ibclogo XVI International Botanical Congess


Abstract Number: 4485
Poster No. = 653


PHYLOGENY AND BIOGEOGRAPHY OF NEMOPHILA NUTT. (HYDROPHYLLACEAE)


D. Megan Helfgott, Jack L. Neff and Beryl B. Simpson Section of Integrative Biology, University of Texas, Austin, Texas, 78713


Is geographic proximity always a good indicator of phylogenetic relatedness? To examine this question we estimated the evolutionary relationships among the 11 species within the genus Nemophila Nutt. (Sensu Constance 1941). All members of Nemophila Nutt. Are annual herbs native to north America. Geographically, nine species occur west of the Rockies while two species (N. phacelioides and N. microcalyx) are disjunct in the southeastern united State from central Texas to Virginia. In our phylogenetic study we used sequence data from the nuclear ribosomal ITS region and the chloroplast trnK intron. Our results indicate that Nemophila is monophyletic, however the two eastern species are not sister taxa, suggesting two separate dispersal or vacarant events.


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