Caddah , Mayara Krasinski , Michelangeli, Fabián Armando , Goldenberg, Renato .
Taxonomic and phylogenetic studies on Miconia sect. Glossocentrum (Melastomataceae).
Melastomataceae is one of the most diverse families of flowering plants. Miconia is its biggest genus, comprising about 1070 species and along with other 17 related genera it comprises the tribe Miconieae, reaching over than 1800 species. The most recent revision of the family was conducted by Cogniaux over than a century ago, when Miconia was composed of less than half of the species currently known. Recent phylogenetic insights advocate for a new approach for the infrafamiliar classification, suggesting that Miconia is a complex polyphyletic genus, with other large genera such as Leandra, Clidemia, Ossaea, Tococa, Conostegia, and several others embedded within it. Similarly, recent analyses show a lack of support for the infrageneric classification of Miconia. Miconia sect. Glossocentrum has about 90 species, distributed from Central America and Caribbean Islands to Southern Brazil, Argentina and Paraguay. The section is characterized by short and linear stamens, 1-porate, with innapendiculate or just dorsally appendiculate connectives. Here we present a phylogenetic study of Miconia sect. Glossocentrum using four plastidial (trnS-G, accD-psaI, psbI-K and atpF-H) and two nuclear (ETS and ITS) loci.These analyses reveal that the section is highly polyphyletic, but about half of the species form a well-supported clade, the Miconia discolor group. This group can be morphologically characterized by its glomerulate or scorpioid inflorescences, stamens without conspicuous appendices in the connectives, leaves with the abaxial surface moderately to densely covered by branched hairs, and a distribution restricted to the Atlantic Forest and associated biomes. However, no specific morphological character or character combination is able to completely circumscribe the clade, mirroring the problematic morphological circumscriptions of most genera and sections within tribe. The species of section Glossocentrum with regular inflorescences, glabrous leaves, and/or wide distribution are resolved far away from the Miconia discolor group, and do not form a cohesive group.
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1 - State University of Campinas, Plant Biology, Rua Monteiro Lobato, 255, Cidade Universitária Zeferino Vaz, Campinas, SP, 13083970, Brazil
2 - The New York Botanical Garden, Institute Of Systematic Botany, 2900 Southern Blvd., Bronx, NY, 10458, USA
3 - Universidade Federal do Paraná, Botânica, Campus Politécnico, Jardim das Américas, Curitiba, PR, 81531970, Brazil
Presentation Type: Oral Paper:Papers for Sections
Location: Lindell B/Chase Park Plaza
Date: Tuesday, July 12th, 2011
Time: 9:00 AM