- ↑ database, NODC Taxonomic Code, 1996
- ↑ Checklist of CITES Species Part 1 CITES species index, 2011
- ↑ database, The PLANTS Database, 2000
- ↑ database, The PLANTS Database, 1996
- ↑ Hunt, David, 2006 The New Cactus Lexicon: Text
- ↑ U. S. Fish and Wildlife Service, 1993Endangered and Threatened Wildlife and Plants; Review of Plant Taxa for Listing as Endangered or Threatened Species Federal Register, vol. 58, no. 188
- ↑ 7.0 7.1 Roskov Y., Kunze T., Orrell T., Abucay L., Paglinawan L., Culham A., Bailly N., Kirk P., Bourgoin T., Baillargeon G., Decock W., De Wever A., Didžiulis V. (ed) (2014). "Species 2000 & ITIS Catalogue of Life: 2014 Annual Checklist". Catalogue of Life. Species 2000: Reading, UK. Ginkuhà 26 Mayo 2014.CS1 maint: multiple names: authors list (link) CS1 maint: extra text: authors list (link)
- ↑ (Canada);http://siit.conabio.gob.mx (Mexico) ITIS Global: The Integrated Taxonomic Information System
