436 GEOLOGICAL SURVEY OP CANADA. 



River, west through Ontario to the Manitoulin Islands of Lake Huron. 

 (Sargent} Abundant in Nova Scotia and New Brunswick. (Hooker.} 

 A common forest tree, New Brunswick. (Fowler's Cat.} An abundant 

 tree in Quebec and northern Ontario, but not extending west to Dog 

 Lake, north-east of Lake Superior. (E. Bell.} 



(1975.) B. lutea, Michx. f. Yellow Birch. 

 B. excelsa, Pursh, Fl. I., 621, not Alton. 



This is one of the finest trees of the Canadian forest, but does not 

 attain fhe same dimensions in Ontario as it seems to do in the eastern 

 provinces. (Macoun.} It extends from Newfoundland to Rainy River, 

 and ranges north of the height of land at Lake Abittibi, but is not found 

 on the north shore of Lake Superior, from Michipicoten to the United 

 States boundary, and only small trees are found on the Canadian side 

 of the line from this point to its western limit. (E. Bell.} Around 

 Lake Mistassini, North-east Territory. (J. M. Macoun.} 



(1976.) B. alba, var. populifolia, Spach. 



B. populifolia, Hook. Fl. II., 155. 



This tree is confined to the eastern provinces and St. Lawrence valley, 

 but its range is little known outside of New Brunswick. In Nova 

 Scotia, its size and peculiar habit at once attract the western botanist 

 only acquainted with its congener the Canoe Birch. Along the sea 

 coast it is not uncommon and the same may be said of it in New 

 Brunswick, where it is reported as being common. (Macoun} New 

 Brunswick and the valley of lower St. Lawrence River to the southern 

 shores of Lake Ontario. (Sargent.} 



(1977.) B. papyrifera, Michx. Canoe Birch. 



B. papyracea, Ait. Gray, Man. 459, 1868. Macoun's Cat. No. 1624. 

 B. occidentalis, Lyall in Jour. Linnsean Soc. VII., 134 (not Hooker.) 



No other tree in British North America has such a wide range as 

 this one, and if we include the western form, its limits are bounded by 

 the Atlantic on the east, by the Pacific on the west, extending south- 

 ward beyond our border, and on the north by the limit of deciduous trees. 

 (Macoun} Northern Newfoundland and Labrador, to the southern 

 shores of Hudson Bay and north-west to the Great Bear Lake and the 

 valley of the Youcon River, Alaska, (Sargent} The British Columbia 

 form has much shorter and thicker leaves and a very different bark, so 

 that it may be a distinct variety, and in that case should appear under 

 Lyall's name. 



