think) will be closer related to each other than any of them to D.meristocaulis! Maybe additional genetic markers will show! ;-) But morphologically and geographically, it's somewhat isolated from the pygmy-rest. Thus I would propose a subgenus Bryastrum section Meristocaulis for D.meristocualis instead of it having its own subgenus sensu Schlauer. (And at the same time, deleating section Lamprolepis thus all pygmies would fall into the same subsection. I think there's still some work to do to gather more information about the interior structure of this Drosera section! ;-) I predict at least (!) a distinct "Drosera-pygmaea-occidentalis-microscapa(-nitidula?)-group", the "stem-forming-ones"(i.e. D.scorpioides, D.barbigera, D.lasiantha etc.), the "D.pulchella-platystigma-mannii-ect.-group") at section level...)

All the best,

Andreas

All the best,

Andreas

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Hello again!

Adam, you can still get seeds of D.meristocaulis from Allen Lowrie.

>What I find interesting is that it has not only made it from Australia to South America, but from WA to the other side of South America. I find it strange that a species closely related to D. scorpioides has evolved at such a distance away and yet on the eastern side of Australia the only species present is the diminutive D. pygmaea. I wonder why none of the larger growing species never established themselves in the east of Australia yet could travel across a continent, an ocean and another continent to successfully do so.

Makes you wonder if at one point in time pygmy Drosera weren't more widespread than they are today...

>Fernando, when stating that D.meristocaulis clustered somewhere between D.scorpioides and D.ericksoniae, you should have mentioned that you "only" sequenced 4 representatives of the pygmies. Some German CP forum user did not notice your "somewhere" and misunderstood that those 2 pygmies were the next relatives of D.meristocaulis...

As far as we can tell they are! :):)

I agree that D.pygmaea doesn't deserve its own section, but what the rbcL sequence seems to show so far is that D.meristocaulis may NOT be basal to pygmies, but WITHIN the pygmy clade. That is, a monophylletic pygmy clade would have to include D.meristocaulis, which may make separation of D.meristocaulis into a different section/ subgenus artificial.

Like you, I also see deeper divisions among pygmies and a possible classification into 3 or more sections. But D.meristocaulis may belong to one of these possible sections, including D.scorpioides, D.lasiantha and other erect species.

Take Care,

Fernando Rivadavia

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  • 3 weeks later...
  • 3 years later...

This thread was referenced in another recent post and got me to pondering.... Are there other Drosera which have apparent long-distance relationships like D. meristocaulis & the pygmies? D. sessilifolia & D. burmanni come to mind - another odd South America / Oz combo. Others?

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  • 3 years later...

Congratulations Fernando! I have just took a quick view on the article and i must say, that i still cannot believe it! But the proofs are quite obvious and the phylogenetic analysis shows it clearly... I will have to get use of it :smile:

Congratulations once more, great work

Adam

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Aymeric, shoot me your email address and I'll send you a copy of the paper. We explain it by long distance dispersal, which is what can be assumed for D.sessilifolia as well, having taken a similar path.

F

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  • 6 months later...

I must apologise but I have to point out this particular tree doesn't highlight D. meristocaulis' position among the pygmies but kinda suggests it is sister to all the others. From this, inclusion with/exclusion from subgenus Bryastrum becomes a little arbitrary. Have you got another figure you are able to share?

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Yes, you are correct, this tree does show it as a sister branch. Then again, we need to add a lot more pygmies to the tree, ;)

Read the paper and you'll see there are several other characters that place D.meristocaulis among the pygmies (chromosome number, pollen, glands...). The only characters that differ are the lack of gemmae, sessile flowers, and geography.

Either way, D.meristocaulis is at least very closely related to pygmies - much more so than any other sundew. And *that* is the truly amazing thing about this species, considering where it grows.

Best wishes,

Fernando Rivadavia

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