Abstract
The funarioid moss species Physcomitrium eurystomum, which is threatened with extinction, was the subject of this study. The riparian habitat type of this species is often under the influence of contaminated water, and, therefore, we tested the influence of selected potentially toxic elements (PTEs), namely zinc and copper, on the development, physiological features, and survival of the species on two different accessions (German and Croatian). The results obtained showed the different resilience of the two accessions to the PTEs. Flow cytometry analyses revealed that the two accessions differ significantly in terms of genome size. However, the different amplitude of resilience to the tested PTEs, the divergence in physiological responses, and survival within two accessions of the same species are confirmed, as well as the dissimilarity of their genome size, likely associated with ploidy level difference and possibly distinct hybrid origin.