From Tres Marias Island, Nayarit, Mexico, Mammillaria mazatlanensis is a clumping globular to columnar cactus to 6 inches tall and two inches thick. It's white spines with a single red hooked central contrast nicely with the dark green body of the plant. It produces large pinkish purple flowers.
     I got this one from Tanque Verde Nursery. Can't wait to see flowers.
     Update June 2007, Flowers!

Flowers In June

A closer view

Even closer