Neowerdermannia vorwerkii var. gielsdorfiana Backeb. in Cact. Succ. J. (Los Angeles) 23: 86. 1951 Neowerdermannia vorwerkii var. gielsdorfiana Backeb. in Cact. Succ. J. (Los Angeles) 23: 86. 1951Taxon for this nameNeowerdermannia vorwerkii var. gielsdorfiana Backeb.