Molecular phylogenetics and character evolution of Cannabaceae

Cannabaceae includes ten genera that are widely distributed in tropical to temperate regions of the world. Because of limited taxon and character sampling in previous studies, intergeneric phylogenetic relationships within this family have been poorly resolved. We conducted a molecular phylogenetic study based on four plastid loci (atpB-rbcL, rbcL, rps16, trnL-trnF) from 36 ingroup taxa, representing all ten recognized Cannabaceae genera, and six related taxa as outgroups. The molecular results strongly supported this expanded family to be a monophyletic group. All genera were monophyletic except for Trema, which was paraphyletic with respect to Parasponia. The Aphananthe clade was sister to all other Cannabaceae, and the other genera formed a strongly supported clade further resolved into a Lozanella clade, a Gironniera clade, and a trichotomy formed by the remaining genera. Morphological ancestral state reconstructions indicated the complex evolution pattern of most analyzed morphological characters, and it is difficult to identify morphological synapomorphies for most clades within Cannabaceae