Recent Topics Posters
Condack, Joao P. S. , Barrington, David S. , Sylvestre, Lana .
Phylogeny and biogeography of Polystichum Roth. (Dryopteridaceae) with emphasis on the species occurring at the Brazilian center of diversity.
The "Serra do Mar" and "Serra da Mantiqueira" are the two main mountain ranges in southeastern Brazil. These ranges run nearly parallel to the ocean and are separated from the western South American mountain ranges by a minimum of 1400 miles. High biologic diversity and proportion level of endemic species characterize these regions. The Brazilian coastal ranges are one of the three main neotropical areas where the diversity of ferns is greatest. Although these areas have been popular among botanists since the nineteenth century, many species are still being described and many genera lack a taxonomic revision. The fern genus Polystichum Roth stands out as a particularly neglected group in the Brazil; where there are 23 named species and no recent taxonomic treatment. Morphological complexity and wealth of taxonomic problems, coupled with the critical conservation status of several endemic species, make Brazilian Polystichum a high priority for systematic work. Polyploids and sterile hybrids are commonly reported for the genus and have been one of the reasons for its taxonomic complexity. Our preliminary isozyme assays have shown that hybridization and/or polyploidy also complicate the interpretation of the Brazilian species. Preliminary molecular results have also demonstrated that the Brazilian Polystichum flora has at least two distinct origins. The lineage including most of the twice-pinnate species is related to the exindusiate Andean clade. On the other hand, the two once-pinnate, indusiate species have affinities with geographically remote species from other southern regions. A broader analysis including morphological and molecular datasets from an increased number of herbarium sheets and the use of additional chloroplast and nuclear genes will contribute to better phylogenetic resolution, species circumscription, and a more precisely defined taxonomy for the Brazilian species. The results of this study will contribute for a better understanding of the genus in Brazil and the phylogenetic relationship among Polystichum lineages from the southern continents.
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The Polystichum Homepage
1 - Museu Nacional / UFRJ, Programa de Pós Graduação em Botânica, Quinta da Boa Vista S/N. São Cristóvão, Rio de Janeiro, RJ, 20940-040, Brazil
2 - University of Vermont, Plant Biology Department, Jeffords Hall , 63 Carrigan Dr. , Burlington, VT, 05405, United States
3 - Universidade Federal do Rio de Janeiro, Departamento de Botânica, Av. Brigadeiro Trompowsky S/N. Cidade Universitária, Rio de Janeiro, RJ, 21941-490, Brazil
Presentation Type: Recent Topics Poster
Location: Hall A/Convention Center
Date: Monday, August 2nd, 2010
Time: 5:30 PM