Judd, Walter , Bush, Catherine , Fritsch, Peter , Kron, Kathleen .
Phylogenetic relationships and morphological evolution in the Gaultherieae: combined molecular and morphological data.
The wintergreen group (Gaultherieae) previously has been shown to be monophyletic and include the currently recognized genera: Chamaedaphne, Diplycosia, Eubotrys, Gaultheria, Leucothoe and Tepuia. This clade can be characterized by the combined possession of pedicels articulated with the flower, usually axillary inflorescences, flowers on the shoots of the previous season and anthers often with 4 apical appendages. In this study 57 morphological characters of 65 species of Gaultheria representing all sections (10) and series (22) currently recognized, three species of Diplycosia and two species of Tepuia were analyzed with maximum parsimony (MP; PAUP 4.0). Sequence data from the chloroplast genes matK and ndhF, and the nuclear ribosomal ITS were analyzed using MP and maximum likelihood criteria (ML; RAxML). Combined morphology and molecular data were analyzed using MP. Eubotrys racemosa and Leucothoe fontanesiana were used as outgroups. Analysis of the morphological data alone resulted in a highly unresolved tree with most species in a large polytomy. Results of the combined molecular and morphological data resulted in a well-resolved tree that indicates Gaultheria as currently recognized is paraphyletic. Diplycosia and Tepuia are each monophyletic but are nested within a clade that also includes species of Gaultheria. Diplycosia is sister to G. procumbens and Tepuia is sister to the G. hispidula and G. suborbicularis pair. A potential synapomorphy for this clade is the presence of connate bracteoles. Although most morphological characters show homoplasy, some clades can be characterized by a combination of characters, e.g., the G. ulei to G. thymifolia clade with small leaves, inflorescences in fascicles and apical bracteoles. Based on the results a new classification of the Gaultherieae is proposed that includes Diplycosia and Tepuia within Gaultheria.
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1 - University of Florida, Department of Biology, Po Box 118526, Gainesville, FL, 32611, USA
2 - Valdosta State University, Biology, 1500 N. Patterson St. , Valdosta, GA, 31698, USA
3 - California Academy Of Sciences, 55 Music Concourse Drive, SAN FRANCISCO, CA, 94118-4503, USA
4 - Wake Forest University, Department Of Biology, 1834 Wake Forest Road, WINSTON-SALEM, NC, 27106, USA
Presentation Type: Oral Paper:Papers for Sections
Location: Lindell B/Chase Park Plaza
Date: Monday, July 11th, 2011
Time: 4:30 PM