VEGETATION OF THE NORTHEKN SHORES. 



179 



Astragalus canadensis L. (^Cosmop- 

 olite.) 

 Trifolium repens L. (Introduced ?) 

 Potentilla anserina L. 

 Mentha piperita L. (Introduced.) 



Galeopsis Tetrahit L. (Introduced.) 

 Physalis viscosa L. 



Blitum capitatum L. 



Amaranthus albus L. (Introduced.) 



Polygonum dumetorum. L. 



Corresponds to Astragalus glycipbyllos 



L. Equally cosmopolite. 

 Everywhere in Europe. 



Mentha piperita L. Everywhere in 

 Europe, especially in the plains. 



Everywhere in Europe. 



Corresponds to Physalis Alkekengi Zr., 

 cosmopolite like the Solaneae in 

 general, and all plants which at- 

 tach themselves to man. 



Blitum capitum L. In Wallis. 



The sands of Europe. 



Grows in Europe in diverse latitudes. 



From these various tables it is easy to see that the vegetation of the northern 

 shores of Lake Superior is perfectly similar to the subalpine vegetation of 

 Europe, at that zone which, in the Jura for instance, extends from 3,000 to 

 3,500 feet, and which in the Alps extends from 3,500 to 5,000 feet. Now 

 removing some plants of the lakes, and some few peculiar American types, 

 the subalpine flora remains in its integrity, and wUl be found to form chiefly 

 the vegetation about the northern shores of Lake Superior. 



SPECIAL COMPARISON. 



Distribution of the Trees and Shrubs of Switzerland from the Plains 

 to the Summit of the Mountains, compared with those of North 



America. ' 



As it is easier to perceive the regular order of succession of the 

 different growths which follow each other along the slope of a moun- 

 tain, and to determine under such circumstances the precise limits of 

 their distribution, than to ascertain the natural range of the corres- 

 ponding vegetation northwards over extensive tracts of land, in level 

 countries, I shall first introduce a general picture of the arbores- 

 cent vegetation of the Swiss mountains, before I undertake to show 

 that it agrees most minutely in its internal arrangement with that of 

 the lake districts. 



The vines which cover the margins of the Lake of Neuchatel, 1338 

 feet above the level of the sea, characterize, of course, the lower 



