Phylogenomics and biogeography of Catalpa (Bignoniaceae) reveal incomplete lineage sorting and three dispersal events

•Catalpa is a monophyletic group that contains two main clades, section Catalpa and section Macrocatalpa.•The position of Catalpa ovata differs in the topologies derived from the analysis of the chloroplast and nuclear datasets, suggesting incomplete lineage sorting.•Biogeographic studies indicated that three dispersal events are necessary to explain the current distribution of Catalpa.