NATIVE GRASSES AND PUCCINIA GRAMINIS 183 



Jackson^'' has since added some additional hosts, the Agrosfis liyc- 

 nialis. 



Agrostis pcrennans, Elymus striatits. It is a significant fact that 

 in my field work this rust was invariably common in places in prox- 

 imity to patches of Impatiens aurca or /. fidva, as at Pocahontas, 

 Spirit Lake, Thompson, Garner and Forest City. The timothy in- 

 fested host of this rust was found in proximity to Elymus and also 

 to Impatiens a urea. The teleuto spores have a tendency to produce 

 one or more crowns, as figured by us and Mr. Hume. It has some 

 resemblance to P. coronata. These field observations are referred to 

 here because they show the complexity of the problem before us. 



Elymus virginicus L. A widely distributed grass throughout the 

 region embraced in this paper, usually found in low grounds from 

 Missouri and Illinois to Wisconsin and South Dakota and Nebraska. 

 Puccinia graminis has been recorded for this grass but it was not 

 observed by me although I looked for it carefully at Burlington, 

 Ottumwa, Clinton, McGregor, Postville, Lake Mills, Thompson, 

 Forest City, Garner, Northwood, Dubuque, Rock Rapids, Little Rock, 

 Spirit Lake, Sibley, Sioux City, Hamburg and Council Blufifs in 

 Iowa ; at Sioux Falls, Mitchell and Brookings, South Dakota ; at 

 Luverne, Granite Falls, Albert Lea, Minnesota; at La Crosse, Wis- 

 consin, and at La Salle, Galena, Walnut, Hamilton and Zearing, 

 Illinois. I am inclined to think that this grass is not a factor in stem 

 rust of grains in this region. 



Elymus hrachystachys Scribner and Ball. The short spiked rye 

 grass on which P. graminis has been reported occurs from Michigan 

 to Texas, west to Nebraska and South Dakota. It is not uncommon 

 in the region. In Iowa it has been found at Sioux City, Hawarden, 

 Dakota City, Elmore, Rock Rapids ; also from Sioux Falls, South 

 Dakota. Puccinia graminis has not been found on the grass by the 

 writer. It must be rare on this grass. Several other species of 

 Elymus occur in the region. The fact that P. graminis has been re- 

 ported on five species of Elymus occurring in the region would lead 

 one to believe that the rust may occur on other species. Of the 

 other species the most common are E. striatns and E. Arkansanus, 

 which are more closely related to E. Macounii than E. virginicus, E. 

 canadensis and E. rohustus, on which P. graminis had been reported. 

 The aspect and texture of leaf and stem of E. Macounii approach' 

 those of Hordcum which may make it easier of infection. Field 



I'Bot. Gazette 35: 18. 



Proc. Ind. Acad. Sci. 1915 : 452. See also Uredinales of Indiana 



Proc. Tnd. 1917 : 345, reported under Puccinia Impatientis (Schw) Arth. 



