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A revised family-level classification for eupolypod II ferns (Polypodiidae: Polypodiales)
Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Systematic Biology.
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2012 (English)In: Taxon, ISSN 0040-0262, Vol. 61, no 3, 515-533 p.Article in journal (Refereed) Published
Abstract [en]

We present a family-level classification for the eupolypod II clade of leptosporangiate ferns, one of the two major lineages within the Eupolypods, and one of the few parts of the fern tree of life where family-level relationships were not well understood at the time of publication of the 2006 fern classification by Smith & al. Comprising over 2500 species, the composition and particularly the relationships among the major clades of this group have historically been contentious and defied phylogenetic resolution until very recently. Our classification reflects the most current available data, largely derived from published molecular phylogenetic studies. In comparison with the five-family (Aspleniaceae, Blechnaceae, Onocleaceae, Thelypteridaceae, Woodsiaceae) treatment of Smith & al., we recognize 10 families within the eupolypod II clade. Of these, Aspleniaceae, Thelypteridaceae, Blechnaceae, and Onocleaceae have the same composition as treated by Smith & al. Woodsiaceae, which Smith & al. acknowledged as possibly non-monophyletic in their treatment, is circumscribed here to include only Woodsia and its segregates; the other "woodsioid" taxa are divided among Athyriaceae, Cystopteridaceae, Diplaziopsidaceae, Rhachidosoraceae, and Hemidictyaceae. We provide circumscriptions for each family, which summarize their morphological, geographical, and ecological characters, as well as a dichotomous key to the eupolypod II families. Three of these families-Diplaziopsidaceae, Hemidictyaceae, and Rhachidosoraceae-were described in the past year based on molecular phylogenetic analyses; we provide here their first morphological treatment.

Place, publisher, year, edition, pages
2012. Vol. 61, no 3, 515-533 p.
Keyword [en]
Athyriaceae, Diplaziopsis, ferns, Rhachidosorus, taxonomy, Woodsiaceae
National Category
Biological Sciences
URN: urn:nbn:se:uu:diva-177615ISI: 000305439100003OAI: oai:DiVA.org:uu-177615DiVA: diva2:541416
Available from: 2012-07-17 Created: 2012-07-17 Last updated: 2015-01-23Bibliographically approved
In thesis
1. Systematics of Woodsia: Ferns, bioinformatics and more
Open this publication in new window or tab >>Systematics of Woodsia: Ferns, bioinformatics and more
2014 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Ferns are one of the three main clades of vascular plants. They have few easily studied morphological characters, reflected in a historically unstable classification. The fern genus Woodsia is known to have a complex evolutionary history including numerous polyploid taxa and hybrids. It is a cosmopolitan group of small rock loving ferns mainly found in montane areas.

This thesis aims at analyzing the patterns of diploid and polyploid evolution in Woodsia and to resolve and classify the relationships of Woodsiaceae and the other families in the large fern clade Eupolypods II.

The Eupolypods II family relationships were inferred with DNA sequences from 81 specimens representing all major lineages. This resulted in the first well supported phylogeny of this clade and revealed Woodsiaceae to be non-monophyletic. The genera previously placed in this family were reclassified into five new or resurrected families. Swedish fern genera that have changed family classification are Woodsia (hällebräknar), now in the monogeneric family Woodsiaceae, Athyrium (majbräknar), now  in Athyriaceeae and Cystopteris (stenbräknar) and Gymnocarpium (ekbräknar) now in Cystopteridaceae.

To analyze the evolution of Woodsia, phylogenies were produced from five plastid and two nuclear regions sequenced from 188 specimens. The results show that most taxa in Woodsia are polyploid. Polyploidization is the most common mode of speciation in the genus with an estimated polyploid speciation rate of 54%. The polyploids are mostly young and many of the polyploid taxa seem to have formed multiple times. The results also address several taxonomic and biogeographic questions.

In the process of the work we made methodological advancements and developed 20 new low copy nuclear marker regions as well as a software pipeline for finding primers in transcriptome datasets. The alignment editor software AliView was developed for handling the increasing size datasets in a user friendly way.

In conclusion this thesis provides new insights into the complexities of the evolution of a fern genus in which much of the diversity is accommodated in young species formed through polyploidization. It provides a framework of phylogenetic relationships at different levels that both answers long standing questions and generates new ones.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2014. 36 p.
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 1182
ferns, Eupolypods II, Woodsia, phylogeny, biogeography, polyploidy, polyploid speciation, classification, alignment
National Category
Biological Systematics
Research subject
Biology with specialization in Systematics
urn:nbn:se:uu:diva-232233 (URN)978-91-554-9040-9 (ISBN)
Public defence
2014-10-31, Lindahlsalen, Norbyvägen 18B, Uppsala, 10:00 (English)
Swedish Research Council Formas, 2006-429 and 2010-585
Available from: 2014-10-10 Created: 2014-09-15 Last updated: 2015-01-23

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