Floristic composition
A comprehensive list of the native seed plants of the above floras was obtained from several floristic inventories (Peng 1998; Zhu & Yan 2009, 2012; Zhu 2015), the Flora of Yunnan (Wu 1977-2006), and the database of seed plants from herbarium of Kunming Institute of Botany, Chinese Academy of Sciences. The nomenclature of these species was checked and standardized according to The Plant List version 1.1 (TPL, available at http://www.theplantlist.org). All the intraspecific taxa (e.g., subspecies, variety and forma) and introduced species were excluded. In total, 9,370 seed plant species were included in this study, belonging to 1,860 genera and 212 families. Details about the data collection are described in Zhu (2012) and Liu et al. (2017), both of which discussed the biogeographical divergences among these three floras.