Like several of its close relatives (e.g. Fenestraria) and other plants in its ecotype (e.g. some species of Haworthia and Bulbine) it has leaf-windows as an adaptation to the difficulties of photosynthesis in its arid environment.
The garden contains about 170 species of carnivorous plants, one of the largest such collections in Germany, as well as good collections of Euphorbia (300 species), Mediterranean plants (250 species), Haworthia and Aloe (65 species), as well as Aeonium, Conophyllum (40 species), Rhipsalis, and rare plants from Socotra.