Abstract Detail

Systematics Section

Penneys, Darin S. [1], Almeda, Frank [2], Michelangeli, Fabian A. [3].

Progress towards a comprehensive phylogenetic analysis and revised classification of the Melastomataceae.

Melastomataceae, with ca. 170 genera and 5000 species, are the eighth largest family of angiosperms. Melastomataceae are monophyletic, and are mostly characterized by their medullary vascular bundles, acrodromous venation, hypanthia, stamens folded in bud, poricidal anthers, and tricolporate pollen grains. The family was last monographed by Cogniaux in 1891, and subsequently, an additional ca. 55 accepted genera and 2000 species have been described. Only a small proportion of this diversity has been monographed. A consideration of extralimital taxa and putative relationships has been beyond the scope of geographically defined floristic treatments. For most, tribal and generic circumscriptions are uncertain, as their monophyly has never been tested. The classification of Cogniaux remains widely cited, though modern schemes have been proposed based upon phylogenetic analyses using limited numbers of morphological characters, or in the case of molecular studies, limited taxonomic sampling at the generic level. We have sequenced DNA from over 650 species in ca. 140 genera for nrITS, and similar datasets are being compiled for cpDNA accD-psaI, ndhF, rbcL, and rpl16. Our preliminary results from individual and variously combined analyses largely corroborate the conclusions of recent phylogenetic studies on traditional tribes, some of which have had their circumscriptions slightly modified (e.g., Blakeeae and Miconieae), reduced (Microlicieae), or have been recently proposed based upon modern studies (Henrietteeae). However, modifications to previous classifications are necessary. In some cases, these changes may involve generic realignments, but more dramatically, our results indicate that many genera have been improperly assigned to tribes, and that some tribes are paraphyletic or polyphyletic. A revised classification of the Melastomataceae is therefore necessary. Based upon this multi-gene phylogenetic analysis sampling of ca. 140 genera, a new family level taxonomy is forthcoming.

Broader Impacts:

Related Links:
Melastomataceae of the World

1 - California Academy of Sciences, Department of Botany, 55 Music Concourse Drive, Golden Gate Park, San Francisco, CA, 94118, USA
2 - California Academy of Sciences, Department of Botany, 55 Music Concourse Drive Golden Gate Park, San Francisco, California, 94118, USA
3 - The New York Botanical Garden, Lewis B. and Dorothy Cullman Program for Molecular Systematic Studies, 200th St. & Southern Blvd., Bronx, New York, 10458-5126, USA

Keywords:
Melastomataceae
molecular phylogenetics
classification.

Presentation Type: Oral Paper:Papers for Sections
Session: 56
Location: 556B/Convention Center
Date: Wednesday, August 4th, 2010
Time: 4:00 PM
Number: 56012
Abstract ID:704