Die Identitat von Gomphonema entolejum Ostrup (Bacillariophyceae) sowie Revision ahnlicher Arten mit weiter Axialarea
This paper presents a revision of some Gomphonema taxa characterized by a wide axial area, short (marginal) striae composed of single rows of areolae and the presence of a stigma near the central nodule. Since the identity of the classical species G. brachyneurum, G. clevei, G. entolejum and G. frickei remained unknown, misinterpretations and incorrect species concepts have led to the wrong assumption that these species (may) belong to one taxon which was mainly called G. clevei. Accordingly, data on their distribution are misleading. With the exception of G. clevei the identity of the other classical taxa could be clarified with the help of type specimens or original material. They proved to be independent species with a more restricted distribution than suggested so far. The same applies to G. clevei var. javanica which was raised to species rank with the new name G. sundaense. In addition four species are described as new (G. hawaiiense, G. moresbyanum, G. pyrenaicum, G. siamense) and some other similar Gomphonemata are presented with additional data and/or micrographs.