Most comparisons of the temperate floras of eastern North America and eastern Asia have addressed the systematic or floristic level. Data on vegetation pattern and structure, when present, have been broadly descriptive, with little detail on gradient relations or intercommunity pattern. Great Smoky Mountains National Park, the largest eastern temperate preserve of floristic diversity in the United States, lies near the center of development of the North American deciduous forest. The flora of this park was used to model the gradient distributions and ecological characteristics of species with east Asian near-relatives. The disjunct taxa (162 species or 13 percent of the flora) were a highly nonrandom assortment of the native flora (total = 1,21 1 species) as a whole: they were more likely to be primitive in phylogenetic standing, perennial, and woody. They were also non-randomly distributed among habitats, being more likely to be found on exclusively terrestrial, forested, and mesic sites. Taxa belonging to genera absent from eastern Asia (232 species or 19 percent of the flora) were an equally interesting non-random sample of the native flora: they were more likely to be herbaceous and advanced in phylogenetic standing. Absent taxa, however, essentially represented a random sample of the flora as a whole in terms of degree of habitat openness and substrate type. When gradient distributions were corrected for overall species richness distributions, absent taxa showed their peak importance on xeric sites. Taxa in wide-ranging north temperate genera (817 species or 67 percent of the flora) generally constituted a random sample of the flora as a whole; they showed peak importance at higher elevations. These data are used to make inferences about the distribution of species richness in the Smokies landscape. Evidence that the eastern Asian temperate deciduous forests were the most diverse temperate forests on earth is also reviewed. Alternative hypotheses concerning the nature of this heightened diversity are discussed. Investigations of the floristic relationship between temperate eastern Asia and eastern North America generally have treated such relationships at the geographical, systematic, or evolutionary level. There are, however, important ecological correlates to this relationship that have gone, for the most part, untested. This investigation uses a well-known eastern North American landscape, the Great Smoky Mountains, to examine ecological correlates of the floristic relationship. Although others have qualitatively described many of these patterns (cf. Hu, 1936; Cain, 1943; Li, 1952; Wang, 1961), quantitative studies have been lacking. An objective of this research, then, was to develop explicit tests for the distribution of ecological properties in the flora as a function of phytogeography. The landscape distribution of the Great Smoky Mountains flora was used to develop and discuss community level hypotheses on the eastern AsianNorth American floristic relationship. NORTH TEMPERATE DISJUNCTION