^Assessor: Donaldson,J.S.; Evaluators: Vovides,A. & Chemnick,J. (Cycad Red List Authority) (2003). "Dioon purpusii in IUCN 2010". IUCN Red List of Threatened Species. Version 2010.1. International Union for Conservation of Nature and Natural Resources. Retrieved May 1, 2010.{{cite web}}: CS1 maint: multiple names: authors list (link)
^Plant description originally published in: Contr. U.S. Natl. Herb. 12(7): pp. 260-261 (1909). Note that this source is likely incorrect in showing someone named 'J.S. Rose' as a collector. The authority, Rose, is Joseph Nelson Rose (see next footnote) Ken Hill. "Dioon purpusii". The Cycad Pages. Royal Botanic Gardens, Sydney. Archived from the original on 19 July 2005. Retrieved May 2, 2010. TYPE: Mexico, Oaxaca, Tomellin Canyon, 7 Sep 1906, J.N.R. & J.S. Rose 11352 (holoUS, isoF, NY).