264 GRASSES OP IOWA. 



The following outlines show the chief cereal rusts and their 

 host plants: 



Maize {Zea mays), Puccinia sorghi, Schw. 



W\iQ?kt{Triticum vulgare), Puccinia graminis, Pers. f. tritici. 



Puccinia glumarum (^chxnidi) Eriks. 



& Henn. f. tritici. 

 Puccinia rubigo-vera (D. C.)Wint. 



f. tritici. 

 Puccinia dispersa, Eriks. & Henn. 

 Oats {Avena saliva), Puccinia coronifera, Klebahn. 



Puccinia cor on a ta. 

 Puccinia graniinis. f. avence. 

 Barley {Hordeum vulgare), Puccinia graminis. 



Puccinia simplex, Koernicke. 

 Puccinia glumarum. f. hordei. 

 Rye {Secole cereale), Puccinia graminis. f. secalis. 



Puccinia glumarum. f. secalis. 

 Puccinia rubigo-vera. f. secalis. 

 Eriksson and Henning use the name P. dispersa for the old 

 rubigo-vera, which has been in use among mycologists for a 

 long time. Carleton, after having made a careful morphologi- 

 cal study of the rusts of northern Europe and the Ucited States, 

 concludes that the P. dispersa and P. ruhigo vera are identical, 

 and that the name P. I'ubigo-vera should be used. He concludes 

 that we have six cereal rusts and a possible seventh in the 

 United States. 



CORN RUST. 



Corn rust {Puccinia sorghi, Schw.) Schweinitz,* an early 

 American mycological writer, described this fungus as early 

 as 1834, but earlier than this Carradori f an Italian writer, 

 referred to this fungus. It is widely distributed, occurring 

 where corn is cultivated, and at times is quite troublesome, 

 especially in North America. According to Saccardo, | it 

 occurs in Italy, Prance, Austria, Germany, Lusitania, North 

 and South America. Peck§ and Seymour || have given us the 

 only early economic accounts of the fungus. There is a^so a 



•Synop. Fung. 295. 



■tGiorn Fls. Pavla. 8. 1815. 



*Syn. Fnvg. 7: 659. 



§Rep, St. Mus. of Nat. Hist. N. Y.. 34: 29. 



IIU. S. Dept. Agrl. Report. 1887: 389. 



