PLATE 56 
A young pinon tree (Pinus edulis) diseased with. Peridermium occidental# in the 
pycnial stage, natural infection. Transferred from the forest near Mancos, Colo., to 
a pot in the greenhouse at Washington, D. C. The top has been killed by the fungus, 
giving it a spindle form, such as does not occur in trees fully alive. 
