Eastern Asian-eastern North American phytogeographical relationships. A history from the time of Linnaeus to the twentieth century

The awareness and study of eastern North American-eastern Asian plant disjunctions is traced from the time of Linnaeus to the beginning of the twentieth century. Thomas Nuttall's previously overlooked contribution to this topic is discussed, and an annotated appendix of the taxa that he attributed to eastern Asia and North America is presented. Charles Darwin's influence on the thoughts and writings of Asa Gray is also discussed, based on published and unpublished letters and manuscripts in the Archives of the Gray Herbarium of Harvard University; the role that this correspondence played in the development of Gray's phytogeographical ideas and Darwin's theory of evolution is considered. A brief summary of the writings of Adolf Engler, and other nineteenth century botanists, pertaining to these disjunctions and their bearing on an understanding of vegetational patterns in the northern hemisphere is also given. The significance of the late nineteenth century explorations in China in making known the full extent of disjunctions between eastern Asia and North America has provided the basis for further work beyond the exploratory and theoretical stages of this fascinating pattern of plant disjunction.