Mammillaria bocasana. (Powder Puff Cactus). Sunset: 13-24, 29, 30; USDA: 8-10. Full sun to light shade. Hardy to 28 F. Regular water during growing season, keep dry during winter. Clumping, globular cactus with hairy spines, 2.5" in diameter. Pink or yellow flowers spring and summer. Origin: Central Mexico. 

Mammillaria bombycina.

Mammillaria boolii

Mammillaria brandegei.  70 km. W. Santa Rosalia/Baja Californa Norte, Mexico

Mammillaria bravoae.

Mammillaria calvescens

Mammillaria candida

Mammillaria capensis v. pallida.

Mammillaria celsiana

Mammillaria centralifera.

Mammillaria centricirrha. 

Mammillaria cirrhifera.

Mammillaria cladivae