NATIVE GRASSES AND PUCCINIA GRAMINIS 191 



on the barberry. At Postville the writer found a single large clump 

 of wild barberry and several smaller ones on the farm of Mr. Orr, 

 a little distance out of the city of Postville. There was an abundance 

 of P. graminis on oats in the field nearby and on red top. Several 

 hedges of barberry occurred in the city of Postville and the pre- 

 sence of these accounted for the large amount of P. graminis along 

 the Chicago, Rock Island & Pacific Railway, on wild grasses like 

 red top, squirrel tail, quack grass and volunteer oats, and on wheat 

 near the elevator. 



At Clermont wild barberries occurred for half a mile along the 

 highway and in these places there was invariably considerable rust 

 on squirrel tail, red top and timothy as well as on oats. 



Early in July the writer examined the red top in the vicinity of 

 several hedges in the city of McGregor. Red top, which was the 

 most common grass in the vicinity, was badly rusted in every case. 

 Later in the season I examined the wild grasses in the vicinity of 

 the wild barberry. An abundance of rust was found on squirrel 

 tail grass and quack grass. In some cases the culms were covered 

 with the black pustules. , 



The Fonda and Pocahontas Cases — In response to a request from 

 I\Ir. O. B. Dunbier of Pocahontas, Iowa, I visited the place of Mr. 

 J. Jordan of Fonda, who had a hedge 266 feet long, facing two 

 streets and adjacent to fields of small grain. The barberries had been 

 planted in two rows ; in all there were about 500 separate clumps 

 with an average of 15 stalks to each clump, making all told about 

 7,500 stalks with about 1,125,000 leaves. As near as I could de- 

 termine, 5,000 leaves carrying secial spores or about 11,250,000 

 spores were produced by this hedge. Perhaps 50 per cent would 

 reach a favorable nidus for germination. There was certainly 

 enough material here to produce a rust epidemic. The oats in the 

 vicinity, according to testimony, were badly rusted. It is certain 

 that Hordeum juhatum, Agropyron SniitJiii, as w^ell as the Agro- 

 pyron tencrum growing on the highway were abundantly rusted. 



The writer also found in the city of Pocahontas a single large 

 clump of barberry and the orchard grass adjacent to it was infected 

 with Puccinia graminis. An abundance of this rust was found on 

 quack grass also. The same rust was found at Thorpe in the same 

 county, but whether it was associated with a barberry I am unable 

 to say. None of the barberry was observed. 



Hamilton, Illinois, Case — Another interesting case came under my 

 observation in Hamilton, Illinois. In going through the woods and 

 fields looking for rust, which was not much in evidence, I found in 



