SV 



Arthur: Cultures of Uredineae in 1913 *. 133 



kind sent the writer by Mr. Bethel was dated Sept. 17, 1910, and 

 was intended for cultures on Thalictrum. This could not be 

 made to germinate when time for culture work arrived, nor could 

 a half dozen other collections sent subsequently at various dates. 

 With a specimen dated April 5, 1912, Mr. Bethel states that he 

 has "proven by most positive field cultures" that it goes to 

 Thalictrum Fendleri. Again in May, 191 5, Mr. Bethel sent fine 

 materia! from his garden, showing the telia that had been brought 

 there anri the aecia on Thalictrum derived therefrom. The rea- 

 sons for listing the Thalictrum form under P. Agropyri were 

 stated in the last report. 12 The aecia are especially large and 

 prominent in this particular race on Festuca, as shown by a num- 

 ber of collections sent from the same locality. 



5. Puccinia Asperifolii (Pers.) Wettst. Two plants of An- 

 chiisa officinalis L. were given ample space in the experimental 

 garden of the Indiana Experiment Station and attained a fine de- 

 velopment, each plant measuring five or six feet across. On July 

 2, the weather being especially damp with occasional light showers, 

 steins of rye, heavily infested with rust, were laid upon the two 

 plants in the garden, doubtless a hundred or more stems to each 

 plant. The plants were not covered in any manner. The date of 

 the appearance of the first pycnia was not recorded, but on July 

 13, the plants were conspicuously dotted with yellow spots bear- 

 ing groups of pycnia. About a week later careful search brought 

 to light two groups of aecia. Although the vigor of the plants 

 and the condition of the weather seemed favorable, and the great 

 numbers of yellow spots with their groups of pycnia continued to 

 show, yet no further development of the rust took place. 13 



The reason why the infection should have started out with such 

 marked vigor and yet failed to mature aecia is not at all apparent. 

 The weather for the whole period was favorable for aecial growth. 

 It is possible, and yet scarcely probable, that the explanation lies 

 in the lessened vigor for the American rye rust, which is propa- 

 gated by repeating spores alone, the aecial hosts being practically 

 wanting in America. 



12 Mycol. 7 : 74. 1915. 



13 For a previous culture of similar character see Mycol. 1 : 236. 1909. 



