Here's a nicely spined Eriosyce from coastal Chile (The Atacama desert). I couldn't find out much about this plant, but saw a picture of a mature plant that looked to be about 6 inches tall and 4 inches around.
     This one came from Bachs Cactus Nursery loaded with buds in spring 2006. It put out it's first flower that same day I bought it. Very cool! Eriosyce flowers are some of my favorites. I love the layered look of this one.

A View from the top

A couple days later

A closer view

One of this years flowers