Origin and Habitat: Mammillaria vetulaSN|9161]]SN|9161]] is found in the Mexican states of Hidalgo, Guanajuato and Querétaro. This species is relatively abundant but not common. It occurs in colonies.
Altitude range: From 1,600 to 3,350 metres above sea level.
Habitat and ecology: The species is found is pine forests at high elevations. There are no major threats, however some subpopulations are affected by logging of pine forest and land-use change (mines). This cactus is grown as an ornamental. Some forms are very common in cultivation as propagated plants.

• Mammillaria vetula Mart.
• Cactus vetulus (Mart.) Kuntze
• Chilita vetula (Mart.) Orcutt
• Escobariopsis vetula (Mart.) Doweld
• Neomammillaria vetula (Mart.) Britton & Rose

• Mammillaria vetula Mart.
• Cactus vetulus (Mart.) Kuntze
• Chilita vetula (Mart.) Orcutt
• Escobariopsis vetula (Mart.) Doweld
• Neomammillaria vetula (Mart.) Britton & Rose
• Mammillaria kuentziana P.Fearn & B.Fearn
• Mammillaria vetula subs. lacostei Plein & Heinr.Weber
• Mammillaria vetula subs. magneticola (J.Meyran) U.Guzmán
• Mammillaria magneticola J.Meyran

• Mammillaria vetula subs. gracilis (Pfeiff.) D.R.Hunt
• Cactus gracilis Kuntze
• Escobariopsis gracilis (Pfeiff.) Doweld
• Krainzia gracilis (Pfeiff.) Doweld
• Mammillaria gracilis Pfeiff.
• Mammillaria gracilis var. fragilis (Salm-Dyck) A.Berger
• Chilita fragilis (Salm-Dyck) Orcutt
• Mammillaria fragilis Salm-Dyck
• Neomammillaria fragilis (Salm-Dyck) Britton & Rose
• Mammillaria gracilis var. pulchella Salm-Dyck
• Mammillaria gracilis f. pulchella (Salm-Dyck) Schelle

• Mammillaria vetula subs. gracilis cv. Arizona Snowcap
• Mammillaria gracilis f. monstruosa hort.
• Mammillaria gracilis cv. Arizona Snowcap
• Mammillaria gracilis cv. Buenavista
• Mammillaria gracilis cv. Regina
• Mammillaria vetula subs. gracilis cv. Clone A
• Mammillaria gracilis f. monstruosa (Clone A)

Description: Mammillaria vetulaSN|9161]]SN|9161]] is a small freely clustering cactus forming flat-topped mounds. Two subspecies are recognized, the nominate subspecies and subsp. gracilis (Pfeiff.) D.R.Hunt.
Stems: Globose to cylindrical, glossy blue-green, to 10 cm long and 4 cm in diameter, offsets numerous butmore firmly attached than in subsp. gracilis.
Tubercles: Main stem tubercles to 8 mm, firm to slightly flabby, bluntly conical, four-sided basally, without latex, axils slightly woolly or naked.
Central spines: Typically 1-2, (sometimes absent in subsp. gracilis), reddish brown, straight, stout, needle-like, to 10 mm long.
Radial spines: at least 25 at first, later as many as 50, (or only 11-16 in subsp. gracilis), white, thin, straight, needle-like, 3-10(-12) mm long.
Flowers: Pale yellow or lemon yellow, to 17 mm long.
Blooming season: Autumn.
Fruits: Whitish to greenish.
Seeds. Black.

Bibliography: Major references and further lectures.
1) Gómez-Hinostrosa, C., Sánchez , E., Guadalupe Martínez, J. & Bárcenas Luna, R. 2013. "Mammillaria vetula." The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>. Downloaded on 29 January 2015.
2) John Pilbeam “Mammillaria The Cactus File Handbook” Cirio Pub. Services, 01/December/1999
3) John Pilbeam “Cacti for the Connoisseur: A Guide for Growers & Collectors” Timber Press, 01 July 1987
4) Hans Hecht “Cacti & Succulents” Sterling Publishing Company Incorporated, 1994
5) Alfred Byrd Graf “Exotica, series 4 international: pictorial cyclopedia of exotic plants from tropical and near-tropic regions” Roehrs Co. Publishers, 1982
6) David Squire “Photographic Encyclopedia of Indoor Plants” Gallery Books, 1991
7) Edward Anderson “The Cactus family” Timber Press, Incorporated, 2001
8) 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/August /2011
9) David R Hunt; Nigel P Taylor; Graham Charles; International Cactaceae Systematics Group. "The New Cactus Lexicon" dh books, 2006
10) Urs Eggli, Leonard E. Newton: "Etymological Dictionary of Succulent Plant Names." Birkhäuser 2004
11) Ulises Guzmán, Salvador Arias, Patricia Dávila: "Catálogo de cactáceas mexicanas." Universidad Nacional Autónoma de México, Mexiko-Stadt 2003

Cultivation and Propagation: Readily Mammillaria vetulaSN|9161]]SN|9161]] forms many offsets from sides and top. It does best in a mineral soil, good drainage is essential. Water sparingly during the summer months and keep dry in winter. It is a slow growing plant and once established, it will be content in its position and with its soil for years. Extremely hardy, can tolerate full sun, long periods of dryness and light frost (-4° C). It can also grows in moderate shade, and a plant that has been growing in shade should be slowly hardened off before placing it in full sun as the plant will be severely scorched if moved too suddenly from shade into sun.
Propagation: It is propagated exclusively from cutting during spring or summer.