(This plant comes in a 3.5" pot. You will receive a very similar plant to the one in the picture. It may or may not be blooming at the time of your purchase. The plant is shipped in its pot to prevent any damage to the roots).
Mammillaria zeilmanniana is a dark green globular plant with red central spines and has clusters of white radial spines. Rings of reddish violet flowers are usually present. Theses are one of the most prolific bloomers of the Mammillarias.
Recommended temperature zone: Sunset: 13-24, 29, 30, USDA: 9-10
Frost tolerance: Hardy to 20°F (-6°C) if kept dry.
Minimum avg. temperature: 50°F (10°C)
Sun exposure: Light shade
Origin: Guanajuato state, central Mexico
Growth habits: Clumping, spherical, dark green cactus, up to 5" tall (12 cm), 3 inches wide (8 cm)
Watering needs: Regular water in summer
Blooming habits: The Mammillaria zeilmanniana is one of the most prolific bloomers among the Mammillarias. The white or red-violet flowers (depending on the clone) can come at any time most of the year.
Some of the information in this description has been found at desert-tropicals.com, llifle.com and cactus-art.biz