For more than 50 years, besides studying most of the genera in the Araceae, Josef Bogner also devoted much time to the genus Cryptocoryne, both field observations where he has seen more than 40 taxa in their natural habitats and in the cultivation of most of the species. He was an active member of informal groupings, and besides writing or co-authoring more than 40 papers on Cryptocoryne, he also promoted other people’s work, and has been involved in all together more than 100 articles on Cryptocoryne.