Arthur: Cultures of Uredineae 



2J6 



77 



The three collections sent by Dr. Brenckle from Kulm, N. Dak., 

 bore out the prediction that he had based upon field observations. 

 One of the collections grew upon both Ambrosia and Carduus, 

 indicating that the races are not invariably fixed. The collection 

 sent by Mr. Bethel from Boulder, Colo., also bore out the predic- 

 tion which he had based on a field observation. No suggestions 

 came with the collection sent by Mr. Vasku from Nihill, Mont. 

 As stated in the North American Flora (7: 238. 1912), only 

 Carduus has heretofore been proven by cultures in this country to 

 be a host to this species, although both Ambrosia and Arnica have 

 been considered to be hosts, a conclusion derived from morpholog- 

 ical and field studies. 29 



10. Uromyces acuminatus Arth. A collection made by Air. 

 Bethel at Boulder, Colo., on Spartina Michauxiana, showing the 

 characteristic slender, acuminate teliospores to which this name 

 has been applied, was suspected from field observations to belong 

 to aecia found on Collomia. Sowings were made April 29 on 

 Collomia linearis. Stcironcma ciliatum and S. lanccolatum. In- 

 fection resulted only on Collomia, showing a great abundance of 

 pycnia May 8, and aecia May 12. 



This culture adds one more host experimentally proven to be- 

 long to this species, although it had been associated with the spe- 



2f> For previous cultures see Jour. Myc. 14: 12. 1908; Mycol. 2: 220. 

 1910; 4 : aa. 1912. 



