NOTES ON PARASITIC FUNGI IN WISCONSIN—IX 
J. J. Davis 
The greater part of the field work in 1920 was done along the 
lower Wisconsin and the Mississippi river, the Chippewa and its 
tributaries, the Yellow, the Fisher, and the Jump rivers. The sea¬ 
son was an unfavorable one because of low precipitation, which 
however allowed an unusual proportion of working days. 
Plasmopara acalyphae Wilson previously known only from the 
type station at Madison was found in July 1920 at Caryville in 
the Chippewa valley. As usual the development of conidiophores 
was scanty. [Collected since at Lone Rock, Arena and Oconto but 
always scanty.] 
Plasmopara ohducens Schroet. in summer is sometimes confined 
to small angular leaf areas which become brown, thus causing spot¬ 
ting of the affected leaves. The summer development of this mil¬ 
dew is more common northward. 
What is presumed to be mycelium and conidia of Sphaerotheca 
humuli (DC.) Burr, is sometimes abundant on leaves of Bubus 
allegheniensis at Madison during the early part of the season, dis¬ 
appearing in summer without development of perithecia. It has 
been noticed that the thickened leaves of the plants bearing Caeoma 
are especially liable to this infection. 
In a collection on twigs and young leaves of Physocarpus opuli- 
folius from Fish Creek referred to Sphaerotheca humuli (DC.) 
Burr, the perithecia bear long tapering appendages like those of 
Podosphaera leucotricha (E. & B.) Salmon in addition to short 
rhizoid basal ones. These long appendages are not apical, however, 
but basal or equatorial, and the spores are not crowded in the 
ascus. Nevertheless the Sphaerotheca would appear to be the 
‘^next of kin^’ to the apple mildew. The mildew on Physocarpus 
appears to over winter in the twigs or buds. 
Phyllachora oryzopsidis Theiss. & Syd. has been collected on 
Oryzopsis asperifolia at Mosinee. The collection was made in 
