Arthur: Cultures of Uredineae in 1909 



221 



considered to be the same as the one in Europe from which it 

 takes its name. The experiments of Fuckel, Plowright, and E. 

 Fischer have shown that the European form produces aecia on 

 Pulicaria dysenterica, and the failure of the American form to 

 do so may mean that the two are distinct species, or that there 

 are physiological races on different hosts. Further studies are 

 necessary to decide the question. 



14. Uromyces acuminatus Arth., on Spartina cynosuroidcs 

 Willd., collected at Fayette, Iowa, by Prof. Guy West Wilson, 

 was sown on Stcironcnia ciliatum, S. lanceolatum and Pole- 

 moniiini reptaiis, with no infection. Similar material from north- 

 ern Indiana has been sown in previous years on six other hosts, 

 and also four times on Stcironcnia ciliatum and two times on 5. 

 lanceolatum, without infection. 



Some years ago in a morphological study of all collections of 

 Uromyces on Spartina then available the writer decided^^ that 

 the form from the salt marshes of the Atlantic coast, known 

 under the name U. Spartinae Farl., having somewhat larger telio- 

 spores and urediniospores, the former with more rounded apices, 

 and the latter with thicker walls, than the western form mentioned 

 above, occurred also in the interior of the continent, and could 

 not be clearly separated from U. acuminatus. Recently my 

 associate, Mr. F. D. Kern, has restudied the two forms, with all 

 the data that have accumulated in the decade since my own study 

 was completed, and is able to supplement the morphological 

 differences which I pointed out with others, and concludes that 

 the two forms represent distinct species. He gives the distri- 

 bution of U. acuminatus as the wet, alluvial prairies of Iowa, 

 Minnesota, and adjoining states, extending eastward to northern 

 Indiana, while U. Spartinae is found in saline soils from Alberta 

 southwestward to Wisconsin and Kansas, and along the Atlantic 

 coast from Nova Scotia to Florida. Reexamining the successful 

 cultures with Uromyces on Spartina, made in 1905 and 1907, the 

 material for which was sent from western Nebraska,^- it is 

 found that the culture material agrees with U. Spartinae Farl. 

 Putting all the data together, the writer's suspicions, recorded 



See Jour. Myc. lo : 9. 1904; 13: 193. 1907. 

 Bot. Gaz. 34: 3. 1902. 

 ^-Jour. Myc. 12: 24. 1906; and 14: 17. 1908. 



