Phylogenetic analysis of morphological characters in Ourisia (Plantaginaceae):: Taxonomic and evolutionary implications

Ourisia Comm. ex. Juss. (Plantaginaceae; Scrophulariaceae s.l.) is a genus of herbaceous or suffruticose species that occur largely in high-elevation habitats of Andean South America, New Zealand, and Tasmanai. Recent molecular phylogenetic data have clarified evolutionary relationships within Ourisia and provided high support for the recognition of two subgenera based primarily on habit, i.e., Ourisia subg. Ourisia (25 herbaceous species) and Ourisia subg. Suffruticosae Meudt (three suffruticose species). To investigate the utility of morphological data in comparison to molecular data for phylogeny and subgeneric taxonomy, phylogenetic hypotheses were generated using 20 morphological characters for all 33 taxa of Ourisia using Melosperma Benth. as an outgroup. Additional phylogenetic hypotheses were generated by combining the morphological data with molecular data for the 29 species (plus Melosperma) for which the latter were available. With respect to phylogeny, morphological data are congruent with molecular data but generally provide less resolution. Morphological data are informative regarding infrageneric taxonomy and show that at least six morphological characters in addition to habit support the delimitation of the two subgenera. Finally, morphological characters of interest were traced onto the molecular phylogeny. Evolution of these and other characters are discussed in light of the various phylogenetic results.