PLATE XVII 



Salix scouleriana (33a, 33b, and 33c*) 



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 simple; rays 

 composed of both procumbent and upright cells; rays uniseriate 

 only. 



Populus trichocarpa (32c*) 



(See page 38) 



