수전옥(守殿玉) Gymnocalycium stellatum

  
                                            수전옥(守殿玉)                                           봉두(鳳頭) Gymnocalycium asterium

 
                                                      봉두(鳳頭) Gymnocalycium asterium

 
                                                       봉두(鳳頭) Gymnocalycium asterium

  
                   봉두(鳳頭)                                           용두(龍頭) Gymnocalycium quehlianum

 
                                               용두철화