Cactus collectors love the little Astrophytum star cactus, a rare find here in New Zealand. These guys come in a 9cm pot.
 
It is a spineless cactus with a chubby round body resembling a sand dollar. Star cactus plants are easy to grow and make an interesting part of a succulent or arid garden display. If you get your hands on seeds, start them in seed flats with a sandy composite soil mix. Keep the soil moist until germination and then move them to a sunny location with protection from the noonday sun. 
 
The round body may grow 5 to 15 cm across with gently ridged sides. It is green to grayish brown and covered in tiny white dots that radiate down the ridges. The body has eight sections which are decorated with fine white hairs. In spring they often produce large yellow flowers with orange centers.