Neves, Susana S. .
Morphology, chromosome numbers and molecular evidence: problems in species circumscription in Bupleurum (Apiaceae).
Bupleurum L. (ca. 150 species; Apiaceae) is widely distributed in the Northern Hemisphere and shows great morphological and ecological diversity, particularly in the Mediterranean. Asian species are also numerous, but many are perennial herbs with similar morphology and small variation in a few inflorescence or leaf characters. Understanding of species limits in Asian Bupleurum has been hampered by the vast distribution of morphologically similar taxa and the lack of comparative studies among species of different countries or regions. My recent study of Asian herbarium collections of the genus, including types, indicates that misidentification or incorrect use of names is not uncommon. Morphological results have now been confirmed by analysis of DNA sequences. In some cases, application of species names remains uncertain and requires the study of type collections, which are dispersed in institutions of many countries. Many botanical institutions are publishing high-quality images of type specimens online; unfortunately, this invaluable effort is not being replicated everywhere. Problems of species concepts in Bupleurum are also evident by analysis of chromosome numbers, with inconsistent counts being sometimes associated to plant species that are poorly characterized. Available sequences also suggest some problems in species delimitation or, perhaps, misidentification. Physical access to vouchers of molecular data is problematic. Online access to good-quality images of molecular (or other) vouchers would be very useful for taxonomic research; perhaps this should be a requirement for future publication of molecular phylogenies. Here, I discuss the progress recently made on the molecular phylogenetic study of Bupleurum, with special attention to Asian taxa and chromosome number variation. I also discuss examples where the study of type specimens (and original descriptions) was critical to resolve long-standing questions of application of names.
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1 - ITQB - Universidade Nova de Lisboa, Instituto de Tecnologia Química e Biológica, Apartado 127, Oeiras, 2781-901, Portugal
Presentation Type: Oral Paper:Papers for BSA Sections
Location: Maybird/Cliff Lodge - Level C
Date: Wednesday, July 29th, 2009
Time: 2:45 PM