﻿1903] CULTURES OF UREDINEAE 19 



est abundance, frequently affecting the leaves and stems of 

 nearly every plant in a large area where the host may be grow- 

 ing thickly. Such a group of plants has been under observation 

 for a number of seasons. In a space some twenty feet across, 

 protected by a group of willows, many hundreds of Impaticns 

 aurea Muhl. have sprung up from seeds each succeeding spring, 

 and when from six inches to a foot high have become remarka- 

 bly infested with aecidia. A rather large number of grass and 

 sedge rusts occur in the vicinity of this spot, and the teleuto- 

 spores of these have been sown in succession on Impatiens, and 

 invariably with no infection. It was not until well into June of 

 the present year that any clue was obtained. A tuft of Elymtis 

 virginicus L., growing at the edge of this patch of infested Impa- 

 tiens, was found to possess young sori of some uredo. Search- 

 ing further, dead leaves of the previous season were obtained 

 bearing inconspicuous sori of what has generally been called 

 Pticcinia ritbigo^vera, the teleutospores of which had already ger- 

 minated. A collection on the same host was in the laboratory, 

 however, that had been obtained early in the season from a local- 

 ity some miles distant, which was still in germinating condition, 

 Teleutospores from this were sown on Impatiens aurea, June 10, 

 spermogonia following abundantly June 17, and aecidia June 

 25. Spores from the same collection had been sown previously 

 on Ambrosia trifida and Napaea dioica, with no infection. 



There are other creditable species of Puccinia on Elymus in 

 the Rocky mountain and Pacific states, but this is the most com- 

 mon species and possibly the only one in the eastern states. 

 It should be called Puccinia Impatientis (Schw.), nom. nov. 



4- Puccinia subnitens Diet. — I am indebted to Rev. J. M. 

 Bates, of Callaway, Nebraska, for material to make the cultural 

 study of this species, and for the suggestion which made the 

 study fruitful. He wrote that wherever the grass rust occurred 

 he had observed an aecidium on Chenopodium leptophyllnm (Moq.) 



Nutt. 



Teleutospores from Distichlis spicata (L.) Greene were sown 

 on Chenopodium albumin, on May 24, and on May 31 spermogonia 

 appeared in the p-reatest luxuriance, followed bv aecidia on June 



