2.5 Ancestral Area Reconstruction
To explore the biogeographic history of Notholirion plants, we used three regions based on the paleogeographic and climatic evidence, geographic distribution and floral composition throughout the Himalayas-Hengduan Mountains (HHM) for ancestral area reconstruction(Buerki et al., 2012; Tu, Volis, Dillon, Sun, & Wen, 2010; H. Y. Zheng et al., 2021): (A) southern Himalayas, (B) eastern Himalayas, (C) Hengduan Mountains. The Statistical Dispersal-Vicariance (S-DIVA) analysis as implemented in the RASP v4(Y. Yu, Blair, & He, 2020) was used for the reconstruction. We used the BI tree based on the cpDNA datasets (obtained by phylogenetic analyses) for the S-DIVA analyses. The uncertainty in the root areas of an outgroup can lead to biased inferences for the crown node of the ingroups(Y. Yu, Harris, Blair, & He, 2015), outgroups were removed before ancestral-state reconstruction. To explore the effects of area constraints, the maximum number of areas at each node was set to two.