Author:
Qjure
Book:
Qjurious
Type:
Info
Chapter:
3-433.10.00
Gleicheniales
Region: Asia, Pacific.
Habitat: tropical.
Genera
Dipteridaceae: 2 genera, Cheiropleuria, Dipteris.
Gleicheniaceae: 6 genera, Dicranopteris, Diplopterygium, Gleichenella, Gleichenia, Sticherus, Stromatopteris.
Matoniaceae: 2 genera, Matonia, Phanerosorus.
Botany
Identification: root steles having 3 to 5 protoxylem poles; antheridia with 6 to 12 narrow, twisted or curved cells in their walls.
Leaves: typical fern fronds to resembling leaves of palm trees, to undivided leaves.
Taxonomy
Smith in 2006 placed Gleicheniales in the class Polypodiopsida, with 3 families, Dipteridaceae, Gleicheniaceae, and Matoniaceae. Christenhusz in 2011 placed Gleicheniales in the subclass Polypodiidae, with the same families. PPG I in 2016 used the same placement.
In historical treatments, the order has sometimes been treated as a subclass Gleicheniatae of the Pteridopsida, with the taxa treated as families here upranked to orders, so that a distinct subclass can be established for the leptosporangiate ferns.
In other treatments, they were expanded to include the filmy ferns (order Hymenophyllales), as well as the similar-looking genus Hymenophyllopsis (as order Hymenophyllopsidales). The resultant group was treated as class Gleichenopsida alongside the Pteridopsida, which would then be limited to the leptosporangiate ferns. However, this class is not monophyletic but rather a basal grade, retaining ancient traits among the living ferns. Irrespective of their modern taxonomic treatment, the Gleicheniales were formerly included in the order Polypodiales. But the ferns in the loose sense are much too diverse a group to be shoehorned into one taxon at such a low rank.
The formerly independent families Dicranopteridaceae and Stromatopteridaceae are generally included in the Gleicheniaceae, whereas the Dipteridaceae and Matoniaceae, although closely related, are considered separate families by most authors.
Literature
Pryer, K. M. & Schuettpelz, E. & others; Phylogeny and evolution of ferns (monilophytes) with a focus on the early leptosporangiate divergences.; American Journal Botany, 91, 1582–1598; 2004.
Schuettpelz, E. & Korall, P. & Pryer, K. M.; Plastid atpA data provide improved support for deep relationships among ferns; Taxon 55; 2006
Schneider, H.; Vergleichende Wurzelanatomie der Farne, Ph.D. dissertation; Universitat Zürich, Shaker, Aachen; 1996.