Abstract Detail


Black, Bertrand [1], Sundue, Michael [2].

A phylogenetic revision of the Athyrium filix-femina clade (Athyriaceae) in the Americas.

Athyrium filix-femina (Athyriaceae) is distributed across the temperate regions of the northern hemisphere and montane regions of the neotropics. In the Americas, it forms a cryptic species complex to which a satisfactory taxonomic treatment has remained elusive, despite several previous studies. Currently, circumscription of the American taxa varies from one to seven species. To explore patterns of speciation, introgression, and reticulate evolution of this species complex, we integrated next-generation sequence data with morphology and climate data. We evaluated the utility of these data sets for studies addressing species delimitation and divergent evolution of infraspecific taxa across geographic space. Our molecular phylogenetic results indicate that there are four geographically distinct clades in North America and two in South America. The taxa in each clade can be characterized by their ecology and geographic distributions, except in one overlapping region where hybridization appears to occur. Two taxa, A. filix-femina var. californicum and the Mexican A. bourgaei, were recovered in the same clade and may pertain to the same species as evidenced by their overlapping morphology and contiguous ranges. Unexpectedly, European taxa were found to be nested in an entirely American clade, which indicates evidence for an American origin of the Eurasian A. filix-femina. This ongoing study exemplifies the importance of applying modern and integrative total evidence approaches to groups with complex and cryptic taxonomic histories. By better understanding the species boundaries within this cryptic group of ferns, we are able to provide clearer insights into the evolutionary history of this familiar fern in the Americas.

1 - University of Vermont, Plant Biology, 63 Carrigan Drive, Burlington, VT, 05401, United States
2 - University of Vermont, Plant Biology, 63 Carrigan Drive, Apt , Burlington, VT, 05405, United States

reticulate evolution
fern diversity.

Presentation Type: Oral Paper
Number: PTR2002
Abstract ID:1041
Candidate for Awards:Edgar T. Wherry award

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