Aronia Medik. (chokeberry, Rosaceae) is a genus of woody shrubs with two or three North American species. Species boundaries and relationships between species of Aronia are frequently under question. The only European species in the genus, A. mitschurinii A.K.Skvortsov & Maitul., is suggested to be an inter-generic hybrid. In order to clarify the relationships between species of Aronia, we performed several morphometric and molecular analyses and found that the molecular and morphological diversity within data on American Aronia is low, and species boundaries are mostly not clearly expressed. Whereas morphology is able to separate American species from A. mitschurinii, there is no support for such discrimination from the molecular data; our analyses did not reveal evidence of A. mitschurinii hybrid origin. We believe that higher-resolution markers are needed to resolve species boundaries and putative hybridization events.

The tribe Plantagineae (Lamiales) is a group of plants with worldwide distribution, notorious for its complicated taxonomy and still unresolved natural history. We describe the result of a broadly sampled phylogenetic study of tribe. The expanded sampling dataset is based on the trnL-F spacer, rbcL, and ITS2 markers across all three included genera (Aragoa, Littorella and Plantago) and makes this the most comprehensive study to date. The other dataset uses five markers and provides remarkably good resolution throughout the tree, including support for all of the major clades. In addition to the molecular phylogeny, a morphology database of 114 binary characters was assembled to provide comparison with the molecular phylogeny and to develop a means to assign species not sampled in the molecular analysis to their most closely related species that were sampled. Based on the molecular phylogeny and the assignment algorithm to place unsampled species, a key to sections is presented, and a revised classification of the tribe is provided. We also include the description of new species from North America.

The Buxaceae constitute a morphologically diverse phylogenetic lineage of six genera, which includes about 140 species. The most well-known genera are Buxus, Sarcococca, and Pachysandra. Few species of woody Styloceras grow on mid-elevations in the Andes mountains region. Didymeles, with three species endemic to Madagascar, and the monotypic Haptanthus from Honduras, are the most unusual members of the group. The infra-familial classification of Buxaceae is controversial, and molecular data about many species, especially Old World, is still lacking. We used broad taxonomic sampling and molecular data from four chloroplast markers, and the nuclear ribosomal ITS to estimate their phylogeny. These data provide phylogenetic placements of 50 species and enabled better estimates of boundaries in Buxaceae. We described two subfamilies, one monotypic genus, two Buxus subgenera, and one new species of Didymeles from Madagascar.

The tribe Plantagineae (Lamiales) is a group of plants with worldwide distribution, notorious for its complicated taxonomy, still unresolved natural history, and a trend of morphologic reduction and simplification. This tribe includes the plantains (Plantago), the small aquatic Littorella, and the northern Andean shrubs Aragoa. Some Plantago lineages exhibit remarkably high diversification rates, which further adds to the complicated classification, and the worldwide distribution of these plants raises numerous questions related to vicariance and dispersal. In this work, we present the broadest phylogeny of the group to date and discuss the evolutionary, morphological, and biogeographical implications of our phylogenetic results, including the description of two new species from the Americas.