(Photograph: Mammillaria albata, Amante Darmanin)
Hundreds of species have been described for the genus, Mammillaria. Today, about 170 are accepted by botanists (Anderson, 2001). The genus is very popular, in part because many of the species are easy to grow and the plants are small enough for pot or windowsill growth.
The word “Mammillaria” was first used to describe this genus about 200 years ago. The name refers to the nipple-like areoles on many members of the genus (mammilla = nipple or teat in Latin). Five subgenera are recognized by many botanists. Native Americans ate the fruits from one or more species of Mammillaria.
M. geminispina was originally described in the 1820s by Augustin Pyramus de Candolle. Over 150 years later (1987), another botanist (Werner Reppenhagen) decided that the name should be M. albata. It may have even (once) been described as M. elegans. But, what ever you call it, it is an interesting plant and worth growing.
Additional Reading: Mammillaria