Mammillaria
Species designations are mostly wild guesses.
I’m fairly confident assigning 20 or so specimens in my garden to the genus Mammillaria, but most of the species designations are VERY tentative.
Mammillaria boolii
Common Names include:
RUSSIAN (Русский): Маммиллярия Бола
UKRAINIAN (Українська): Мамілярія Буля
Mammillaria hahniana
Old Lady Cactus
Mammillaria gracilis fragilis
Thimble Cactus
Mammillaria bombycina
Silken Pincushion
Mammillaria columbiana
Species designation is VERY tentative
Mammillaria matudae
Species designation is VERY tentative. Click on image to open post.
Mammillaria elongata
Ladyfinger cactus
How many species?
Mammillaria is the cactus genus with the greatest number of species next to Opuntia. Hundreds of species have been described, although only about 170 of them represent good species.
The Encyclopedia of Cacti
These 250 or so sun-loving cacti…
The Complete Book of Cacti & Succulents
With nearly 200 recognized species, the genus Mammillaria is one of the largest of the cactus family…Currently 171 of 171 known species in this genus are represented on CactiGuide.com.