In memorial Kees den Boer In 1984, Kees den Boer as a biology student at the University of Amsterdam performed a master study on the distribution and ecology of desmids in a Norwegian nature reserve ( At that time he suffered already from a first stage of multiple sclerosis problemizing a career as an active phycologist. Partly in compensation of that, he established the website and despite a progressive course of his disease he succeeded to support it until shortly before his death, last December. In recognition of his merits in this field two newly described desmid species were named after him, viz. Cosmarium denboeri (Meesters & Coesel, 2007) and Micrasterias denboeri (Coesel & Van Geest, 2014).The Dutch working group of desmids will remember Kees as a most involved, competent and engaging participant.