Spider Cactus (Gymnocalycium denudatum)

Spider Cactus
Gymnocalycium denudatum

A closeup.

franj,
Nice specimen you have there, I like the spination.
I believe this cactus you have is one of the 'varieties' of G. denudatum.
The book "The Cactus Family - 2001" states that the flowers on the base type species are "pure white". It also says that the species is also "extremely variable"....hence the abundance of known varieties.
I know desert-tropicals dosen't list all of the known varieties nor does any one source, but I'll do some google searching for a variety that has your flower color and spine pattern in hopes to nail down a variety.

(Just for future reference here are the links to the other three photos you posted of this plant)
http://davesgarden.com/guides/pf/showimage/167754/
http://davesgarden.com/guides/pf/showimage/167755/
http://davesgarden.com/guides/pf/showimage/167757/

Thanks Xeno,

Joan from Admin at first questioned it too. I pointed out that both Desert Tropicals and Cactaceae.net show pink and white flowers and Desert tropicals says "White to Pink". I did a search for a couple of the varieties and subspecies listed at Daves and the only references I found to them were on an obscure Euopean site. No descriptions, no pictures. So I quickly gave up. I wonder if all the ones listed here are even valid.

However if you can find a subspecies or variety that fits, keeping in mind it would have to be common in cultivation, I will request that the pictures be moved.

Thanks,
Dave

I googled each and every one of those varieties listed in the PF and didn't find a 'variety' name that matched your spination and flower color. But what I did find was a list of every variety throughout history from many different book publishings listed at this site here:
http://uc.privat.t-online.de/taxa.htm
The varieties listed in the PF are also listed in that website with the Authors of the books and the person who described it and the year it was described, which shows that they are valid. Even though one may not be able to find a written description or photo 'online' of a certian plant, we have to resort to books, which is where the original plant was originally concieved and published most of the time validly. It originates in books first of all and then gets filtered down to the internet and the rest of the population.
Most of the cacti sold in outlets, the grower dosen't bother researching the variety/form/cultivar anyway, it is up to us the collectors to find out which one it is (If at all possible)
I have found that many of the European and Oriental sites are more thorough with the taxonomy regarding varieties, formas and cultivars of Cacti, which I think is good.
Hopefully this will atract more international gardeners/collectors/enthusiasts to join DG and and share thier expertise, which I am sure there are quite a few experts out there in the world other than in the USA alone. I have been seeing more and more new DG'ers over the past few years joining that are not in the USA.
Since you or I don't have all those books that describe all those varieties, and we didn't find it online, I guess it's fine where it sits in the PF (until someone else comes along ID's the variety).
I have come across the same situation when I am trying to ID a certian subspecies or variety, and when I am not able to ID it (because I don't have every book thats ever been written on Cacti), then I put a note in the caption that I was not able to ID the particular variety.
Anyway....I like the spination of this plant and it is one of my favorite Gymno's because of it.

I researched every one of those G. denudatum varieties and found many that were either synonyms of a different species, or no longer valid, or not very popular, and have suggested that they be removed. Some of them turned out to be synonyms of D. paraguayense.

This message was edited Sep 25, 2007 10:10 AM

I sent you a reply to the mail you sent me about G. anisitsii. I think it applies here also.

Dave