140 Bulletin 313 



Cercospor.\ obesa E. & E. — On the leaves of the thistle. Causes 

 irregular, grayish-brown, usually confluent leaf-spots, 2-5 mm. in 

 diameter. Conidiophores short, closely fasciculate, wavy, brown, 1- 

 septate ; conidia long, tapering, smoky, 2-7 septate, 50-60 x 5-6 ,u. 



Note: the original description probably written from examination 

 of immature material. 



824. Conidiophores, 1/12. 825. Conidia, 1/12. 



Cercospora rosicola Pass. — On the leaves of both wild and culti- 

 vated roses. Causes brown spots about 2-3 mm. in diameter sur- 

 rotmded by broad reddish border. Conidiophores in dense tufts, 

 brown, somewhat waxy, tips irregular, 20-40 x 3-5 /x. Conidia cylin- 

 drical, straight or slightly curved, both ends pointed, smoke-colored, 

 1-4 septate, 30-50 x 3.5-5 /x. 



826. Infected rose leaf. 827. Conidiophores, 1/12. 828- Conidia, 1/12. 



Cercospora reseda Fcl. — On the leaves of mignonette. Causes 

 small, yellowish gray, circular or irregular spots, frequently coales- 

 cing and causing a shrivelling. Conidiophores fasciculate, simple or 

 slightly branched, few or non-septate, light brown becoming reddish- 

 brown, 30-80 X 5 /x; conidia obclavate, 4-10 septate, 100-140 x 2.5-3 yx. 



829. Infected plant of mignonette. 830. Conidiophores, 1/12. 831. Conidia, 

 1/12. 



Cercospora rhuina C. & E. — On the leaves of the sumac {Rhus 

 copallina and R. glabra). Causes irregular brown spots with dark, 

 narrow, raised border. Conidiophores fasciculate, brown, usually 1- 

 septate, 2-4 mm. ; conidia long, tapering, brownish-tinged, 1-4 (occa- 

 sionally more) septate, 40-70 x 3 /x. 



Note: C. rhoina as given in Saccardo is probably a typographical 

 error. 



832. Infected leaflet of Rhus glabra. 833. Conidiophores, 1/12. 854. Coni- 

 dia, 1/12. 835. Conidiophore from R. copallina, 1/12. S36. Conidia from 

 same, 1/12. 



