Open Access

Jan-Peter Frahm, Sonja Risse, Beatrice van Saan-Klein

• Germinating tests with bryophytes were undertaken with three moss species and two hepatic species. For the first time these tests were performed with aquaceous extracts of bryophytes in contrast to previous studies in which seeds were directly placed on moist bryophytes. First tests showed an inhibition of the germination rate in 3 species but an increase of the germination in one species. A second study revealed that aquaceous as well as alcoholic extracts in high concentrations inhibited the growth of cress, highly diluted extracts promoted the growth. Other authors found either only germination promoting effects or both, promoting and inhibiting effects. Experiments with compounds extracted from bryophytes cited in the literature had only growth inhibiting effects. Brachythecium rutabulum revealed growth inhibiting effects in a previous but growth promoting effects in this study. The conflicting results are hard to explain and should stimulate further more detailed studies. They maybe due to various combinations of different concentrations of bryophyte extracts, different bryophyte species, different pH and different seeds but also contamination by dust, soil, bacteria and fungi .