Browsing by Subject "DRYOPTERIDACEAE"

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    A plastid phylogeny of the cosmopolitan fern family cystopteridaceae (Polypodiopsida)
    (Systematic Botany, 2013-06-01) Rothfels, CJ; Windham, MD; Pryer, KM
    Among the novel results of recent molecular phylogenetic analyses are the unexpectedly close evolutionary relationships of the genera Acystopteris, Cystopteris, and Gymnocarpium, and the phylogenetic isolation of these genera from Woodsia. As a consequence, these three genera have been removed from Woodsiaceae and placed into their own family, the Cystopteridaceae. Despite the ubiquity of this family in rocky habitats across the northern hemisphere, and its cosmopolitan distribution (occurring on every continent except Antarctica), sampling of the Cystopteridaceae in phylogenetic studies to date has been sparse. Here we assemble a three-locus plastid dataset (matK, rbcL, trnG-R) that includes most recognized species in the family and multiple accessions of widespread taxa from across their geographic ranges. All three sampled genera are robustly supported as monophyletic, Cystopteris is strongly supported as sister to Acystopteris, and those two genera together are sister to Gymnocarpium. The Gymnocarpium phylogeny is deeply divided into three major clades, which we label the disjunctum clade, the robertianum clade, and core Gymnocarpium. The Cystopteris phylogeny, similarly, features four deeply diverged clades: C. montana, the sudetica clade, the bulbifera clade, and the fragilis complex. Acystopteris includes only three species, each of which is supported as monophyletic, with A. taiwaniana sister to the japonica/tenuisecta clade. Our results yield the first species-level phylogeny of the Cystopteridaceae and the first molecular phylogenetic evidence for species boundaries. These data provide an essential foundation for further investigations of complex patterns of geographic diversification, speciation, and reticulation in this family. © Copyright 2013 by the American Society of Plant Taxonomists.
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    A revised family-level classification for eupolypod II ferns (Polypodiidae: Polypodiales)
    (Taxon, 2012-01-01) Rothfels, CJ; Sundue, MA; Kuo, L; Larsson, A; Kato, M; Schuettpelz, E; Pryer, KM
    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.
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    Low-copy nuclear data confirm rampant allopolyploidy in the cystopteridaceae (Polypodiales)
    (Taxon, 2014-10-01) Rothfels, CJ; Johnson, AK; Windham, MD; Pryer, KM
    © International Association for Plant Taxonomy (IAPT) 2014. Here we present the first nuclear phylogeny for Cystopteridaceae (Polypodiales), using the single-copy locus gapCp “short”. This phylogeny corroborates broad results from plastid data in demonstrating strong support for the monophyly of the family’s three genera—Cystopteris, Acystopteris, and Gymnocarpium—and of the major groups within Cystopteris (C. montana, the sudetica and bulbifera clades, and the C. fragilis complex). In addition, it confirms the rampant hybridization (allopolyploidy) that has long been suspected within both Cystopteris and Gymnocarpium. In some cases, these data provide the first DNA-sequence-based evidence for previous hypotheses of polyploid species origins (such as the cosmopolitan G. dryopteris being an allotetraploid derivative of the diploids G. appalachianum and G. disjunctum). Most of the allopolyploids, however, have no formal taxonomic names. This pattern is particularly strong within the C. fragilis complex, where our results imply that the eight included accessions of “C. fragilis” represent at least six distinct allopolyploid taxa.