Children (4 direct children, 4 direct and indirect children):
Gymnocalycium megatae matoense
Gymnocalycium megatae subsp. matoense
Gymnocalycium megatae megatae
Gymnocalycium megatae subsp. megatae
Gymnocalycium megatae var. che-guevarae
Gymnocalycium megatae subsp. zecheri