What do you think?

In my collection are some nameless plants, maybe you can help to identify it. My guess it's a M. rhodantha. Do you agree?










Thanks so far for your help.

Adios Amigos
Ralf

Hi Ralf,

I believe this could be M.polythele. M.rhodantha calls for 17 - 24 glassy white radial spines which this plant does not have.

Yours, Tam

Hi Tam,

sure, of course. Sometimes I've a plank before my head. The simple things are often to far away. Many thanks for your help.

Greetings
Ralf

Wow, M. polythele is sure variable. The dark spines are a lot like those of my M. polythele ssp obconella. That's one of my few cactus that came with a name because I bought it at a botanical garden here.

May I ask while on the polythele topic. I did not see M polythele nudum on Hugo's list here. Is it not a valid name?

Shmuel

Hi all,
First off, Mammillaria polythele ssp obconella is typically a yellowish brown spined plant, and the spines are rather more curved than typically is the case with ssp. polythele. So if you have a dark spined plant, it may not be obconella, but probably just polythele. I attach a photo of obconella ML004 for your comparison.



M. polythele nudum is just a form, probably a horticultural sport, and as such doesn't warrant inclusion is a classification.

Ralf, your polythele is gorgeous and your obconella is really beautiful, Chris.
Nice photos!

I really have to rethink my polythele's.
What I thought was M p polythele now seems to be more the obconella as you described above:


Here is what was labelled obconella and probably now M p polythele:


Just for the record, here is the "nudum" which I now understand is an inermis form of polythele. How would one write that? Mammillaria polythele "nudum"?


These photos are a whole growing season ago - the plants are larger now - do they seem etiolated? They are on an east facing covered porch and get about 1 hour of very early direct sun.

Thanks again!

Shmuel

For some growers M.obconella is species in its own right but for others it is a subspecies of M.polythele and should be written has M.poythele ssp obconella. The different is , of course, is the much longer spines in obconella.
Has for nudum and inermis these are both the same plant and could be said to be a cultivated variety and should be written as ' Nudum ' or ' Inermis '

Tam.