Mammillaria cactus, with over 200 species is the largest genus in the cactus family. Mammillaria are mostly native to Mexico and surrounding countries. With such a large number of species Mammillaria are a diverse group, generally low growing. Species include Mammillaria magnimamma, Mammillaria hahniana ( old lady cactus), Mammillaria multiceps and Mammillaria johnstoniiMammillaria do well in containers and require a well drained potting mix to grow well. Nurseries, Mail Order Nurseries, Specialist Nurseries,Retail Nurseries.