Polypodioideae

Polypodioideae is a subfamily belonging to the fern family Polypodiaceae, which is a member of the suborder Polypodiineae in the Pteridophyte Phylogeny Group classification of 2016 (PPG I). Alternatively, the subfamily may be treated as the tribe Polypodieae within a very broadly defined family Polypodiaceae sensu lato.

==Taxonomy== Two very different circumscriptions of the subfamily were in use . In the first, such as the Pteridophyte Phylogeny Group classification of 2016 (PPG I) used here, the subfamily Polypodioideae is one of a number of subfamilies of the family Polypodiaceae which is part of the suborder Polypodiineae. In the second, the whole of the suborder is placed in a very broadly defined Polypodiaceae sensu lato, in which the subfamily Polypodioideae sensu lato is equivalent to the family Polypodiaceae and the tribe Polypodieae to the subfamily Polypodioideae. The equivalence is shown in the following table. {| class="wikitable" |- ! PPG I !! Christenhusz & Chase (2014) |- |Suborder Polypodiineae Dumort.||Family Polypodiaceae J.Presl & C.Presl |- |- |style="padding-left: 2em;"|Family Polypodiaceae J.Presl & C.Presl||style="padding-left: 2em;"|Subfamily Polypodioideae B.K.Nayar |- |- |style="padding-left: 4em;"|Subfamily Polypodioideae J.Presl & C.Presl||style="padding-left: 4em;"|Tribe Polypodieae Hook. & Lindl. ex Duby |}