ibclogo XVI International Botanical Congess


Abstract Number: 6214
Session = 19.13.5


STRUCTURAL AND PHYLOGENETIC HOMOLOGY OF FLORAL FORMS IN THE LEGUME TRIBE AMORPHEAE


Michelle McMahon* and Larry Hufford, Washington State University


Accurate inferences in evolutionary biology require accurate hypotheses of structural and phylogenetic homology. Homology among the diverse floral forms in the legume tribe Amorpheae has been obscured by the evolution of novelty, such as the insertion of free petals onto fused stamens, and by the evolutionary loss of organs. Here we synthesize results from morphological study and preliminary phylogenetic analysis to assess the homology of floral traits in Amorpheae. We found petal-stamen synorganization to be structurally homologous among taxa in which it occurs, and our phylogenetic hypothesis, based on sequence data from the chloroplast gene matK, allows us to infer phylogenetic homology for the trait. This finding requires a reconsideration of generic limits within the tribe. Other traits that contribute to the diversity such as petal loss were found to be not phylogenetically homologous. We discuss these results in the context of the patterning of morphological evolution among clades within Amorpheae.


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