The genus Mammillaria is one of the largest in the cactus family (Cactaceae), with currently 171 known species and varieties recognized. Most of the mammillarias are native to Mexico, but some come from the southwest USA, the Caribbean, Colombia, Venezuela, Guatemala and Honduras.
The common name "pincushion cactus" refers to this and the closely related genus Escobaria. The first species was described by Carolus Linnaeus as Cactus mammillaris in 1753, deriving its name from Latin mammilla, "nipple", referring to the tubercles that are among the distinctive features of the genus. In 1812, the cactus specialist Adrian Haworth described the genus Mammillaria to contain this and related species. Numerous species are commonly known as nipple cactus, fishhook cactus or pincushion though such terms may also be used for related taxa, particularly Escobaria.
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