Weingartia ambigua (Hildm. ex K.Schum.) Backeb. in Cact. Succ. J. (Los Angeles) 23: 86. 1951 Weingartia ambigua (Hildm. ex K.Schum.) Backeb. in Cact. Succ. J. (Los Angeles) 23: 86. 1951is new combination for Echinocactus ambiguus Hildm. ex K.Schum., Gesamtbeschr. Kakt.: 311. 1897–1899Taxon for this nameWeingartia ambigua (Hildm. ex K.Schum.) Backeb.