Mammilloydia is a genus of cactus containing the sole species Mammilloydia candida, the snowball cactus. Description Mammilloydia candida is green, globe-shaped, but with age it becomes almost cylindrical. It can reach a diameter of about and a height of about . As is usual in the genus Mammillaria, this plant has no ribs. The flowers are pink or white. The plant is covered by fine white hair. The spines are short, very numerous, usually snow white or brown. Distribution This species originates from Mexico (Coahuila, Nuevo León, San Luis Potosí and Tamaulipas). Habitat The natural habitat of Mammilloydia candida is the desert. It grows in the thickets of xerophytic shrubs on calcareous soils, at an altitude of above sea level. References Cacti Guide Desert Tropical EoL Genus Mammilloydia in USDA Cactoideae genera Monotypic Cactaceae genera Cacti of Mexico