270 GRASSES OF IOWA. 



author states that the Puccinia graminis tritici occurs on cultiva- 

 ted varieties of wheat, Hordeum Jubatum, and H. vulgare. The 

 following spices also act as hosts: Triticum spelta, T. dicoccum, 

 Agropyron richardsoni, A. tenerum and Elymus canadensis. 



Eriksson and Henning and other writers* report this rust on 

 several o.her spzcies of Hordeum, Koeleria cristata, Lolium per- 

 enne, L. temulentum, Agropyron tenerum. 



The cluster cup fungus occurs more commDnly on the com- 

 mon barberry {Berber is vulgaris) bacause it is more commonly 

 cultivated. I have also found it on B cerasisforme and B. can- 

 adensis here at Ames. One species of barberry, B. thunbergi, is 

 exempt here. 



There is n^ evidence that the rust cm survive the winter in 

 the northera sta'es; i. e.: that the mycelium is perennial in the 

 tissues of wheat or grass. At least this does not occur in Iowa, 

 and Professors Hitchcock and Carleton failed to find that it is 

 perenniil in Kansas. They stite that it seems probable that 

 P. graminis does not pass the winter in this vicinity in the uredo 

 stage, n.rin the mycelial condition. Whether or not it sur- 

 vives the winter further south is a question still to be answered. 

 Eriksson and Henning state that in Stockholm and Sweden the 

 uredo spores do not persist during the winter, and that infec- 

 tion does not result from these occurring in the fall. Cold 

 weather is inimical to th:;ir development. The results of the 

 Swedish writ rs are entirely trustworthy. It is claimed by 

 Von Thumea for Austria, Plowright for England and Kuehn 

 for Germany that this species is perennial. In Austria accord- 



*Arthur, J. 0. Notes on Uredlneaj. Bot. Gaz. 16: 225. 1891 . 



BoUey. H. L. Wheat Rust. Bull. Ind. Agrl. Exp. Sta. 26: Wheat rust is the infec- 

 tion local or general. Agrl. Sci. 5: 259. 



Burrill, T. J. Parasitic fungi of Illinois. Bull, of the 111., State Lab. of Nat. Hist. 

 2: 141. 1885. 



Cobb, N. J. Contributions to an economic Icnowledge of Australian rusts. Agri' 

 Gaz. N. S. W., 1: 185. 3: 181. 



Carleton, M. A.. & Hitchcock, A. S. Preliminary report on rusts of grain. Bull. 

 Exp. Sta. Kansas Agri. OoU. Manhattan. 38: 1893. Cereal rusts of the IT. S. Div. Veg. 

 Phys. and Veg. Path. D. S. Dept. Agri. 16. 



Dietel, P. Uredlneen aus dem Himalaya. Hedwigia. 29: 259. 1890. 



Eriksson & Henning. Die Getreideroste. 



Farlow, W. G., & Seymour, A. B. A provisional Host index of the fungi of the 

 United States. 1888-1891. Cambridge. 



Lagerhelm, G. Oontr. a la Flore mycologique de Portugal, Bjlet. da Soc. Broterl- 

 ana. 8: 1890. 



Lugger, O. The black rust or summer rust. Bull. Minn. Agri. Exp. Sta. 64: 



Schroeter, J. Die Pilze in F. Cohn's Kryptogamenflora von Schlesien. Lief. 3, 

 188T-89. 



Sorauer, P. Handbuch der Pflanzenkrankheiten. Berlin. (2 ed.) 1886. 



Webber, Herbert, J. Catalogue of the flora of Nebraska, Nebr. State Board of 

 Agri. Lincoln. 1889: 



