PT - JOURNAL ARTICLE AU - Van de Vijver, Bart AU - Schuster, Tanja M. AU - Williams, David M. AU - Kusber, Wolf-Henning TI - Revision of the genus Stauroforma (Staurosiraceae, Bacillariophyceae) based on varieties of Fragilaria virescens described by Albert Grunow DP - 2025 Sep 23 TA - Fottea AID - 10.5507/fot.2025.011 IS - 18025439 AB - A revision of the genus Stauroforma is proposed based on the analysis of several historic slides prepared by Grunow to describe Fragilaria virescens var. exigua. The original materials are analysed using both light and scanning electron microscopy together with a critical examination of the original drawings and notes Grunow made on his new taxa. Based on this, the genus description of Stauroforma is emended and the morphological descriptions of S. exiguiformis and S. inermis are updated. Grunow's variety subsalina is raised to species level as Stauroforma subsalina. A new species, Stauroforma subcassubica is described splitting it from S. cassubica, the latter having larger valves. The results of this revision will enable a more exact identification of the different Stauroforma species observed in freshwater and brackish water bodies in Europe.