摘要The north temperate region was characterized by a warm climate and a rich thermophilic flora be-fore the Eocene,but early diversifications of the temperate biome under global climate change and biome shift remain uncertain.Moreover,it is becoming clear that hybridization/introgression is an important driving force of speciation in plant diversity.Here,we applied analyses from bio-geography and phylogenetic networks to ac-count for both introgression and incomplete lin-eage sorting based on genomic data from the New World Vitis,a charismatic component of the temperate North American flora with known and suspected gene flow among species.Biogeo-graphic inference and fossil evidence suggest that the grapes were widely distributed from North America to Europe during the Paleocene to the Eocene,followed by widespread extinction and survival of relicts in the tropical New World.During the climate warming in the early Miocene,a Vitis ancestor migrated northward from the refugia with subsequent diversification in the North American region.We found strong evi-dence for widespread incongruence and retic-ulate evolution among nuclear genes within both recent and ancient lineages of the New World Vitis.Furthermore,the organellar genomes showed strong conflicts with the inferred species tree from the nuclear genomes.Our phyloge-nomic analyses provided an important assess-ment of the wide occurrence of reticulate in-trogression in the New World Vitis,which potentially represents one of the most important mechanisms for the diversification of Vitis spe-cies in temperate North America and even the entire temperate Northern Hemisphere.The sce-nario we report here may be a common model of temperate diversification of flowering plants adapted to the global climate cooling and fluc-tuation in the Neogene.