Blechnaceae
Blechnaceae is a family of ferns in the order Polypodiales, with a cosmopolitan distribution. Its status as a family and the number of genera included have both varied considerably. In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), the family has 24 genera, and excludes genera placed in the separate family Onocleaceae. The family is divided into three subfamilies, including Blechnoideae s.s. Alternatively, the entire family may be treated as the subfamily Blechnoideae s.l. of a very broadly defined family Aspleniaceae, and include genera others place in Onocleaceae. Description Most are ground dwelling, some are climbers, such as Stenochlaena. A characteristic feature of many species is that the young opening fronds are usually tinged with red. Taxonomy The family was created by Newman in 1844. In 2014, Christenhusz and Chase submerged it as subfamily Blechnoideae within the family Aspleniaceae and included Onocleaceae in it. The PPG I classification of 2016 restored it to family status. Blechnaceae is a member of the eupolypods II clade (now the suborder Aspleniineae), in the order Polypodiales. It is related to other families in the clade as in the following cladogram: Subdivisions The number of genera accepted within Blechnaceae (or Blechnoideae when treated as