Hooper, Elisabeth , Yatskievych, George , Huiet, Layne , Windham, Michael , Pryer, Kathleen .
Into or out of Africa? What do molecular data reveal about the identity and biogeographic origin of Aleuritopteris farinosa (Forssk.) Fee (Pteridaceae)?
Aleuritopteris farinosa is the type species of Aleuritopteris and yet it has a geographic distribution that is atypical for the genus. Although most of the 40+ species in Aleuritopteris have a Sino-Himalayan distribution, A. farinosa is found in continental Africa (extending to Yemen, Madagascar, and La Reunion) and the Americas (Mexico to S. America). As part of an ongoing molecular phylogenetic study of Aleuritopteris using three plastid gene markers (rbcL, atpA, and trnGR) we have been investigating the relationship between A. farinosa and its Asian congeners, as well as the relationship between Old and New World elements within A. farinosa itself. Results thus far confirm that A. farinosa is nested within a monophyletic group of approximately 14 species informally called the A. farinosa complex. At one time this clade was treated as a single, broadly-distributed, heterogeneous species (A. farinosa sensu lato), but more recently the Asian elements have been segregated as distinct species and A. farinosa sensu stricto has been reserved for the African/American taxon. There has been controversy, however, concerning the true identity of A. farinosa s.s. This taxon is morphologically quite variable across its range, leading some to recognize segregate taxa. Moreover, there are at least two known cytotypes in East Africa (a triploid apomict and a sexual tetraploid), suggesting the occurrence of reticulate evolution in the group. To investigate this situation, we have been evaluating the genetic relationship among Old and New World elements of A. farinosa s.s. One surprising early result suggests that New World collections referred to A. farinosa are more closely related to certain Asian species than they are to collections of A. farinosa from Africa. Here we report the results of additional sampling within A. farinosa s.s. and discuss their significance with respect to taxonomic circumscription, phylogenetic position, and biogeographic origin of A. farinosa.
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1 - Truman State University, Department of Biology, Kirksville, MO, 63501, USA
2 - Missouri Botanical Garden, PO Box 299, St. Louis, MO, 63166-0299, USA
3 - Duke University, Department of Biology, Durham, NC, 27708, USA
Presentation Type: Oral Paper:Papers for Sections
Location: Waterman Room/Chase Park Plaza
Date: Monday, July 11th, 2011
Time: 10:45 AM