RYDBERG: PHYTOGEOGRAPHICAL NOTES 95 
Tofieldia palustris. This is found in Great Britain, Scandinavia, 
northern Russia, the Alps, the Pyrenees and the Ural. Notwith- 
standing the fact that it is less distinctly arctic-alpine than for 
instance Lloydia serotina and has been collected in the lowland as far 
south as Two Harbors, Minnesota, it has not been collected in 
the Rockies south of northern Montana. 
ASIATIC ARCTIC-ALPINE OR GLACIAL PLANTS 
Dasystephana glauca is a distinctly Asiatic glacial plant, but 
also found in western North America, coming down south as far 
as Montana. 
AMERICAN ARCTIC-ALPINE OR GLACIAL PLANTS 
A large number of the alpine plants of the Rockies are strictly 
American glacial plants, i. e., found both in the mountains and 
the arctic regions of this continent but not in the mountains of 
the Old World. 
1. In many cases they are there represented by closely related 
plants. In such cases the history of the plant might be the follow- 
ing: 
(a) That the parent plant had a circumpolar distribution 
before or during the earlier part of the glacial period and the two 
telated species developed independently from it; 
(b) That the Old World plant existed on both continents during 
the glacial epoch and became modified after isolation on this 
side; or 
(c) That the American plant existed and became modified 
abroad. 
Here I give a list of such plants and the nearest relatives in the 
Old World. 
AMERICAN EUROPEAN ASIATIC 
*Calamagrostis purpurascens __C. arundinacea 
Salix glaucops TS. glauca 
Salix chlorophylla S. phyllicifolia 
*Alsinopsis propinqua A. verna 
+ Salix glauca and Rhodiola rosea are also found in northeastern America, but 
not in the Rockies. 
