[3] It is related to other families in the clade as in the following cladogram:[4][3] Cystopteridaceae Rhachidosoraceae Diplaziopsidaceae Aspleniaceae Hemidictyaceae Thelypteridaceae Woodsiaceae Onocleaceae Blechnaceae Athyriaceae The number of genera accepted within Blechnaceae (or Blechnoideae when treated as a subfamily) has varied between authors.

However, the subclade sister to the rest of Blechnum sensu lato contains the vining taxa Stenochlaena, Salpichlaena J.Sm.

and a few non-vining Blechnum species with long-creeping rhizomes, which may have to be accepted at the generic level pending further studies.

They identified three major clades within the remaining Blechnaceae, which they labelled Woodwardia, super-Stenochlaena and super-Blechnum, with the latter two as sister groups.

Lorinseria Anchistea Woodwardia Salpichlaena Stenochlaena Telmatoblechnum Brainea Blechnidium Struthiopteris Spicantopsis Cleistoblechnum Blechnopsis Sadleria Lomaridium Lomaria Lomariocycas Icarus Cranfillia Blechnum Austroblechnum Diploblechnum Neoblechnum Doodia maxima Oceaniopteris Oceaniopteris species-group 2 Doodia Parablechnum In 2016, the Pteridophyte Phylogeny Group followed Gasper et al. (2016) in accepting 24 genera, grouped into three subfamilies with approximately 265 species, most of which are placed in the subfamily Blechnoideae.