The studies were conducted on watercourses flowing out of raised peat bog areas in Orawsko-Nowotarska Basin and raised peat bogs and transitional moor in „Międzyrzeki” Reserve on the territory of the Roztocze National Park. New localities where Neidium hercynicum occurred were found on the peatland areas of Southern Poland (Orawsko-Nowotarska Basin) and South-eastern (the Roztocze National Park) during the studies conducted on Jamów, Tokarka and Chyżny streams and on the territory of “Międzyrzeki” Reserve between 2007–2013. Longer and wider specimens were found on both investigated sites in comparison to the dimensions listed in the Krammer and Lange-Bertalot key. N. hercynicum were always found as individual specimens.