PLATE XIX 



Betula glandulosa (36a and 36b) and 



Betula occidentalis (37a and 37b) 



Vessels present; vessels commonly in radial multiples; often 

 spring wood vessels are closely spaced singles or in irregular 

 clusters (some appearing as subdivisions of a single vessel), 

 the vessels progressing toward formation of radial multiples 

 from early to late wood; vessel perforation plates scalariform; 

 rays both one and two cells in width . 



