300 GEOGRAPHICAL DISTRIBUTION OF PLANTS. 



Rubiace^e. — Cephalanthus occidentalis, button bush. This 

 shrub, which belongs to the sub-family of Cinchonece, occurs 

 in thickets of the Northern States and Canada, but does not 

 extend to Lake Superior. 



Composite. — Of this large family no shrub has been 

 detected in the canoe route north of Lake Superior ; though 

 the Crinitaria viscidiftora grows as high as the 55th parallel 

 on the banks of the Salmon River, west of the Rocky 

 Mountains, and on the upper branches of the Columbia above 

 the Kettle Falls. A small annual herb was found on the Sas- 

 katchewan, which Sir William Hooker placed next this species; 

 but, from the imperfect specimens, he could not ascertain its 

 genus satisfactorily. 



Vaccines. — Gaylussacia resinosa, black huckleberry, is 

 common in the Northern States westward to Wisconsin, and 

 extends northwards to the Saskatchewan. Vaccinium corym- 

 bosum, common swamp blueberry, extends from the Northern 

 States to Newfoundland and Canada, as far north as Quebec, 

 but has not been gathered to the westward of Lake Superior. 

 V. pe?insylvanicum, low shining-leaved blueberry, is very 

 common in the dry rocky woods of the Northern States, 

 Canada, and the country between Lakes Superior and Winipeg. 

 V. catiadense, downy-leaved blueberry, is the most abundant 

 species by the sides of streams and in thickets, from Maine and 

 Michigan to the shores of Hudson's Bay, and northwards in the 

 woody districts to the arctic circle. It extends also westward 

 across the mountains to the upper feeders of the Columbia. 

 V. idighiosnm, bog bilberry, occurs on the summits of the New 

 Hampshire Alps ; on the Green Mountains of Vermont, and 

 on Essex county mountains of New York ; on the Newfound- 

 land, Labrador, and Greenland coasts ; also from Lake Superior 

 northwards to the Arctic Sea. On the west side of the Rocky 

 Mountains it has been gathered on Sitka, Unalashka, andKot- 

 zebue Sound. In Europe it grows in the forests of the higher 

 Jura, in England, and the Scandinavian peninsula. Beyond 

 the arctic circle its fruit is not abundant every year ; but in 

 good seasons it is plentiful to an extraordinary degree, and is of 



