The random amplified polymorphic DNA (RAPD) technique was used to study the genomic relationships of three liverworts from the genus Pellia: P.epiphylla, P. borealis and P. neesiana. Altogether 150 characters (150 DNA fragments obtained using PCR) were scored. These characters were used to create a matrix of pairwise distances between all the pairs of taxa. Both distance (UPGMA, Fitch-Margoliash and Neighbor-Joining) and binary character-state (Wagner and Camin-Sokal parsimony and compatibility) methods were applied for trees' construction. Our results strongly support distinction of the recently discovered sibling species of P.epiphylla - species N and P.epiphylla - species S, which have an allopatric distribution in Poland (N - North, S - South Poland). Moreover, our data also supports the hypothesis of a hybrid origin (alloploid) of the polyploid P. borealis from P. epiphylla-NxP.epiphylla-S. P.neesiana was excluded as a donor of either of the genomes of P. borealis.