It's all your fault, really

First, a confession: I am cheap, and I hunt for pretty Mammillaria on garden centres, supermarkets and flower shops. This serves several purposes - the hunt in itself is lots of fun, I increase my collection with nice and inexpensive plants AND I exercise my meagre identification skills in an attempt to put a name on their labels other than the boring "Mammillaria sp."

This one struck me as curious when I bought it (without flowers) because of the hooked centrals, which have all but dissapeared since then. When it eventually flowered, I tentatively ID'd it as M. phitauiana, but seeing the recent pictures of M. neopalmeri and M. buxbaumeriana had me seriously doubting my initial ID. What do you think?

Its M.phitauiana.

I think you are right with M.phitauiana. But i'm astonished you got this plant in a supermarket.
M. neopalmeri don't grow cylindric. And M. buxbaumeriana has no hooked spines.

Here is a plant I found south of La Ventana in Baja California. It looks like yours.



Robby

Thank you, Tam and Robby. I don't know why, but one particular garden center near Lisbon has, sometimes, amazing cacti for sale at 1€ or little more. On one occasion I found there two Gymnocactus, one plant of Gymnocactus viereckii and one hybrid. I asked the guy where did he buy his cacti from, but he was rather evasive. That's where this plant came from.