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IOWA ACADEMY OF SCIENCE Vol. XXVIII, 1921 
Peronospora potentillae D,By. 
Agrimonia gryposepala. Melhus ; Ames, June, 1916. 
Potentilla monspeliensis (4), (8). Hitchcock; Ames. Anderson; De- 
catur County, May, 1904. .“On Potentilla sp. in autumn” (1). “Not 
found in 1895; local in 1894” (6). “Found only in one place, in shade of 
leaves of Potentilla monspeliensis'' (8). 
Peronospora euphorhiae Fckl. 
"^Euphorbia macnlata (4). 
^Euphorbia preslii. 
Euphorbia serpyllifolia (2). Hitchcock; Jewell Junction. “Is a species 
which quickly diminishes in time of drought. Not uncommon in Euphor- 
bia maculata in wet seasons. Scarce past two years. A new host, E, 
serpyllifolia was added last year by M[r. Hitchcock. (10). 
Peronospora Arthuri Farl. 
Oenothera biennis. Anderson; Decatur County, July, 1905. Melhus; 
Iowa City, July, 1916. 
Peronospora polygoni Thuem. 
Polygonum aviculare (4), (10). King; Ames, June, 1912. 
Polygonum scandens (4). “Is far from common on this host. Mr. 
Hitchcock in May, 1887, found a few specimens of it on P. aviculare, thus 
making a new host for Iowa.” (10). 
Peronospora lophanthi Farl. 
Agastache scrophulariaefolia (2), (10). Hitchcock; Ames. “Found for 
first time in this host in 1888.” (10). 
Peronospora alta Fckl. 
Plantago major (4), (10). Pammel ; Ames, June, 1909. June, 1910, 
June, 1917. “In 1^5 very common. Has been almost entirely absent 
from Plantago major for past year.” (10). 
Plantago Rugelii. Pammel; Ames, October, 1909. King; Ames, 1912. 
Peronospora hydrophylli Waite. 
Hydrophyllum Virginicum. • Pammel ; Ames, June, 1914. McGregor, 
May, 1918. “Reported by Hitchcock on this host at Iowa City in 1888” 
(13). 
Peronospora sparsa Berk. 
Rosa sp. Sioux City, .October, 1914. 
Peronospora alsinearum Caspary. 
Cerastium nutans (4). 
Peronospora urtica (Lib.) D. By. 
^Laportea canadensis (4). 
Peronospora calotheca D. By. 
^Galium aparine. Holway found oospores in the leaves and stems of 
this host at Decorah, June, 1884. (13). 
^Galium boreale (4). “Frequently met with on species of Galium. 
Not found this season until October 14, when it was collected in abundance 
upon seedling bed straws. This seems like a clear instance of fresh-grow- 
ing plants being favoraible for the development of PeronosporasP (10). 
Peronospora leptosperma D. By. 
“On wild sage” (1). 
^Artemisia biennis (4), (10). 
^Artemisia ludoviciana. Common in these last two hosts in 1895. 
Peronospora ficariae Tub 
^Ranunculus repens (4). 
Peronospora violae D. By. 
Viola sp. Knox; Primghar, August, 1911. 
Peronospora gonolobi Lagerh. 
Gonolobus laevis. Anderson; Decatur County, July, 1902. 
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