Rebutia is a genus of about 60 species of cacti native to Bolivia and Argentina.  Hardy and easy to grow, these popular cacti are generally small and globular, with relatively large and attractive flowers that are mostly yellow to red in colour.  They like a position in strong light and should be watered regularly in Summer, being allowed to dry out completely between waterings.  They are excellent in the garden and are particularly well-suited to pots.