Conclusions
In conclusion, our population genetic analyses revealed that the two leaflet dichotomous similar species had high genetic differentiation but low gene flow with a deep divergence occurred in the late Miocene. We attributed this to the long-term geographical isolation by the RRFZ. After speciation, they experienced different population historical dynamics to respond climate fluctuations during the Pleistocene. Our study provides a new perspective that will be of interest in the future to find out the truth that the two species have the same pinnate bifurcation pattern, own high genetic differentiation and are adapted to their respective habitats, and how did they originate, based on genomic data.