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Mammillaria formosa ssp formosa

First description by Galeotti, ex Scheidweiler, Bull. Acad. Sci. Brux. 5: 497 (1838)

Body: Plants solitary, sometimes clustering with age. Stems depressed globose to short cylindrical, light green, 15 - 20 cm (5.7 - 7.9 in) high, 9 - 10 cm (3.5 - 3.9 in) or more in diameter.

Roots:

Sap: Tubercules with latex.

Tubercule arrangement:

Tubercule: Crowded, pyramidal.

Axil: With white wool.

Radial spine: 20 - 22, sometimes absent, thin, needle- or bristle-like, sometimes flattened, white, 3 - 6 mm (to 0.2 in) long)

Central spine: 4 - 7, usually 6, pinkish with darker tips, to 8 mm (0.3 in) long.

Flower: Pale pink, 10 - 15 mm (0.4 - 0.6 in) in diameter.

Fruit: Red.

Seed: Light brown.

Flowering period in Cultivation (Europe):

Minimum temperature:

Habitat Substrate:

Geographic Distribution: Coahuila, Aguascalientes, Guanajuato, Zacatecas, Tamaulipas, Nuevo Leon and San Luis Potosi, Mexico. Altitude 960 - 2.350 m.

Comments: Given enough time, M. Formosa will form mounds. The heavier spined forms can be placed in very bright light, or perhaps in the dappled shade of a tree or shrub. Needs no special care, but an open gritty potting mix with some limestone may be beneficial. Subspecies Microthele should be grown conservatively to preserve the flat habit that is present in the wild.

Bibliography:
John Pilbeam (1999) - Mammillaria The Cactus File Handbook - page 102.
Edward F. Anderson (2001) - The Cactus Family - page 417.

Synonymes:
M. arroyensis