Graptopetalum and Pachyphytum puzzles

[ralphrmartin]

I've got a couple of Graptopetalum puzzles, and a couple of Pachyphytum puzzles, concerning names and identity.

Picture (1) shows two plants, both supposed to be Graptopetalum pachyphyllum, and I think they are. But, under identical growing conditions, one has many small heads, while the other has fewer large heads. Is one a selected cultivar, maybe 'Blue Bean'? I presume the bigger one is probably polyploid perhaps, with more copies of genes, so stronger growing - is such a form documented or named?

Picture (2) shows 2 more plants. The left one I acquired as G. mendozae. The right one is unnmaed, but John Foster kindly suggested that it might be G. mendozae. They don't look very similar. So which, if either (or both), is G. mendozae, and what then is the other?

Picture (3) shows 2 plants both acquired as Pachyphytum machucae. Again, they don't look very similar. So which, if either (or both), is Pachyphytum machucae, and what then is the other?

Picture (4) has the opposite problem, two Pachyphytum plants which look pretty much identical, but acquired with 2 different names - P. uniflorum, and P. hookeri 'blue form'. Which name, if either, is correct (or are the plants really different), or is it just a lumping / splitting issue?

[Liz M]

The first pictures, Graptopetalum pachyphyllum is what both are. I would say that, that on the right has two years growth, with last year being the long stemmed and this year's being the short stemmed new growth. Apparently it grows into a sprawling mat, which certainly reflects the right photo of the pair. The left may just show more compact growth.
Second pictures, Graptopetalum mendozae is the one on the right, it is the same as mine. I'm not sure what the one on the left is.
Third pictures. The righthand one is Pachyphytum machucae, the left could be Pachyphytum caesium.
Fourth pictures. Pachyphytum hookeri and uniflorum are synonymous, with hookeri being the curent one used.
I don't know all this, although I have some of these and are very interested in them, but got the information from the International Crassulaceae Network, which is extremely informative and invaluable for Crassulaceae enthusiasts.
http://www.crassulaceae.ch/de/internati ... ted-plants

[ralphrmartin]

Thanks Liz - and indeed the International Crassulaceae Network is a very useful reference source.

First picture - note that it is not only growth habit. The leaves are at least twice as big on the left hand plant, while they never get any bigger on the right hand one (from John Foster). (Both plants are the same distance from the camera). Anyway, I do think they are both G. pachyphyllum.

Second picture - then you agree with John Foster about the right hand one, and I have perhaps been sold a pup with the one on the left. Perhaps it's a Pachyveria?

Third picture - thanks. I think I agree with your suggestion here.

Fourth picture - as surmised, probably a case of lumping / splitting.