Coryphantha pycnacantha is a cactus species endemic to central Mexico.
It is native to the states of Hidalgo, Puebla, Tlaxcala, and Veracruz
It grows on deep lava soils, and is an IUCN Red List Endangered species.
References
External links IUCN Red List report on Pediocactus sileri (Siler's Pincushion Cactus)