1920] A Little Known Vetch Disease 83 



Hab. parasitice in Vicia sativa, V. villosa, V. angustifolia et V. 

 dasycarpa. Amer. bor. 



An abundant supply of diseased material has been deposited in 

 the herbaria of the Missouri Botanical Garden and the Office of Myco- 

 log'ical Collections, Bureau of Plant Industry. 



In conclusion, the writer wishes to express his appreciation and 

 thanks to Dr. C. L. Shear, Bureau of Plant Industry, Washington, 

 D. C, and Dr. E. A. Burt, Missouri Botanical Gardens, St. Louis, 

 Mo., for their opinions and suggestions, given after examination of 

 material, as to the taxonomy of this interesting fungus. 



Summary 



A vetch disease previously little known has been under investiga- 

 tion during the past three years. 



It was first collected at Ithaca, New York, in 1907 and is now 

 known to occur also in North Carolina, South Carolina, Georgia, 

 Alabama, Mississippi, Louisiana and Tennessee. 



The disease is caused by Protocoronospora nigricans and since its 

 gross appearance suggests an anthracnose, it may be appropriately 

 called false anthracnose. 



Dark brown to black, elongated lesions may appear upon any of 

 the above-ground parts of the plant. Pod lesions are especially char- 

 acteristic since they are oblique to the margin of the pod. 



The disease is initiated in new fields by the planting of infected 

 seed. This is demonstrated by the occurrence of hyphae within the 

 seed and by the appearance of the disease on seedling plants in fields 

 not previously seeded to vetch. 



The fruit bodies of the parasite are subepidermal in origin and 

 possess setae, and a number of conidia are borne simultaneously at the 

 apices of the conidiophores. As these conidia fall away, new ones form 

 in their places. The conidia germinate in a yeast-like fashion, by sep- 

 tation and the formation of germ tubes, by developing a thickened, 

 short mycelium from which conidia are budded, and by the formation 

 of appresoria from which the infection tubes arise. 



It has not been possible to develop an ascigerous stage either in 

 culture or upon affected plant parts kept out of doors. 



All parts of the organism are multinucleate and primarily for this 

 reason, it is not believed to be related to Corticium, a thelephoraceous 

 fungus. It is believed to be more nearly like Colletotrichum, one of 



