172 Fernald — Relationships of some American 
difference.” And in his summary of characteristics, he said: 
“The White Birch of Europe and the Canoe Birch resemble 
each other in their wood, their bark, and their ample propor- 
tions, which are perhaps superior in the American species. 
They differ in the form of their leaves, and they grow on very 
different soils: the Canoe Birch is exclusively attached to rich 
lands constantly cool, and capable of yielding an abundant har- 
vest of corn or of clover, and it propagates itself naturally only 
in that part of North America which corresponds in climate to 
the 54th and 55th degrees of latitude in Europe.” 
hese distinctions pointed out by Michaux are not, however, 
of such fundamental importance as to prove the American 
Canoe Birch (Betula papyrifera) organically distinct from the 
White Birch (B. ae L., B. pubescens, Ehrh.) of Europe. 
Michaux made no distinction in his Sylva between the true 
Betula alba and the smooth-leaved and smaller B. pendula, 
Roth. His plate was of the latter plant, which has more 
deltoid leaves than the true B. papyrifera, but is quite like 
another American tree soon to be discussed. The foliage of 
the true B. alba is, nevertheless, as will be seen on comparison 
of American and European material, so similar as to present no 
apparent distinctive feature. The Canoe Birch in its best de- 
