Davis — Parasitic Fungi in Wisconsin — II. 93 



NOTES ON PARASITIC FUNGI IN WISCONSIN— II. 



J. J. Davis. 



This communication holds a supplementary relation to A pro- 

 visional List of parasitic Fungi in Wisconsin which was pre- 

 sented to the Wisconsin Academy of Sciences, Arts and Letters 

 in March, 1912, and published in its Transactions, volume 

 XVII pt. 2. After some notes of a miscellaneous character a 

 list is given of hosts and another of species additional to those 

 previously reported for Wisconsin. A communication of simi- 

 lar scope was presented to the Academy in April, 1913, and is 

 published herewith. 



University of Wisconsin Herbarium, Madison, Wisconsin, 

 April, 1914. 



Peronospora viciae (Berk.) D. By. In the provisional list a 

 question mark was placed after Vicia americana where given as 

 a host of this mildew. The reason for this is that the conidia of 

 the downy mildew collected on this host in Wisconsin are longer 

 than those of P. viciae on Pisum or on foreign species of Vicia 

 as far as I have examined them. All of the specimens on 

 native species of Vicia I have seen are similar to those that 

 have been collected on V. americana in Wisconsin. 'The Wiscon- 

 sin station is near Lake Mills and on the railroad right of way 

 where the mildew may have been introduced from the plains re- 

 gion which seems to be the habitat of this form. Such evidence 

 as I have seen indicates that the American and European forms 

 are physiologically distinct. I would suggest that tne native 

 form be distinguished as Peronospora viciae var. americana — 

 with conidia 30(24-36) x 20(17-26) and that Fungi Columbi- 

 ana 1836 on Vicia linearis Stockton, Kansas, Bartholomew, be 

 taken as the type of this variety. 



