188 Prof. Gray on the Botany of Japan, 
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 oatifande of Euro 
but most of them to its western borders. To exhibit more dis- 
tinctly the features of identity between the floras of Japan and of 
North America, and also the manner in which these are distrib- 
(rhioh is scent the same ee in the present view), whic ‘are 
unknown in Europe,—I will enumerate the remaining peculiar 
species which Japan possesses in common with America :— 
In W.N. America. In E. N. America. 
one Pennsylvanica A. Pennsylvanica 
(Coptis a eaposibolia one C. asplenifolia 
(Trautvetteria palm T. palmata T. palmata 
Caulophyllum Dhaticerciden C. thalictroides 
Diphylleia cymosa : 
Brasenia peltata [B, peltata] B. peltata 
Geranium erianthum ~ G. erianthum 
Rhns Toxicodendron R. Toxicod., var. R. Toxicodendron 
Vitis Labrusca (Thunb.) abrusca 
Thermopsis fabacea T. fabacea 
Prunus Virginiana ? P. Virginiana 
Spirea betulzefolia 8. betulzfolia 8. betulzefolia 
Photinia arbutifolia, in Bonin. P. arbutifolia 
Pyrus rivularis ? P. rivularis 
Ribes laxiflorum R, laxiflorum 
(Penthorum sedoides, oe P. sedoides 
Cryptotenia Canaden C. Canadensis 
Heracleum lanatum H. lanatum H. lanatum 
(Archemora rigida ? . Tigida 
(Archangelica Gmelini) A. Gmelini A. Gmelini 
Cymopterus littoralis ? C, littoralis 
Osmorrhiza longistylis O. longistylis O. longistylis 
Echinopanax horridus E. horridus 
Aralia quinquefolia A. om a 
Cornus Canadensis C, Canadensis CC. Citas 
Viburnum plicatum Vv. ern o esiae 
* Achillea Sibirica *A. Sibirica 
