The planktonic desmid species Staurastrum pseudoplanctonicum is described as new to science from Lake Garda in Italy and the Bautzen Reservoir in Germany. Besides providing a valid and legitimate name, we are publishing some SEM micrographs of its processes from the holotype in the Berlin herbarium. The new taxon is discussed with respect to the ongoing debate on species concepts in desmids and its relation to S. planctonicum and the S. manfeldtii/ pingue complex.