Gymnocalycium kieslingii f. castaneum O.Ferrari in Cact. Succ. J. (Los Angeles) 57: 246. 1985
Gymnocalycium kieslingii f. castaneum in Cact. Succ. J. (Los Angeles) 57: 246. 1985
is basionym for Gymnocalycium kieslingii subsp. castaneum in Kaktusy (Brno) 48: 55. 2012