Mammillaria surculosa Mammillaria tayloriorum Mammillaria tetrancistra – California pincushion Mammillaria theresae Mammillaria thornberi – clustered fishhook pincushion Mammillaria uncinata Mammillaria vetula Mammillaria voburnensis Mammillaria weingartiana Mammillaria wiesingeri Mammillaria winterae Mammillaria wrightii – brown pincushion Mammillaria wrightii ssp. wilcoxii – Wilcox's nipple cactus Mammillaria zeilmanniana Distribution and habitat Mammillarias is predominantly found in Mexico but also have a wide range of distribution in neighboring regions north of the equator including the southwest United States, the Caribbean, Guatemala and Honduras. The southernmost limits of its range appears to be Colombia, and Venezuela, where only two known species are found. Within this wide distribution, some species will exhibit large variations depending on the locality, sometimes even within just a few hundred feet. Some of these variations are so extreme that they have resulted in classifications of new species, many of which are so limited to one locality that they are considered critically endangered. Cultivation Mammillarias have extremely variable spination from species to species, and attractive flowers, making them attractive for cactus hobbyists. Most mammillarias are considered easy to cultivate, though some species are among the hardest cacti to grow. Several taxa are threatened with extinction at least in the wild, due to habitat destruction and especially overcollecting for the pot plant trade. Cactus fanciers can assist conservation of these rare plants by choosing nursery-bred specimens (wild-collected ones are illegal to possess for the rarest species). Several mammillarias are relatively easy (for cacti) to grow from seeds. One such species, popular and widely available from nursery stock but endangered in the wild, is Mammillaria zeilmanniana. Uses Water can be extracted from the cacti. References Further reading Butterworth, Charles A. & Wallace, Robert S. (2004): Phylogenetic studies of Mammillaria (Cactaceae) - insights from chloroplast sequence variation and hypothesis testing using the parametric bootstrap. Am. J. Bot. 91(7): 1086–1098. PDF fulltext Supplementary data External links cactiguide.com is the main source for the species list, and in turn sourced from several books which are listed on that site. mammillarias.net is the main up-to-date internet resource, with complete species and varieties description, distribution maps and a large selection of photographs of all Mammillaria species both in nature and cultivated. SucculentCity Mammillaria Page: Cultivation Data and Photographs Cactoideae genera