Phylogenetic Congruence and Discordance Among One Morphological and Three Molecular Data Sets from Pontederiaceae

A morphological data set and three sources of data from the chloroplast genome (two genes and a restriction-site survey) were used to reconstruct the phylogenetic history of the Pickerelweed family Pontederiaceae. The chloroplast data are converging to a single tree, presumably the true chloroplast phylogeny of the family. Unrooted trees estimated from the three chloroplast data sets were identical or extremely similar in shape to each other, mostly robustly supported and there was no evidence of significant heterogeneity among them. The few topological differences seen among unrooted trees from each chloroplast data set are probably artifacts of sampling error on short branches. Despite well documented differences in rates of evolution for different characters in individual data sets, equally weighted parsimony therefore permits accurate reconstructions of chloroplast relationships in Pontederiaceae. A separate morphology-based data set yielded trees that were very different from the ...