About Cystopteris alpina (Lam.) Desv.
Cystopteris alpina (Lam.) Desv. is a fern species that belongs to the family Cystopteridaceae. This species is closely related to Cystopteris fragilis, and many authors have previously classified it as the same species as C. fragilis. According to the Flora of North America, C. alpina is an allopolyploid species that originated from hybridization, with Cystopteris montana identified as one likely parent species. It has been recorded hybridizing with C. fragilis in Scandinavia, and intermediate plants possibly of hybrid origin have been found in North Wales. C. alpina is a montane fern species distributed across most of Europe, with populations extending into Russia and mountainous regions of West Asia. It is widely found across Northern Scandinavia, the Alps, and the Pyrenees. In Britain, the species is thought to be extinct; it was only ever known from a single locality in Upper Teesdale, where it was last recorded in 1911. Ecologically, Cystopteris alpina is restricted to limestone in damp locations, and occurs mainly in upland areas.
