|Scientific Name:||Mammillaria schwarzii|
|Taxonomic Notes:||Accepted as a valid species by Anderson (2001), Hunt (1999) and Pilbeam (1999).|
|Red List Category & Criteria:||Critically Endangered B1ab(iv,v)c(iv) ver 3.1|
|Assessor(s):||Sánchez , E., Fitz Maurice, W.A., Fitz Maurice, B & Bárcenas Luna, R.|
|Reviewer(s):||Superina, M. & Goettsch, B.K.|
Mammillaria schwarzii is considered Critically Endangered due to a very restricted range (extent of occurrence less than 100km2), it is only found in one location, and there is a continuing decline in the number of subpopulations and mature individuals due to extensive overcollecting, and there are extreme fluctuations in the number of mature individuals. In terms of cactus, this species has among the highest rates of natural population fluctuation, which makes it susceptible to rapid declines.
|Range Description:||The species is endemic to Guanajuato, Mexico. It grows near San Felipe on a steep volcanic rock face about 100 m (plan view) by 4 km long. The extent of occurrence is less than 100 km2. It grows at altitudes between 2,150 and 2,400 m asl.|
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Current estimated population size is less than 1,000 individuals.|
|Habitat and Ecology:||This cactus grows on steep volcanic rock (igneous) in semi-desert (matorral) and oak forest.|
|Use and Trade:||This cactus is collected in the wild to be used as an ornamental, which represents an important threat to the species.|
|Major Threat(s):||This species is highly threatened by illegal collecting. The locality is a standard stop for cactus tour groups from Europe and is now well-known to both commercial and amateur collectors.|
The species is listed on CITES Appendix II, but enforcement of the law in countries of destination is needed. This species has been widely propagated worldwide for 40 years. There is a strong need for site level protection to prevent collectors from removing individuals from the wild. In addition there is a strong need to monitor levels of population decline due to illegal harvesting.
This species is legally protected in Mexico by the national list of species at risk of extinction, NOM-059-SEMARNAT-2010, where it is listed under category “subject to special protection” (Pr; SEMARNAT 2010).
Anderson, E.F. 2001. The Cactus Family. Timber Press, Portland.
Fitz Maurice, W.A. 1988. Fieldnotes: The rediscovery of Mammillari schwarzii. Cactus and Succulent Journal (US) 60(2): ?
Fitz Maurice, W.A. and B. 1994a. Mammillaria schwarzii revisited. Cactus and Succulent Journal (US) 66(3): ?
Fitz Maurice, W.A. and B. 1994b. Der Fall Mammillaria schwarzii. Schumannia 1: 36-38.
Hunt, D. 1999. CITES Cactaceae Checklist, 2nd ed. Royal Botanic Gardens, Kew and International Organization for Succulent Plant Study (IOS).
IUCN. 2013. IUCN Red List of Threatened Species (ver. 2013.1). Available at: http://www.iucnredlist.org. (Accessed: 12 June 2013).
Pilbeam, J. 1999. Mammillaria. Cirio Publishing Services, Southampton.
SEMARNAT. 2010. Norma Oficial Mexicana NOM-059-SEMARNAT-2010, Protección ambiental-Especies nativas de México de flora y fauna silvestres-Categorías de riesgo y especificaciones para su inclusión, exclusión o cambio-Lista de especies en riesgo. Diario Oficial de la Federación.
Shurly, E. 1949. Mammillaria schwarzii. Cactus and Succulent Journal of Great Britain 11: 17.
|Citation:||Sánchez , E., Fitz Maurice, W.A., Fitz Maurice, B & Bárcenas Luna, R. 2013. Mammillaria schwarzii. The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>. Downloaded on 27 April 2015.|
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