A PHYTOGEOGRAPHICAL ANALYSIS OF MAGNOLIACEAE

The Magnoliaceae consists of 7 genera and about 195 species disjuncted between the tropics to temperate of Asia and America. The family once occurred in almost all the north hemisphere. Its decline in Europe, Greenland, etc. is possibly due to the decrease of temperature caused by the regionalization of the global climate in the Tertiary as well as the serious destruction of the glacier in the Quaternary. The Magnoliaceae is well represented by abundant genera and species, rich endemic species, representatives of various stages of phylogeny and the most archaic componant of the family in SW.-S.China and adjacent region, which is the centers of modern distribution, differentiation and preservation, and therefore, the possible origin center of the family. The plants of Magnoliaceae must have originated in Jurassic and then diferentiate southward to tropical Asia and northward to Europe. The American Magnoliaceae must have been derived on the Euramerican landmass before the complete separation between NoAh America and Europe in the Tertiary period. The Magnoliaceae in South America might migrate from North America in Miocene or late.