424 MINNESOTA BOTANICAL STUDIES. 



mens of these were not left at the University herbarium. No 

 species however are reported by him, that have not been col- 

 lected by the staff of the survey. Mention of Seymour's collec- 

 tions is appended to each species reported by him. 



The nomenclature of Burrill * has been made use of in the 

 list and for full synonymy the reader is referred to the works 

 cited below. Britton and Brown's Illustrated Flora of the 

 United States and Canada has been closely followed in the 

 naming of all host plants. 



Of the Erysipheas, nineteen species in all have been col- 

 lected, distributed among the genera as follows : Spharotheca, 

 3 ; Erysiphe, 5 ; Uncinula, 3 ; Phyllactinia, i ; Podosphcera, 

 i ; Microsphara, 6. In field work carried on during such a 

 long period of time and by as many as ten collectors acting 

 independently, it is to be expected that the number of collec- 

 tions of common forms will be increased at the expense of the 

 number of species. A glance at the list given below will show 

 that such has been the case in Minnesota. There are undoubt- 

 edly at least a dozen more species of blights in the state, and 

 it is hoped that this list will aid future observations. In citing 

 the district of collection, only the county name is given. 



1. Sphaerotheca humuli (DC.) BURRELL, Bull. 111. St. Lab. 



Nat. Hist. 2 : 400. 1887. 

 On leaves of : 



Rubus hispidus L. : St. Louis, July, 1886, Holway 46. 



(JS. castagnei Lev.) 



Viola sp. indet. : Brown, July, 1891, Sheldon 851. 

 Humulus lupulus L. : ,f Sheldon 7020. 



2. Sphaerotheca castagnei LEV. Ann. Sci. Nat. III. 25: 139. 



1851. 

 On leaves of : 



Taraxacum taraxacum (L.) KARST. ; St. Louis (?) ; July, 

 1886, Holway 276. (Not published in Arthur's report.) 



* Burrill, T. J., and Earle, F. S. Parasitic Fungi of Illinois. Bull. 111. St. 

 Lab. Nat. Hist. 2. 1887. 



Ellis, J. B., and Everhart, B. M. North American Pyrenomycetes, 2-30. 

 1892. 



fMr. Sheldon's last field note book has not, up to the present time, been 

 found. Consequently the dates of collection, the district and the name of the 

 host plant often cannot be determined. The missing data are indicated as 

 above. 



