Searching for monophyly in the subgeneric classification systems of Columnea (Gesneriaceae).

The use of morphological characters to define species, genera, and higher taxa within the Gesneriaceae has often been problematic with convergences causing unrelated taxa to be classified together. Recent molecular phylogenetic analyses have allowed greater insights into relationships across the family and as a result better systems of classification that reflect the common ancestry of taxa rather than convergent evolutionary history have been proposed. Columnea is the largest Neotropical genus in Gesneriaceae subfamily Gesnerioideae and has had a complex and confusing taxonomic history. The species that are now considered Columnea have been placed in 14 genera and at times up to nine sections within the genus. More recently it has been recognized as five genera or a single genus with six sections. The phylogenetic analyses presented here sampled 68 species and for the first time resolved relationships among them. None of the recent subgeneric classification systems are in complete agreement with the phylogenetic relationships. The results here also indicate that there may be greater cryptic speciation in Columnea than had previously been assumed as some morphologically determined species are not recovered as monophyletic. Although our sampling consists of only two morphologically divergent species from Jamaica, they are supported as sister, implying that the endemic Columnea species in Jamaica may be derived from a single introduction event.