Kron, Kathleen , Judd, Walter , Bush, Catherine , Fritsch, Peter , Lu, Lu , Li, De-Zhu .
A new classification of the wintergreen group (Gaultherieae) based on phylogenetic relationships and morphology.
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 currently recognized sections (10) and series (22), 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, maximum likelihood (ML; RAxML) and Bayesian analysis (MrBayes). Combined morphological 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 a paraphyletic Gaultheria (as currently recognized. 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 - 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 - G. thymifolia clade with small leaves, inflorescences in fascicles and apical bracteoles. Based on these results a new classification of the Gaultherieae is proposed that includes Diplycosia and Tepuia within Gaultheria.
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1 - University of Florida, Florida Museum of Natural History, Gainesville, FL, 32611, USA
2 - Wake Forest University, Department Of Biology, 1834 Wake Forest Road, WINSTON-SALEM, NC, 27106, USA
3 - California Academy Of Sciences, 55 Music Concourse Drive, SAN FRANCISCO, CA, 94118-4503, USA
4 - Kunming Institute of Botany, Chinese Academy of Sciences, Key Laboratory for Biodiversity and Biogeography, 132 Lanhei Road, Heilongtan, Kunming, Yunnan, 650204, China
Presentation Type: Oral Paper:Papers for Sections
Location: Delaware C/Hyatt
Date: Wednesday, July 11th, 2012
Time: 2:45 PM