Mamm ID???

Look familiar? Tall head is 3½" wide.

Hi, and welcome to the Forum.

I would suggest that it is a plant from the Polyacnthae series, but which one?

My first thought was M. spinossissima, maybe the subspecies tepoxtlana, otherwise known as M. crassior, but the spines look a bit whiter, and a bit lower in number than the description. I have seen that this species varies a lot, so it is my most likely bet at the moment.

My next thought was M. backebergiana ssp. ernestii, but that tends to grow with thinner stems than your plant. I also wondered about a straight spined form of M. rekoi as well.

Maybe others can do better, as this one has me somewhat puzzled!

Was the photo taken in habitat - if so where? as that would help narrow down the solution - or in a very nice rock garden?

Thank you, the plant is a new addition in my yard here in the Sonoran Desert, which features about 20 Mamms, 80+ other assorted cacti, and nearly 200 Agaves. I am an Agavephile myself, but have a peculiar affection for Mamms, as well. My first thought upon seeing this plant, was that it reminded me very much of my M. spinossissima, but of course it's too thick, so a thicker subspecies makes a lot of sense to me. From the pics I've just seen and as you suggest, it doesn't look quite right though, does it? Small spines are white as white can be. I'll be sure post additional pics when it blooms, though I'm not sure when that will be, since the plant is new to me.

Perhaps this will help?