Athyrium flexile

About

Athyrium flexile, commonly known as Newman's lady-fern or the flexile lady fern, is a taxon of fern which is endemic to Scotland. It has been regarded as a species, but it is considered to be an ecotype of the Alpine lady fern. This fern is pale to yellow green in colour and has elliptic, double pinnate leaves which are deciduous. This ecotype grows more quickly and matures faster than the Alpine lady fern in substrates which have low levels of nutrients and is outcompeted by the Alpine lady fern in other situations.

Summary from Wikipedia