Contribution to the bryoflora of the Roztocze National Park (SE Poland) - Bryophytes of the Swierszcz river valley

New distribution data for 171 bryophyte taxa in the Roztocze National Park are provided. Among them there are 43 species protected by law in Poland, including 20 strictly protected species, as well as 13 species threatened in Poland. The research revealed 36 species (5 liverworts and 31 mosses) new for the region. Noteworthy is the occurrence of 19 mountain species and 10 bryophytes thought to be relicts of old-growth forests what confirms the specificity of nature of the Roztocze region. The most valuable and interesting finds are: mosses Campylophyllopsis sommerfeltii (Myrin) Ochyra, Dicranum viride (Sull. & Lesq.) Lindb., Buxbaumia viridis (Moug. ex Lam. & DC.) Brid. ex Moug. & Nestl. as well as liverworts Calypogeia suecica (Arnell et J. Perss.) Müll. Frib. and Cephalozia catenulata (Huebener) Lindb. A brief characterisations of these species are presented.