On February 21, 2022 Prof. Dr. Klaus Raschke, Emeritus of the Georg-August-University of Göttingen in Göttingen passed away. The German Botanical Society remembers Klaus Raschke as a pioneering plant physiologist. His main research interest was the question of how CO2 uptake and H2O release through the stomata of the leaves are adapted to environmental conditions. He succeeded in identifying the biochemical-biophysical processes underlying the opening and closing of the stomata and in characterizing important regulatory parameters. The work of Klaus Raschke and his colleagues made an important contribution to the development of climate models.