PLATE 27 



A. — A small canker caused b}?^ Cytospora chrysosperma on the trunk of a tree of 

 Populus italica, with the bark cut from around canker. 



B. — A tree of Populus widizeni on the streets of Albuquerque, N. Mex., dying 

 from the attacks of C. chrysosperma. 



C. — Main stem of a yoting tree of Populus italica killed by C. chrysosperma, showing 

 young sprouts at the base of the tree. 



D. — A branch of Populus wislizeni attacked by C. chrysosperma, showing the spore 

 horns of the fungus. 



(344) 



