Native to the Cochabamba Valley of Bolivia, Rebutia mentosa is a nicely spined clumping cacti with heads 2.5 inches across. It's a heavy clumper and produces a nice patch over time. The flowers are a very deep magenta.
      From Bachs Cactus Nursery, This one is full grown and starting to pup at the base. The flowers came in May.

Flowers in May	A little closer	Closer still	A solitary one a week later
A closer view