IOWA ACADEMY OF SCIENCE 
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On Yituse vulpina L. 
Probably the most abundant species of the genus, growing especially lux- 
uriantly on the common wild grape, all the green parts of which are affected. 
Upright shoots, much enlarge and bearing smaller fleshy leaves, both leaf and 
shoot densely covered with the fungus are not uncommon on trailing vines. 
16. Plasmopaea pygmaea (Unger) Schroeter. [Peronospora pygmaea Unger.] 
On Anemone eanaclensis L., A. caroliniana Walt., A. qtoinquefolia L., and 
Hepatica acutiloda DC. (H. acuta Britt.) 
Very abundant from early spring to midsummer, often associated with other 
fungi on Anemone quinquefoUa. 
17. Peeoxospoea ALTA Fuckel. 
On Plantago major L. 
Not abundant, appearing in midsummer. 
18. Peeoxospoea Arthki Farlow. 
On Oenothera hiennis L. (Onagra Scop.) 
First seen July 16, 1909, and abundant from then until frost. Practically 
every leaf of many fully developed plants were severely infected throughout the 
region about Payette, but no infected rosetts were seen. 
19. Peronospora calotheca de Bary. 
On Galium horeale L. 
So far as observed this species was conflned to a few clumps of the host 
which grew in the open along the railroad, but in these localities the species 
was quite abundant in the early summer. 
20. Peronospora Chenopodii Schlecht. 
On Chenopodium album L., and G. Tiybridum L. 
Not uncommon throughout the later summer. The present species has been 
confused with P. effusa from which it is quite distinct. The relationship of 
these species has been discussed elsewhere so that it is unnecessary to enter 
into details here. 
21. Peronospora Echinospeemi Swingle. 
On Lappula virginiana (L.) Greene. 
While searching in early October for the perithecia of a powdery mildew 
two leaves were found infected with the present species. The collection is of 
more than ordinary interest as this is the most eastern station for the species, 
not to mention the fact that it has heretofore been collected only on narrow 
leaved hosts of the type of L. Redowskiana. 
22. Peronospora effusa (Grev.) Rabenh. 
On Chenopodium album L. 
Abundant throughout the summer and autumn months. 
23. Peronospora Euphoebiae Fuckel. 
On Euphorbia maeulata L. 
