Polypodiineae is a suborder of

fern A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes exce ...

s in the order

Polypodiales The order Polypodiales encompasses the major lineages of polypod ferns, which comprise more than 80% of today's fern species. They are found in many parts of the world including tropical, semitropical and temperate areas. Description Polypodiale ...

. It is equivalent to the

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English ter ...

eupolypods I in earlier systems, and to the very broadly defined family Polypodiaceae in the classification of Christenhusz & Chase (2014). It probably diverged from the suborder Aspleniineae (eupolypods II) during the mid-Cretaceous. The divergence is supported by both molecular data and an often overlooked morphological characteristic which lies in the vasculature of the petiole. Most species that make up the suborder have three vascular bundles. The only exceptions are the grammitid ferns which have one, and the genus '' Hypodematium'' which has two. This differs from eupolypods II which mostly have two vascular bundles (except the well-nested blechnoid ferns which generally have at least three).

Taxonomy

In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), the group is treated as the suborder Polypodiineae, and divided into 11 families. Alternatively, it may be treated as a single, very broadly circumscribed family Polypodiaceae ''

sensu lato ''Sensu'' is a Latin word meaning "in the sense of". It is used in a number of fields including biology, geology, linguistics, semiotics, and law. Commonly it refers to how strictly or loosely an expression is used in describing any particular c ...

'', which is then divided into subfamilies. The relationship between the two approaches is shown in the table below.

Phylogeny

The Polypodiineae is one of two major groups of eupolypod families, treated as suborders, within the order

. In 2016, the Pteridophyte Phylogeny Group published a consensus

cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to ...

, based on "numerous phylogenetic studies" between 2001 and 2015. The location of the Polypodiineae within the order Polypodiales in this cladogram is: To the level of families, the subtree for the Polypodiineae is: Of the 108 genera in the suborder, 91 (84%) are placed in two families, Dryopteridaceae and Polypodiaceae.

References

{{Taxonbar, from1=Q30110526, from2=Q5410882 Polypodiales