When analyzing endangered plant species and developing population-orientated conservation strategies, information on distribution, status of populations (e.g., declining or stable) and biological risk (like poor reproduction, stenotopic behaviour) is required. We report on such a database assembled for a group of endangered and/or rare German pteridophyte species. A total of 20 species was investigated between 1992 and 1996 by completely evaluating all extant populations. Using these results, the species were arranged in 5 groups depending on number and size as well as on status of populations.

Key words: endangered pteridophytes, Germany