Mammillaria albidula ( Backeberg )

First Description by Backeberg, Die Cactaceae 5 : 3429. 1961

Body: Globose to short cylindrical, solitary, 40 - 120 mm high and 40 - 100 mm in diameter, sunken apically, covered with wool.
Roots: Fibrous.
Sap: Without latex.
Tubercule: Closely set, firm, pyramidal, 5-6mm long and 3 mm thick, green to dull green.
Axil: With white wool.
Radial Spines: 10 - 14, needle-like, the sidemost the longest, pectinate, straight, horizontal radiating, glassy white, 2 - 6 mm long.
Central Spines: 0 - 1, often missing, 2-5 mm long, needle-like, straight, with thicker base, brown, at base lighter.
Flower: Funnel form, carmine pink, 16 – 18 mm long and 14 - 16 mm in diameter.
Fruit: Slender club-shaped, glossy red, 15 - 20 mm long and 3 - 4 mm thick. Ripens 6 months after flowering.
Seed: Brown, drop to kidney formed, 1mm long and 0,8 mm wide. Hilum whitish and subbasal. Selfsterile.
Minimum Temperature: 5 – 10 °C
Habitat Substrate: In rocky area in silicate, mineral ground between rocks and bushes.
Geographic Distribution: Colonia San Martin, Puebla, Mexico. Altitude 1600 - 2300 m.
Comments: The habitat is near these of Mammillaria conspicua, but in a small separate, limited area on the Westside of a mountain. Conspicua grows on the east side.
Bibliography: Reppenhagen, Die Gattung Mammillaria 1987.