174 IOWA ACADEMY OF SCIENCE Vol. XXVI, 1919 



perhaps most frequently in experimental plots. The B ramus puini- 

 lus on which the rust has been found does not occur in this region as 

 do B. ciliatus, B. Kalmii, B. purgans, B. marg'matus and the intro- 

 duced B. inermis, which is the most common of all the bromes in 

 western Minnesota and eastern South Dakota. But not in a single in- 

 stance, though the grass was growing in proximity to the barberry 

 and near infested grasses of Elymus robiistus, Hordenm juhatum, 

 Agropyron Smithii, A. rcpcns and A. tcnermn, did P. graminis 

 occur. The other perennial species were also free from P. graminis. 



Hordeae 



Agropyron Smithii Rydb. This grass is a native of the Missouri 

 drainage basin from southwestern Iowa, along Missouri river, ex- 

 tending northwestward through Carroll, Ida, Humboldt, Kossuth, 

 Hancock and Cerro Gordo counties, especially in northwestern Iowa, 

 where it forms a part of the native sod, westward through Neb- 

 raska northward to the Dakotas and Minnesota. It has become 

 naturalized along the right of way of railroads in almost every 

 county in Iowa, from Keokuk, Iowa, to La Crosse, Wisconsin , 

 Iracy, Ortonville and Graceville, Minnesota ; Walnut, Hamilton, 

 Zearing and La Salle, Illinois. Puccinia graminis was common at 

 Humboldt, Fonda, Pocahontas, Sibley, Spirit Lake, Rock Rapids, 

 Forest City, Luverne, Algona, Corwith, Northwood and Garner, 

 Iowa. It was also common at Graceville, Tracy, Marshall, Orton- 

 ville, Albert Lea, Minnesota; Mitchell, Watertown, Brookings, Mill- 

 bank and Sioux Falls, South Dakota. In many of these places the 

 plants were in proximity to barberry hedges. 



Agropyron psuedo-repens Scribner and J. G. Smith. This species 

 has been united with A. tcncriim by A. S. Hitchcock. It is not com- 

 mon in the region. It occurs in northwestern (Lyon county) Iowa 

 and adjacent parts of South Dakota, as at Sioux Falls and Mitchell. 

 P. graminis occurs on this grass but not as abundantly as on the 

 A. teneriim or A. rcpcns or A. Smithii. It is not an important fac- 

 tor in rust. , 



Agropyron tcncrum Vasey. Slender wheat grass is widely dis- 

 tributed and common in eastern South Dakota, as near Mitchell, 

 Watertown, Brookings. Sioux Falls; in southern Minnesota, at 

 Graceville, Ortonville, (jranite Falls, Worthington and Albert Lea; 

 in Iowa at Rock Rapids, Little Jiock, Thompson, Sibley, Spirit 

 Lake, Lake Park, Forest City, Lake Mills, Garner, Britt, Humboldt, 

 Havelock, Marathon and Armstrong. It is a native in Iowa, es- 

 pecially west of Mason City. 



