Mammillaria chionocephala | Kakteen und sukkulenten, Kaktus blume, Kaktus
British Cactus and Succulent Society on Twitter: "Mammillaria chionocephala, a typically flowered species in this large genus of cacti. Some species have much larger flowers but they tend to be the more '
Mammillaria chionocephala - Agaveville
Mammillaria (Mammillaria formosa subsp. chionocephala 'Ritteriana') in the Mammillarias Database - Garden.org