[2] The group was previously synonymized with Mammillaria, until molecular phylogenetic studies determined that—when broadly circumscribed—Mammillaria is not monophyletic; thus, Cochemiea has been accepted as a distinct genus.

[4] The reasons for this are varied, ranging from climate change and habitat loss, in some regions, to the illegal harvesting (poaching) of wild cacti for personal collections or sale on the black market, or blatantly sold, as-is, fresh from the wild.

As these plants are naturally slow growers, wild cactus growth and reproduction rates may not meet the rate at which certain populations of species are being poached, thus creating gaps in the wild populations and risking complete regional depletion or extinction.

In 2021, Breslin, Wojciechowski and Majure placed the following species in the genus, some already placed there and some moved from Mammillaria, Neolloydia, Neomammillaria and Ortegocactus.

[3] As of December 2022[update], Plants of the World Online accepted in the genus the species moved by Breslin et al.[2]