PLATE XXIX 



Shepherdia canadensis (54a and 54b) 



Vessels present; vessels solitary, in pairs, or in various 

 aggregates; vessels tend to form concentric bands within the 

 growth ring; vessels relatively few and large; vessel walls 

 composed of five or six facets, giving the vessel a definitely 

 angular appearance; vessels grade into smaller sizes as the 

 growing season progresses without an abrupt change in size; 

 vessel perforation plates simple; axial parenchyma absent or 

 sparse, diffuse; rays one or two cells in width (rarely three). 



Pachistima myrsinites (55a and 55b) 



Vessels present; vessels solitary, in pairs, or in various 

 aggregates; vessels grade into smaller sizes as the growing 

 season progresses without an abrupt change in size; vessels 

 diffuse; perforation plate simple; axial parenchyma distributed 

 as an occasional single cell adjacent to a vessel; rays one or 

 two cells wide (rarely three) . 



