Leaf cacti with medium-sized, carmine red flowers in the summertime looks very familiar to us. They are very hardy ornamental plants that are easy to keep and thus they are widespread in old collections, at amateur cactus lowers and in offices. For a long time, these plants were known as Epiphyllum Ackermannii as a mistake. These hybrid plants were mentioned first by Charles McIntosh in 1829. Pfeiffer (1837) mentioned 18, whereas Britton and Rose (1924) more than 50 varieties of Cereus (Disocactus) speciosus, all of these varieties were most probably plant of hybrid origin and crosses between D. phyllanthoides and D. speciosus. Thge taxonomical status of Disocactus × hybridus was clarified by Heath in 1989. He mentioned them as Heliocereus × Nopalxochia hybrids. As in a conservative view, the cultivar name 'Ackermannii' is widespread among all carmine red, medium or small flowering plants that have mostly triangular stems. Nevertheless, uncertainties in its description indicate that this description does not belong to one single clone. In Hungary, these red flowered ornamental plants are popular, that are very similar to each other for the first look, and, thus, one may think them a little boring. But as a more careful observation, we can find significant differences between the different clones.