126 



ESS A YS. 



Eastern North American representatives, about 0.61 per 

 cent. ; of identical species, 0.23. 



So geographical continuity favors the extension of identical 

 species ; but still eastern North America has more in common 

 with Japan than western North America has. 



The relations of this kind between the floras of Japan and 

 of Europe are obvious enough ; and the identical species are 

 mostly such as extend continuously — as they readily may — 

 throughout Russian Asia, some few only to the eastern con- 

 fines of Europe, but most of them to its western borders. To 

 exhibit more distinctly the features of identity between the 

 floras of Japan and of North America, and also the manner 

 in which these are distributed between the eastern and west- 

 ern portions of our continent, — after excluding those spe- 

 cies which range around the world in the r orthern hemisphere, 

 or the greater part of it, or (which is nearly the same thing 

 in the present view) which are unknown in Europe, — I will 

 enumerate the remaining peculiar species which Japan pos- 

 sesses in common with America: — 



In Japan. 



Anemone Pennsylvanica 

 (Coptis asplenifolia ?) 

 (Trautvetteria palmata) 

 Caulophyllum thalic- 



troides 

 Diphylleia cymosa 

 Brasenia peltata 

 Geranium erianthum 

 Rhus Toxicodendron 

 Vitis Labrusca (Thunb.) 

 Thermopsis fabacea 

 Prunus Virginiana ? 

 Spiraea betulaifolia 

 Photinia arbutifolia, in 



Bonin. 

 Pyrus rivularis ? 

 Ribes laxiflorum 

 (Penthorum sedoides, 



China) 

 Cryptotsenia Canadensis 

 Heracleum lanatum 



In W. N. America. 



C. asplenifolia 

 T. palmata 



(B. peltata) 



G. erianthum 



R. Toxicodendron, var. 



T. fabacea 



S. betulaifolia 



P. arbutifolia 

 P. rivularis 

 R. laxiflorum 



H. lanatum 



In E. N. America. 

 A. Pennsylvanica 



T. palmata 



C. thalictroides 



D. cymosa 

 7\ peltata 



)i. 



In Toxicodendron 

 V. Labrusca 



P. Virginiana 

 S. betulaifolia 



P. sedoides 

 C. Canadensis 

 H. lanatum 



