PLATE I 



Taxus brevifolia (la and lb*) 



Vessels absent; tracheids with spiral thickenings. 



Juniperus communis (2a) and 

 Juniperus scopulorum (3a) 



Vessels absent; tracheids without spiral thickenings. 



Artemisia tridentata (4a and 4b) 



Vessels present, grouped in patterns forming concentric 

 bands; rays three to many cells in width, often massive, 

 dispersed between uniseriate rays; band of cork tissue 

 initiating each growth ring. 



