Every serious succulent grower knows that cacti are a pain in the butt to identify, but I have one that is a special challenge. I bought this cute ball-shaped cactus on sale at Home Depot and took it home to begin its rehabilitation. When I picked it up at the store, I discovered that it had not one, not even two or three, but FIVE apexes (or apices, to be grammatically correct). I did some research and discovered that this is a rather rare mutation for globose and subglobose cacti. I am tempted to think it's a Mammillaria because of the tubercles, but it has stiff, 1/4" central spines I have never seen on a Mammillaria. Rebutia, maybe? You can see in the middle where I had to pick off the hot-glued strawflower; fortunately, it wasn't on top of a growth point. Anyways, the multiple apices have distorted the growth pattern a bit, so it should be a bit more of a challenge for all you cactus identifiers. I have tried to attach pics, so have fun if you can see them!

Here is a link that might be useful: My Mutant Cactus Pics