Athyriaceae


The Athyriaceae are a family of terrestrial ferns in the order Polypodiales. In the Pteridophyte Phylogeny Group classification of 2016, the family is placed in the suborder Aspleniineae, and includes two genera. Alternatively, it may be treated as the subfamily Athyrioideae of a very broadly defined family Aspleniaceae. The family has with a cosmopolitan distribution.

Description

Species of the Athyriaceae are terrestrial or lithophytic, less commonly aquatic. They grow from various kinds of rhizome: short or long, creeping or erect, branched or not. The distribution and evolution of characters in the family is complex, and the genera have few constant features by which they can be identified. The sporangia have stalks two or three cells wide in the middle, and contain brown monolete spores.

Taxonomy

Earlier classifications

The family was first created by Arthur H.G. Alston in 1956. It has had a varied history. In 2014, Christenhusz and Chase submerged it as the subfamily Athyrioideae within the family Aspleniaceae, a status maintained by Plants of the World Online as of 2019. The PPG I classification of 2016 restored it to family status.
Athyriaceae is a member of the eupolypods II clade, in the order Polypodiales. It is related to other families in the clade as in the following cladogram:
The Athyriaceae in the past included Cystopteris and Gymnocarpium. The family has been subsumed in the family Woodsiaceae, but a Woodsiaceae defined in this way may be paraphyletic if it omits the Onocleaceae and Blechnaceae.

Genera

As circumscribed in PPG I, Athyriacae contains the following genera.
, the Checklist of Ferns and Lycophytes of the World recognizes three further genera, which other sources include in Athyrium:
The genera have the following phylogenetic relationship:

Distribution and habitat

Athyriaceae has a worldwide distribution, particularly the genus Athyrium. Most species of Athyriaceae are medium-sized terrestrial ferns, growing in the understorey below trees and shrubs.