Character reconstruction and re-circumscription of the genus Convolvulus L. (Convolvulaceae).

Phylogenetic studies in the last two decades have demonstrated the non-monophyly of Convolvulus (~200 spp.), with Calystegia (~25 spp.) nested in it. However, no systematic progress has been made to resolve the non-monophyly of the genus and, as a consequence, at the present both Calystegia and a non-monophyletic Convolvulus are formally recognized. In this study, we explore a more adequate classification of Convolvulus. We investigate the molecular phylogenetic relationships between species of Convolvulus and Calystegia through a well-sampled and resolved phylogenetic analysis of nuclear ITS. Additionally, we explore morphological synapomorphies that could support the recognition of genera or sections through the parsimony optimization of seven morphological traits suggested as taxonomically informative for the genus, and we evaluate the chromosome number evolution. Two large clades were recovered that are mostly characterized by the habit, leaf base, and presence/absence of a petiole. We also discuss these results considering biogeographic patterns previously recovered for the group. In a reclassification of Convolvulus, we propose combining Calystegia in Convolvulus, with the recognition of the two larger clades as sections Convolvulus and Orthocaulus. This results in six new names, 29 new combinations and 29 re-establishments.