Correll, D. S. and M. C. Johnston, 1970. Manual of the vascular plants of Texas, Texas Research Foundation, Renner, Texas. p. 1678. 

Mahler, F. W. Rediscovery of Hymenoxys texana and notes on two other Texas Endemics. SIDA: 10, p.87-91, 1983.

Texas A&M Bioinformatics Working Group: http://www.csdl.tamu.edu/FLORA/cgi/endemics_map_page2?gen=Hymenoxys&spec=texana 

Texas Parks & Wildlife: http://www.tpwd.state.tx.us/nature/endang/txprdawn.htm

U.S. Fish and Wildlife Service: http://www.fws.gov/r9endspp/plants4.html