Mammillarias.net

Mammillaria duoformis

First description by Craig & Dawson, Allan Hancock Foundation Occ. Papers 1-2:59 with plate (1948)

Body: Plants usually forming clumps. Stems cylindrical, to 9 cm (3.5 in) high, 3 - 4 cm (1.2 - 1.6 in) in diameter.

Roots:

Sap: Tubercules without latex, but latex present in the stem.

Tubercule arrangement:

Tubercule:

Axil: With bristles.

Radial spine: 18 - 20, slender, needle-like, straight, chalky white to pale yellow above, orange brown below, 5 - 7 mm (0.2 - 0.3 in) long.

Central spine: 4, pinkish tan below, blackish brown above, 10 - 12 mm (0.4 - 0.5 in) long, lowermost one hooked and longer.

Flower: Bright crimson, to 15 mm (0.6 in) long and 12 mm (0.5 in) in diameter.

Fruit: Pale brownish pink.

Seed: Brown.

Flowering period in Cultivation (Europe):

Minimum temperature: -4? C. ('claviformis' : 0? C.)

Habitat Substrate:

Geographic Distribution: Puebla, Oaxacana and Morelos, Mexico. Altitude 1.000 - 2.400 m.

Comments: Easy to grow, but care must be taken to avoid sun scorch. Some forms can be fast growers, while others are average in speed. All will form large clumps with time.

Bibliography:
John Pilbeam (1999) - Mammillaria The Cactus File Handbook - page 93.
Edward F. Anderson (2001) - The Cactus Family - page 415

Synonymes:
M. claviformis
M. duoformis var rectiformis
M. duaformis var xuchiapensis
M. erythrocalix
M. hamata (?)
M. heeriana
M. rossiana