223 



Uromyces polygoni (Per.) Fkl. Common. 

 On Polygonum aviciilare, 6, 1896. 



Uromyces trij'olii (A. t^ S. ) Wint. Rather common. 

 On Trifolium protense, 7, 1896. 



Uromyces tenbinthi (DC.) Wint. Very common. 

 On Rhus toxicodendron, 10, 1896. 



Besides these species a few additional host plants have been found, the most 

 interestino; and noteworthy of which is Polygonum dumetorum var. scandens. 



A number of species are common on Polygonum species, but in the past 

 season Puce. Convolvuli has been found upon this host in great abundance. The 

 rust occurs on the leaves, petioles, and occasionally on the stems in about the 

 same manner as it does on plants of Convolvulus. In fact, had I not been especially 

 fortunate in securing the host plant in bloom I should certainly have been led to 

 believe that I had found the rust upon some species of Convolvulus, as the foliage 

 and manner of growth of the two plants are very similar. 



Although there are some differences existing between the two forms of fungi, 

 I believe without a doubt they belong to the same species. 



Uredospores growing upon Polygonum dumetorum are not so uniform, and of a 

 much darker color than those on Convolvidus, while teleufospores upon the former 

 are slightly larger, more varied, with pedicles more deeply tinted, and sometimes 

 placed obliquely on the spore. 



The uredospores were collected the latter part of .June, and were not abund- 

 ant. Tne marked differences between these spores and uredo of authentic speci- 

 mens of Uromyces polygoni and Puccinia Polygoni amphibii led me to make further 

 search for material, and in the early part of the present month the teleutospores 

 of the above species were found in great abundance upon the same individual host 

 as the earlier stage. Host plants of the same species in various other localities of 

 the county were examined, but were not affected in the least with any rust. 



Dactylis glomerata (Puce, graminis). As far as I have been able to make out, 

 Puce, graminis has never been reported as growing upon this host, the usual species 

 found upon it being Puce, coronata Cda. Through the experiments of Eriksson, 

 he has found that, among other host plants, Puec. graminis will grow upon Dac- 

 tylis glomerata. 



The rust was found in the Experiment Station yard, appearing in linear sori, 

 and almost covering both sides of the leaves of the host. Although the grass 

 grew there in great abundance, only one or two tufts seemed to be infected with 

 the fungus. 



