The identity of Eunotia paludosa Grunow 1862 (Eunotiaceae, Bacillariophyta), a revision, and the description of three new species of Eunotia Ehrenberg

Eunotia paludosa is an abundant and frequent diatom species in ombrotrophic, Sphagnum-dominated bog ponds in Europe. Analysis of the type material from Mandling, Austria, revealed that our currently accepted concept of E. paludosa, based on morphology, was incorrect. The valves in the type population of E. paludosa possess distinct, relatively large, acute spines on the dorsal margin, which are not present in what is currently understood under E. paludosa. Based on the comparison with the E. paludosa type material, three new Eunotia species are described. Eunotia sphagnicola encompasses all European populations formerly and thus incorrectly identified as E. paludosa. The former E. paludosa populations in the sub-Antarctic region are described as E. insularum, a widespread species on almost all sub-Antarctic islands. Finally, E. zackenbergensis was described from Greenland. The three new species differ from each other in valve dimensions, valve outline and shape of the apices.