Carnegiea subg. Rooksbya Backeb. in Cact. Succ. J. (Los Angeles) 22(5): 154. 1950 Carnegiea subg. Rooksbya Backeb. in Cact. Succ. J. (Los Angeles) 22(5): 154. 1950Taxon for this nameCarnegiea subg. Rooksbya Backeb.