Premise: Gymnocalycium fischeri is a globular cactus belonging to the family Cactaceae. The first description was in 2002 by Josef Halda Jacob, Petr Kupčák, Emil Lukasik and Jaromír Sladkovský. The specific epithet honors the Czech cactus collector Ladislav Fischer.
Hypothesis: Gymnocalycium is part of the family Cactaceae