The Pinnularia genus in south-eastern Poland with consideration of rare and new taxa to Poland

In the studies conducted in 2007–2012 in south-eastern Poland, 56 diatom taxa were found from the Pinnularia genus. Pinnularia brebissonii (Kützing) Rabenhorst, P. obscura Krasske, P. viridiformis Krammer, P. lundii Hustedt, and P. viridis (Nitzsch) Ehrenberg occurred at most of the investigated sites. Eighteen taxa were considered as new to Polish flora. Some taxa are very rare in Poland and Europe and are found in only a few localities. Eight taxa are listed on the Polish Red List of Algae, including six taxa classified as endangered (E): P. nobilis (Ehrenberg) Ehrenberg, P. nodosa (Ehrenberg) W. Smith, P. subrupestris Hantzsch, P. schoenfelderii Krammer, P. subgibba Krammer and P. viridiformis Krammer.