PLATE 1 
Pucdnia graminis poae on congenial host plants, and photomicrographs of the 
different spore forms (all photomicrographs x 500). 
A. —Heavily rusted Poa compressa from the field; the rust is in the telial stage. 
B. —Teliospores from A. 
C. —Aecia on Berberis vulgaris resulting from artificial inoculation in the green¬ 
house; note the long aecial cups. 
D. —Aeciospores from C. 
E. —Poa compressa heavily infected with the uredinial stage as a result of 
artificial inoculation with urediniospores in the greenhouse. 
F. —Urediniospores from E. 
