The Cathaysian flora is characterized by the primitive taxa

numerous endmic genera and families and the complete taxa of the different stages of the systematic development of the flowering plants.There are closely conjuncition existed between the Cathaysian flora and the floras of Australian

African

South American

North American and European

as well as of the Malesian

Indian and Japanese floras.The conjunction went back to the earlier era of the Mesozoic Period.Before the Pangaea was discreted

the primary flowering plants appeared on the Pangaea

after the continental drifted

the flowering plants developed on the new circumstances continually.The disjuncted distribution phenomenon does not only exist between East Asia and North American but also exist between East Asia and all the other continents of the world.