Publications by authors named "Keir M Wefferling"
Premise: The western North American fern genus Pentagramma (Pteridaceae) is characterized by complex patterns of ploidy variation, an understanding of which is critical to comprehending both the evolutionary processes within the genus and its current diversity.
Methods: We undertook a cytogeographic study across the range of the genus, using a combination of chromosome counts and flow cytometry to infer ploidy level. Bioclimatic variables and elevation were used to compare niches.
Premise Of The Study: Unrecognized variation in ploidy level can lead to an underestimation of species richness and a misleading delineation of geographic range. (Ranunculaceae) comprises a complex of hexaploids (6), rare nonaploids (9), and dodecaploids (12), all with unknown distributions. We delineate the geographic distribution and contact zones of the cytotypes, investigate morphologies of cytotypes and subspecies, and discuss the biogeography and evolutionary history of the polyploid complex.
View Article and Find Full Text PDFPremise Of The Study: This work surveys endocarp morphology of Menispermaceae in the context of a well-supported molecular phylogeny. The study is important since menispermaceous endocarps appear often in the fossil record and indicate the presence of a wet forest ecosystem. •
Methods: Three chloroplast regions were used to derive phylogenies for 53 genera and 60 species.
Premise Of The Study: Fossil leaves of Menispermaceae were previously described from the Paleocene of Colombia. Because of strong homoplasy of leaf characters, the fossils could not be placed more specifically within recognized clades, and additional data were needed to specify intrafamilial and paleogeographic relationships during the Paleocene.
Methods: Fossil endocarps of Menispermaceae were collected from the Cerrejón Formation, the recently discovered Bogotá flora, and Wyoming (∼60 Ma).