Astrophytum myriostigma v columnare Live Cactus In 4 InchAstrophytum myriostigma v. columnare is a cactus native to Mexico. It can grow to be up to three feet tall and three inches wide. Astrophytums need very well draining soil. We recommend 80 90% grit depending on environment. These cactus also do not do well in cold environments. They are winter dormant and require little if any water during dormancy. Astrophytum myriostigma blooms yellow and white flowers an inch across. This is for one plant growing