EUTHALLEPHYTA EUMYCETES RUSTS 



231 



Fig. 67. Clover Rust. Uromyces Trifolii. (Hedw.) Lev. 1. Aecidium spores; above, 

 two cluster cups in which the aecidiospores are found. 2. White clover leaf showing the 

 distortions produced by the aecidium stage. 3. Red clover leaf showing clusters of uredo 

 spores. 4. Uredo spores. 5. Teleuto spores. 6. An uredo cluster more magnified than 

 in 3. Figs. 1, 2, and 3 after Miss Howell. Remainder by Miss King. 



How long the fungus has affected clover plants in this country and especially 

 in Iowa is not known. 



Poisonous properties. Clover rust has been suspected of being injurious 

 to cattle. Dr. John R. Mohler of the Bureau of Animal Industry, writes as 

 follows with reference to mycotic stomatitis : 



Several attempts have been made by the writer to determine the exact cause and also 

 to transmit the disease to other animals by direct inoculation, but with negative results. 

 Suspicion, however, has been directed by various observers to the Uromyces and the red 

 and black rusts that occur in clovers. These fungi cause very severe irritation of the 

 lining membrane of the mouth, producing sometimes a catarrhal, at other times an aphthous^ 

 and occasionally an ulcerous stomatitis. 



Considerable irritation of the nose and throat is experienced when rusty 

 oats and wheat are threshed. Virchow records a case of severe inflammation 

 of the nose of an old lady in which he found a great deal of Puccinia graminis* 



