euphorbia granulata

Ariocarpus is a small genus of succulent, subtropical plants of the family Cactaceae.

The name comes from the ancient Greek 'aria' (an oak type) and 'carpos' (=fruit) because of the resemblance of the fruit of the two genus in acorn form. Another possibility for the origin of the name is the work Scheidweiler did on the tree Sorbus aria at the time he described the genus Ariocarpus. He might have meant the fruits of Ariocarpus plants look like the fruits of the Sorbus aria.

It comes from limestone ...