Mammillaria candida: This cactus popularly called 'Snowball' is a choice, attractive succulent plant with a so dense snowy white, spination, that its body appears almost hidden by spines. They are clearly related to the genus Mammillaria, but their unique seed structure and other anomalies indicates that their overall resemblance to Mammillaria is due to convergence and are usually recognized as segregate genera. However their true relationship remains unclear. So far: Mammilloydia candida subs. ortizrubiona, connected through the particularly lovely Mammilloydia candida var. rosea, representt the segregate genus Mammilloydia. It is native to Mexico, in particular to the states of San Luis Potosí, Coahuila, Tamaulipas and Nuevo Leon.