Astrophytum myriostigma is a spineless cactus defined by the presence of three to seven (usually five) pronounced vertical ribs which define the cactus' shape when young . The genus name "astrophytum", literally, "star plant", is derived from the resulting star-like shape. As the cactus ages, more ribs may be added and it becomes more cylindrical in shape, growing up to about 70–100 cm tall and 10–20 cm in diameter. In the wild, globose to cylindrical stem is covered with a whitish flocking of trichomes. Some horticultural varieties lack the flocking.
Like most cacti they're drought tolerant and need very little care and attention to grow well. Not enough sunlight and over-watering are common mistakes.
Plenty of sunshine will keep this cacti more than happy. In a glass room you may have to provide some shade during a hot summers day to prevent sunburn
Feed every 4 weeks with a Nitrogen-poor and Potassium & Phosphorus-rich fertilizer during summer
It is an excellent plant for garden rockery settings, desert type landscapes, patios and botanical gardens