Origin and Habitat: Oaxaca (Mexico, Northern America). This species occurs in abundance in the Sierra Mixteca between [Santiago] Tejupan and [San Cristóbal] Suchixtlahuaca, but you can find some specimens near Acatepec too.

• Mammillaria casoi Bravo

• Mammillaria mystax Mart.
• Cactus mystax (Mart.) Kuntze
• Neomammillaria mystax (Mart.) Britton & Rose
• Mammillaria atroflorens Backeb.
• Mammillaria casoi Bravo
• Mammillaria crispiseta R.T.Craig
• Mammillaria erythra Repp.
• Mammillaria erythra f. ruber Repp., n.n.
• Mammillaria ruber Repp.
• Mammillaria mixtecensis Bravo
• Mammillaria mystax var. huajuapensis (Bravo) Lizen
• Mammillaria huajuapensis Bravo

Description: Mammillaria casoiSN|20654]]SN|20660]] (M. mixtecensis) is a local variant of the widespread, South Mexican Mammillaria mystaxSN|20654]]SN|20654]], from Oaxaca. The stems are simple up to 10 cm in diameter, with 5-7 radial and 3-4 central spines. The flowers are pinkish, numerous in rings around the shoulder of the plant. M. casoi is very variable in spination and is generally included within (as a synonym of) M. mystax, suggesting that there is not really a fundamental difference between the two, and hard to name accurately without knowing where they come from.
For more details see: SN'>20654' alt='20660'>Mammillaria mystax#SN#20654'> [[Mammillaria mystaxSN' style='border:none;'> |SN|20654]].

Bibliography: Major references and further lectures
1) Mammillaria casoi in: Cactus and Succulent Journal of Great Britain, Volume 44 Cactus and Succulent Society of Great Britain, 1982
2) Salvador Arias Montes, Susana Gama López, Leonardo Ulises Guzmán Cruz “Flora del Valle de Tehuacán-Cuicatlán” UNAM, 1997
3) Jorge Meyrán García “Botanical guide to the Valley of Tehuacán: covering especially the cacti and other succulents” Sociedad Mexicana de Cactología, 1980