Argyrochosma stuebeliana

Argyrochosma stuebeliana is a fern endemic to Peru. Its highly divided, leathery leaves are coated with white powder on their under surface. It was originally described as a variety of Argyrochosma dealbata (then in Pellaea) in 1909, based on a single leaf collected by Alphons Stübel, whom its name honors. In 1961, it was recognized as a distinct species, distinguished from similar members of the genus largely by its round leaf segments. It was transferred to the new genus Argyrochosma in 1987....read more on Wikipedia.