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Christian

Drosera dielsiana

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Dear Will,

Are you sure of their pedigree? The differences actually are pretty obvious...

I have buy this all from very respectfull and honest sellers,for so far i can see on the forum.so i am allmost sure this are good named plants :thumbsup: It s what i say i think ,i am not buzzy long anoufh whit this plants for see really difference .

And i have no book whit fotos and discripsions from all this different plants in cultivation,so i can not check the difference.On pfotofinder is the difference of the same plants to big for seeing anything.i think there are many wrong plant pics on this,or the difference between same species is very big and this make it even more difficult to see.

I see difference between many plants ,but there are many ,i see no match difference between whitout flower,some plants looks really allmost the same to me,it s meaby the little details i still not seeing? :blush:

Like sarra purpurea,i have a few locality forms that looks like venosa,and a few venosa that looks like purpurea.Whats the difference between venosa and venosa burkii,i see no difference between .Meaby venosa montana have another lidshape ?But thats all? i still must learnt a lot or buying a glass! :blind: but i think the first,

Cheers Will

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Dear Drosera-lovers,

Please excuse that I did dig out this old thread - but there's so much speculation about the ID of Drosera dielsiana (and so many wrong assumptions proposed ;)) that I thought it is better to reply here instead of starting a new thread.

First of all: the true D. dielsiana *is* in cultivation since a long time, but unfortunately it is still not grown by its correct name. Plants currently grown as "D. spec. 4 South Africa" or "D. spec. 'pretty rosette, Africa" - these are the real thing, they match the type of Drosera dielsiana. Most likely these two plants/strains in cultivation are the same, as both normally display abberant 6-petalled flowers, and the first flower is always borne on a very long pedicel. Despite these two abnormal characters (which probalby arose in cultivation? I know that they are in cultivation in Germany since the early 1980's at least...), these plants perfectly match the type specmines of D. dielsiana.

Second: Everything in cultivation (>99% of all plants) labelled as "D. dielsiana" actually belongs to D. natalensis. D. natalensis is quite variable morphologically, regarding the size of the rosette, the width of the petiole, and the numbers of stigmas. This is not surprising, as it is a widespread species, occuring from the Eastern Cape all across eastern Africa to Zimbabwe and Madagascar. However its seeds are always fusiform, with two narrow lateral appendages (David E., "testa" is not only referring to these appendages, but testa is the entire seed coat. ALL Drosera seeds have a testa, otherwise they would be naked embryos ;)). Drosera natalensis is very closely related to D. aliciae, and both species are very, very difficult to tell apart where their ranges overlap in the Eastern Cape.

ALL photos shown in this thread (except the blurred ones showing an entire display of Drosera, including 6-petalled D. dielsiana) are D. natalensis - even these which obviously look slightly different are still all different forms of D. natalensis.

Drosera dielsiana is a relatively small plant, and certainly has the tiniest rosettes among all South African Drosera (small specimens of D. trinervia might rival them in size). It always has roundish dark black seeds, lacking any appendages, unbranched (but spoond-shaped) stigmatic tips, and a comparatively thick, densely glandular scape (thus resembling D. trinervia from some distance, and indeed this species was first mistaken for D. trinvervia before it was described as distinct species, D. dielsiana).

All plants of D. dielsiana which I know in cultivation have the first flower borne on a very long pedicel, and generally display 6-petalled flowers. However I assume that these mutations do represent the clonal inbred lines we grow in cultivation, as multiple herbarium specimens I have seen from several locations had perfectly normal 5-petalled Drosera flowers.

All the best,

Andreas

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So basically, there are no good examples of D. dielsiana in cultivation?

Someone just tagged a smallish D. natalensis with smaller seed appendages as "D. dielsiana". I've already felt this is the most likely scenario for a while.

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Most of them still look like D. natalensis to me. Notice the seeds still have appendages.

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And what about the elusive Drosera x snyderi? Is it a natural hybrid between D. nidiformis and D. dielsiana (or D. natalensis!), or a man-made one?

And where was it published? I don't find anything... I'm going to thinks that's a nomen nudum.

Thanks

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http://www.bestcarnivorousplants.net/index.php?node=product&id=4168-drosera-x-snyderi-drosera-dielsiana-x-d-nidiformis-15s

http://www.cpphotofinder.com/drosera-x-snyderi-3605.html

its really a nomen nada :) There is no description and no type. It was intended as an informal name, I believe.

I also believe the ID of D. dielsiana as one of the parents is wrong, it was a D. natalensis x D. nidiformis. At the time, D. n. didn't even have a name, though and was called sp. maglisburg. And there was a lot of speculation about D. nidiformis itself being a hybrid as it is intermediate of D. collinsiae and D. natalensis/dielsiana.

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Thanks Dave and Marcel for your help and informations.

Dave, I've seen your links before I ask the question, and for me, its don't answer completely... That's why I use this topic to complete the informations. I think I have now what I want! (Or solely what I can...)

But your last observation is really precious: D. x snyderi is itself one of the few fertile Drosera hybrid, if one of the parent have also an hybridogenic origin, that could maybe explain the polymorphism of South African sundews? We have perhaps "young" species, not compltely distinguished? Like most Nepenthes species...

So, the ball is in the court of taxonomist like - I suppose - Andreas Fleishmann or Fernando Rivadavia who works in the future monography of the genus Drosera! So, courage...

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Thanks Andreas! My friend is often asking me to determine whether he has D. dielsiana or natalensis... now i know what to tell him :-)

BTW: what is D. spec. Chimanimani Mts. (Zimbabwe)? Is it D. natalensis? In such case, it is quite different from the typical one.

Adam

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Hi Adam,

yes, the plants from Chimanimani Mts. (Zimbabwe) should be D. natalensis but it´s really hard to believe that after the ´Debbert´ form looks completely different. :confused:

Best regards,

Dani

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But your last observation is really precious: D. x snyderi is itself one of the few fertile Drosera hybrid, if one of the parent have also an hybridogenic origin, that could maybe explain the polymorphism of South African sundews? We have perhaps "young" species, not completely distinguished? Like most Nepenthes species...

Well, rather similar. The genus Drosera is quite old and well differenciated, but there are two branches, one in South America and one in southern Africa that have very closely related species. So closely related they produce fertile hybrids, like Nepenthes.

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what grow as D. dielsiana, Should I change the label?

Mutated six petal flower

D_%20dielsiana.JPG

normal flower

D_%20dielsiana4.JPG

D_%20dielsiana3.JPG

Look at the styles! Finally, undivided styles! That is a dielsiana trait!

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