Publication: Bluh. Kakteen 5: under pl. 60. 1905
Description
Mammillaria carmenae is a solitary or clustering globular cactus.
Stems: Globose to ovoid, 4 - 10 cm high, 3 - 5 cm in diameter. Without latex.
Tubercles: Conical. Axil: Woolly and bristly.
Radial spines: More than 100, soft, fine, flexible, star-like, white or pale yellow (or gold), up to 5 mm long.
Central spines: There are no central spines.
Flowers: Diurnal, (usually) creamy white to pink or pale pink with pink tinged midribs, up to 11 mm long.
Blooming season (Europe): Plants blooms at the same time in late winter-early spring, and are very generous with their flowers.
Fruits: Greenish.
Seeds: Black.
Origin and Habitat
Between Ciudad Victoria and Iaumave, Tamaulipas (Mexico, Northern America)
It was originally found by Marcelino Castañeda in 1953 near the La Reja ranch, but it was soon lost in cultivation after its description until 1977, when it was rediscovered by Alfred Lau.
Habitat: Grows in crevices in north-facing rocks. Altitude 850 to 1.900 m. The Mammillaria carmenae is in danger of extinction in the wild.
Cultivation and Propagation
It is a relatively rapid growing species. This is easily grown into clumps, but it does often have an irregular pattern of offsetting. Water regularly in summer, but do not over-water (rot prone). Use a pot with good drainage and a very porous potting media. Keep dry in winter. Feed with a high potassium fertilizer in summer. It is quite frost resistant if kept dry, hardy as low as -5° C. Outside full sun or afternoon shade, inside it needs bright light, and some direct sun.
Easily clustering and easily flowered. Most plants will offset readily, and clumps can be produced in a few years.
Propagation: By division, or direct sow after last frost.