I think it is magnimamma, as they are quite variable, but I'll let the experts put in their 2¢.
Amy

Hi Dawn, it fits the call okay, bear in mind that magnimamma is highly variable in spine length, colour and number, also magnimamma has a number of synonyms... which serves to add to the variability. M. bucareliensis for one, has dark spines.

Cheers, CP

Ok, M. bucareliensis fits better but, what about the upward curving spines? I thought the spines were supposed to be downward.

Dawn

M. bucarilensis is now considered just a synonym for M. magnimamma.

Sorry Dawn, we had lost of visitors coming and going yesterday, so I kept losing the thread of what I was doing as I tried to check my books etc to try to find an ID for this plant... so by the time I posted my reply, I'd left a few things unsaid as I continued to ponder the possibilities.

You are right, magnimamma and all it's forms usually have a downward pointing central, this is the thing that has me puzzled.
There are a number of other species that I've been looking at that have an upward pointing centrals, and dark spines such as... brandegeei, fera-rubra(forms), johnstonii(sancarlensis) etc., but these all have other features that yours does not have, such radial spines and lack of wool in the axils.
The spines on yours are all subcentral and there are no radials which is a feature of magnimamma, magnimamma also can produce lots of wool when it is young, and tends to lose this when it is older.
Some of the older spines at the base of you plant are much stronger and longer than the spines on the top of the plant, which would indicate to me that it was grown a lot harder when it was young... it will be interesting to see how they change after a couple of seasons in your collection.
So I'm no closer to solving it apart from the distinct possibility of hybridisation.

CP

Thanks CP. That was my next thought, possibly a hybrid. I guess it will come down to the flower. Everything else says mamm except for the upward spines. That is what is confusing me most. A plant for .94 cents with black spines is a keeper for me. Thanks for all your help.

Dawn

Some varieties have the longest spine curving up, or even a couple of long spines, one going up and one going down.

The tubercle shaper matches, the overall spine count and colour matches, the wool matches. You can check for latex if you like.

You might also want to look at the M. polythele group, perhaps ssp durispina. The tubercles would be conical though, and you'rs look to be pyramidal.

ssp. durispina is one that I looked at, but those long spines at the base of your plant look a bit too long, (unless I've got the dimensions wrong)... ssp. durispina has no central spines, 6-8 radials - lower and lateral ones to 7mm and upper one to 15mm (and according to Pilbeam should be straight). Another feature of durispina is that while they are wooly, there are no bristles, which are present in yours. Flowers of durispina are the typical carmine colour of most Mamms, whereas in Magnimamma they vary from deep pink to yellowish.

Happy growing... CP

I measured the longest spine and it measures 1 inch. I checked for latex and it does have it.

Thanks,
Dawn

Looks like a duck, sounds like a duck, smells like a duck, must be M. magnimamma :)

Yep! LOL.

CP