Neolloydia knuthiana var. ysabelae (Schlange) A.T.Powell in Cact. Succ. J. (Los Angeles) 13(4): 154. 1995
Neolloydia knuthiana var. ysabelae in Cact. Succ. J. (Los Angeles) 13(4): 154. 1995
is new combination for Thelocactus ysabelae in Cact. Succ. J. (Los Angeles) 5: 551. 1934