Aspleniaceae
Encyclopedia
The Aspleniaceae is a family of fern
s, included in the order Polypodiales
or in some classifications as the only family in the order Aspleniales.
Members of the family all have intramarginal, linear sori
with a flap-like indusium arising along one edge. Most pteridologists today consider this family of consisting of just one to three genera. Others still maintain segregate genera such as Phyllitis and Ceterach; however, the species segregated into these genera all hybridize readily with undisputed Asplenium species. A recent phylogenenetic study of Aspleniaceae (Murukami et al. 1999) shows that species segregated as Camptosorus and Neottopteris are nested within Asplenium and recommends that they be included in that genus, but suggests that Hymenasplenium (including Boniniella) and Phyllitis are distantly related to other Asplenium species and should be recognized at the generic level.
The genus Diellia, consisting of six species found only in Hawaii, was long considered to be independent, but now has been shown to nest within Asplenium.
Genera
Fern
A fern is any one of a group of about 12,000 species of plants belonging to the botanical group known as Pteridophyta. Unlike mosses, they have xylem and phloem . They have stems, leaves, and roots like other vascular plants...
s, included in the order Polypodiales
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...
or in some classifications as the only family in the order Aspleniales.
Members of the family all have intramarginal, linear sori
Sorus
A sorus is a cluster of sporangia .In fungi and lichens, the sorus is surrounded by an external layer. In some red algae it may take the form of a depression into the thallus....
with a flap-like indusium arising along one edge. Most pteridologists today consider this family of consisting of just one to three genera. Others still maintain segregate genera such as Phyllitis and Ceterach; however, the species segregated into these genera all hybridize readily with undisputed Asplenium species. A recent phylogenenetic study of Aspleniaceae (Murukami et al. 1999) shows that species segregated as Camptosorus and Neottopteris are nested within Asplenium and recommends that they be included in that genus, but suggests that Hymenasplenium (including Boniniella) and Phyllitis are distantly related to other Asplenium species and should be recognized at the generic level.
The genus Diellia, consisting of six species found only in Hawaii, was long considered to be independent, but now has been shown to nest within Asplenium.
Genera
- AspleniumAspleniumAsplenium is a genus of about 700 species of ferns, often treated as the only genus in the family Aspleniaceae, though other authors consider Hymenasplenium separate, based on molecular phylogenetic analysis of DNA sequences, a different chromosome count, and structural differences in the rhizomes...
- Hemidictyum (formerly placed in the WoodsiaceaeWoodsiaceaeWoodsiaceae or Cliff Fern is a family of fern within the Aspleniales order....
but shown to be part of the Asplenium clade) - Hymenasplenium