The Athyriaceae (ladyferns and allies) are a family of terrestrial

fern The ferns (Polypodiopsida or Polypodiophyta) are a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. They differ from mosses by being vascular, i.e., having specialized tissue ...

s in the order

Polypodiales The Order (biology), 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 Tropics, tropical, semitropical and Temperate clima ...

. In the

Pteridophyte Phylogeny Group The Pteridophyte Phylogeny Group (PPG) is an informal international group of systematic botanists who collaborate to establish on the classification of pteridophytes ( lycophytes and ferns) that reflects knowledge about plant relationships discove ...

classification of 2016 (PPG I), the family is placed in the suborder

Aspleniineae Aspleniineae is a suborder of ferns in the order Polypodiales. It is equivalent to the clade eupolypods II in earlier systems; it is also treated as a single very broadly defined family Aspleniaceae. The suborder generally corresponds with the o ...

, and includes two genera. Alternatively, it may be treated as the subfamily Athyrioideae of a very broadly defined family

Aspleniaceae The Aspleniaceae (spleenworts) are a family of ferns, included in the order Polypodiales. The composition and classification of the family have been subject to considerable changes. In particular, there is a narrow circumscription, Aspleniaceae ...

. The family has a

cosmopolitan distribution In biogeography, a cosmopolitan distribution is the range of a taxon that extends across most or all of the surface of the Earth, in appropriate habitats; most cosmopolitan species are known to be highly adaptable to a range of climatic and en ...

Description

Species of the Athyriaceae are terrestrial or lithophytic, less commonly aquatic. They grow from various kinds of

rhizome In botany and dendrology, a rhizome ( ) is a modified subterranean plant stem that sends out roots and Shoot (botany), shoots from its Node (botany), nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from ...

: 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

, a status maintained by

Plants of the World Online Plants of the World Online (POWO) is an online taxonomic database published by the Royal Botanic Gardens, Kew. History Following the Convention on Biological Diversity, the Royal Botanic Gardens in Kew launched Plants of the World Online i ...

. The

PPG I The Pteridophyte Phylogeny Group (PPG) is an informal international group of systematic botanists who collaborate to establish on the classification of pteridophytes ( lycophytes and ferns) that reflects knowledge about plant relationships discove ...

classification of 2016 restored it to family status. Athyriaceae is a member of the eupolypods II clade (now the suborder Aspleniineae), in the order

. It is related to other families in the clade as in the following cladogram: The Athyriaceae in the past included '' Cystopteris'' and '' Gymnocarpium'' (now part of Dennstaedtiaceae). The family has been subsumed in the family

Woodsiaceae Woodsiaceae is a family of ferns. In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), it is placed in the suborder Aspleniineae. The family can also be treated as the subfamily Woodsioideae of a very broadly defined family A ...

, but a Woodsiaceae defined in this way may be

paraphyletic Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...

if it omits the Onocleaceae and Blechnaceae (as of 2006, the evidence was not clear).

Genera

As circumscribed in

, Athyriacae contains the following genera. *''

Athyrium ''Athyrium'' (lady-fern) is a genus of about 180 species of terrestrial ferns, with a cosmopolitan distribution. It is placed in the family Athyriaceae, in the order Polypodiales. Its genus name is from Greek '' a-'' ('without') and Latinized G ...

'' Roth (including ''Anisocampium'' and ''Cornopteris'' Nakai) *''

Deparia ''Deparia'' (or the false spleenworts) is a genus of ferns. The Pteridophyte Phylogeny Group classification of 2016 (PPG I) places the genus in the family Athyriaceae, although other sources include it within an expanded Aspleniaceae The Asple ...

'' Hook. & Grev. *''

Diplazium ''Diplazium'' is a genus of ferns that specifically includes the approximately 400 known species of twinsorus ferns. The Greek root is ''diplazein'' meaning ''double'': the indusia in this genus lie on both sides of the vein. These ferns were ...

'' Sw. , the ''Checklist of Ferns and Lycophytes of the World'' recognizes three further genera, which other sources include in ''Athyrium'': *''Anisocampium'' C.Presl *''Cornopteris'' Nakai *''Pseudathyrium'' Newman The genera have the following

phylogenetic In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical dat ...

relationships:

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 In forestry and ecology, understory (American English), or understorey (Commonwealth English), also known as underbrush or undergrowth, includes plant life growing beneath the forest canopy without penetrating it to any great extent, but above ...

below trees and shrubs.

References

{{Authority control Fern families