Species of the genus Diphasiastrum (Lycopodiaceae) represent a very problematic group of European flora. Their taxonomy is complicated by hybridization (incl. introgression) in particular.
Morphology, biosystematic characteristics, ecology, causes of endangerment and subsequent protection are phenomena described in this article. Secondary habitats are frequently favourable for most of the taxa in Central Europe.
For this reason nature conservation institutions should focus on such biotopes.