Gymnocactus viereckii (Werderm.) Backeb. in Cact. Succ. J. (Los Angeles) 23: 151. 1951
Gymnocactus viereckii in Cact. Succ. J. (Los Angeles) 23: 151. 1951
is new combination for Echinocactus viereckii in Monatsschr. Deutsch. Kakteen-Ges. 3: 175. 1931