New European locality of three rare taxa (Zygnematophyceae, Streptophyta): Cosmarium pseudoprotuberans var. sulcatum (Nordstedt) Coesel, Gonatozygon aculeatum W.N.Hastings and Pleurotaenium simplicissimum Grönblad

In the current article the new Ukrainian desmid material: three species new for Ukraine and their location are examined. The discussion focuses on comparing newly found species in Ukraine to their previous published descriptions in Europe. The reported distribution of these taxa in Europe: Cosmarium pseudoprotuberans var. sulcatum (Nordstedt) Coesel was reported for five countries, Gonatozygon aculeatum W.N.Hastings was found in eight countries and Pleurotaenium simplicissimum Grönblad was previously revealed only in four European countries. We provide a detailed description of the morphological characters of the Ukrainian cells and supply it with the drawings and pictures. The ecological aspects of the new habitat important for the European flora of desmids are discussed. This article provides information for better understanding of desmids ecology and correct identification of the described rare and sometimes poorly known species.