In Górzno-Lidzbark Landscape Park (GLPK), 396 vascular plant species (~41% of GLPK’s 965 vascular plant species) were recorded in 2002–2004 in a study of a ~4.5 km forested section along the railway track between Gutowo Pomorskie and Klonowo: 201 species in forest margins and scrubland, 256 species in firebreaks, 331 species on embankments, and 217 species on trackway. One species is under strict protection, nine under partial protection. Of the recorded species, Cimicifuga europaea, Epipactis atrorubens, Hierochloë australis and Melittis melisophyllum are disappearing from the GLPK forests. Six species are considered rare or endangered in Poland and eight are redlisted for the Kujawsko-Pomorskie region. We also recorded 30 archeophyte species, three ergasiophytes, and 16 confirmed or probable kenophytes. The recorded alien species do not pose a threat to the biodiversity of the GLPK forests. Several species (Hieracium cymosum, Lathyrus tuberosus, Neslia paniculata, Picris hieracioides, Reseda lutea, Vitis vinifera) have not been recorded elsewhere in GLPK. Our observations and those of other researchers indicate the potential importance of the railway in maintaining local biodiversity.