[2] It is the only genus in the family Rhachidosoraceae in the Pteridophyte Phylogeny Group classification of 2016 (PPG I).

[3] Alternatively, the genus may be placed in the subfamily Rhachidosoroideae of a more broadly defined family Aspleniaceae,[1] the family placement used in Plants of the World Online as of November 2019[update].

[4] The genus was described by Ren Chang Ching in 1964, with about 7 species in eastern and southeastern Asia, including Japan, the Philippines, and Sumatra.

[5] As of November 2019[update], Plants of the World Online accepted the following species:[4] The following diagram for the eupolypods II, based on Lehtonen, 2011,[6] and Rothfels & al., 2012,[7] shows a likely phylogenic relationship between the Rhachidosoraceae and the other families of the eupolypods II clade.

Cystopteridaceae Rhachidosoraceae Diplaziopsidaceae Aspleniaceae Hemidictyaceae Thelypteridaceae Woodsiaceae Onocleaceae Blechnaceae Athyriaceae