KEY TO GENERA AND SPECIES 73 



ward and westward, also locally in eastern 

 Mass. (Figs. 123, 124, 125.) River Birch, 

 Red Birch, Betula nigra L. 



113. Papery bark white or whitish, rarely as dark 

 as bronze; in certain species not separating 

 spontaneously into filmy coils or fringes 

 114. 



Fig. 130. White Birch Fig. 131. Cordate-leaved 



Blue Birch. Birch. 



114. Leaves deeply cut, often into narrow divisions. 

 Cult. (Figs. 126, 129.) Cut-leaved Birch, 

 Betula pendula var. dalecarlica L. 



114. Leaves not deeply cut, distinctly triangular, 

 usually with a long tapering apex. Prince 

 Edwards Island to Md. (Figs. 127, 

 128.) Gray Birch, White Birch, Poverty 

 Birch, Old-field Birch, Betula populifolia 

 Marsh. 



114. Leaves neither deeply cut nor triangular 115. 



