60 SILVA OF NORTH AMERICA. BETULACE. 
west! northwestward to the coast of Alaska, along which it extends from the Lynn Canal? to the 
shores of Cook Inlet.2 It is the common Birch-tree of the Yukon basin, where it grows sparingly 
near the banks of streams in forests of coniferous trees and in large numbers on sunny slopes and 
hillsides.* 
In 1898 Betula Alaskana was introduced into the Arnold Arboretum from seeds gathered near 
Skaguay, Alaska. 
1In July, 1876, Betula Alaskana was collected at Prince Albert White Pass above Skaguay at the head of the Lynn Canal, Alaska, 
on the Saskatchewan in latitude 58° north by Mr. John Macoun. by W. M. Canby, John Muir, and C. S. Sargent. 
In 1887 it was found by Dr. George M. Dawson on the Dease 3 During the summer of 1897 Betula Alaskana was found by Mr. 
River and on the Lewis River “near the mountains.” W. H. Evans on the shores of Cook Inlet. 
2 In August, 1897, Betula Alaskana was found at the foot of the 4 Teste M. W. Gorman, in litt. : 
EXPLANATION OF THE PLATE. 
Puate DCCXXVI. Beruta ALASKANA. 
tle 
A flowering branch, natural size. 
. A staminate flower, enlarged. 
. A fruiting branch, natural size. 
2 
3. 
4. 
5. 
6. 
A scale of a fruiting ament, enlarged. 
. A nutlet, enlarged. 
. A winter branchlet, natural size. 
