Origin and Habitat: Mexico Southwest (Oaxaca Tomellin Canyon, Tecomavaca). Altitude 450 - 500 m.

• Mammillaria huitzilopochtli subs. niduliformis (A.B.Lau) Pilbeam
• Mammillaria huitzilopochtli var. niduliformis A.B.Lau

• Mammillaria huitzilopochtli subs. niduliformis (A.B.Lau) Pilbeam
• Mammillaria huitzilopochtli var. niduliformis A.B.Lau

Description: Mammillaria huitzilopochtliSN|15536]]SN|15536]] subs. niduliformis is a small cactus species, solitary or slowly clumping in untidy clumps.
Stems: At first spherical, later cylindric, 8 cm high, 6 cm in diameter, slightly depressed. Axil with dense white wool in the flowering area.
Radial spines: About 22, glassy whie, brown at base, 1.5 mm long.
Central spines:2 (occasionally up to 4), brown or black, 2 cm long, curving, one up one down, the lower slightly longer, flexible, thicker at the base.
Flowers: Bright pink to carmine, 15 mm long, 10 mm wide. Stigmas carmine.
Fruits: Red.
Blooming season: Winter (from November to March)
Seeds: Brown, very small.

Bibliography: Major references and further lectures.
1) Robert T. Craig “The Mammillaria handbook: with descriptions, illustrations, and key to the species of the genus Mammillaria of the Cactaceae” E P Publishing, 1945
2) John Pilbeam “Mammillaria The Cactus File Handbook” Cirio Pub. Services, 01/Dec/1999
3) Edward Anderson “The Cactus family” Timber Press, Incorporated, 2001
4) James Cullen, Sabina G. Knees, H. Suzanne Cubey "The European Garden Flora Flowering Plants: A Manual for the Identification of Plants Cultivated in Europe, Both Out-of-Doors and Under Glass" Cambridge University Press, 11/Aug/2011
5) David R Hunt; Nigel P Taylor; Graham Charles; International Cactaceae Systematics Group. "The New Cactus Lexicon" dh books, 2006
6) Arias, S., Valverde, T. & Zavala-Hurtado, A. 2013. Mammillaria huitzilopochtli. In: IUCN 2013. "IUCN Red List of Threatened Species." Version 2013.2. <www.iucnredlist.org>. Downloaded on 07 March 2014.

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 overwater (Rot prone) Use 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 needs bright light, and some direct sun.
Easily flowering. Most plants will offset readily, and clumps can be produced in a few years.
Propagation: Division, direct sow after last frost.