138 Bulletin 313 



Cercospora medicaginis E. & E. — On the leaves of alfalfa, and 

 red and crimson clovers. Causes orbicular, more or less indefinite 

 smoky or black spots, 3-5 mm. in diameter on both surfaces of the 

 leaf. Conidiophores on both surfaces, crowded on upper surface, 

 subhyaline becoming yellowish-brown, septate, 35-45 x 4-5 fx ; conidia 

 cylindrical tapering, 3-8 septate, 40-60 x 3 /a. 



Note: Septa on conidia from clover fewer and farther apart. 



816. Infected alfalfa leaf. 817. Conidiophores, 1/12. 818. Conidia, 1/12. 

 819. Infected clover leaf. 820. Conidia, 1/12. 



Cercospora microsora Sacc. — On the leaves of the Hnden (Tilia 

 Americana) and other species of Tilia. Causes small, dark brown, 

 sub-orbicular spots with light centers, which sometimes are very 

 numerous and cover the greater part of the surface, Conidiophores 

 fasciculate from a tubercular stroma, short, non-septate, olivaceous, 

 almost hyaline at the tips 20-30 x 3 ju.; conidia filiform, obclavate 

 rnulti-septate, constricted at septa, olivaceous, 50-100 x 3.5 fi. 



821. Infected leaf of Tilia Europea. 822. Conidiophores, 1/12. 823- Conidia, 

 1/12. 



