284 
IOWA ACADEMY OF SCIENCE Vol. XXVIII, 1921 
^ ^ Leptomitaceae 
Leptomitus. lacteiis Ag. 
*“On decaying animal and vegetable matter in water”. (4). 
Pythiaceae 
Pythium de Baryamim Hesse. 
Attacks seedling plants and is called by gardeners “Damping Off.” (4). 
Albuginaceae 
Cystopus candidus (Per) Lev. 
“The white rust of crucifers”. (1). 
Brassica arvensis. Melhus; Clarion, June, 1907. Pammel; Ames, Au- 
gust, 1911. 
Brassica nigra (3). Bessey; Ames, July, 1880. 
Caipsella bursa-past oris (3) (6). Phode; Randolph. King; Ames, 1912. 
Anderson; Decatur County, May, 1904. Hitchcock; Ames. Pammel and 
Stewart. “No oospores have been found, lives through the winter within 
the tissues of the seedling host plants.” (2). “Confined to Cruciferae. 
lives over the winter within the tissue of seedling plants which spring 
up in autumn particularly in case of above host, which may account for 
the lack of formation of oospores” (10). 
*Lepidium apetalum (6). 
^Lepidium Virginicum (6). Anderson; Decatur County, May, 1904. 
Pammel ; Ames, September, 1890. 
Radicula armoracia. Anderson ; Decatur County, May, 1904. Pammel ; 
Ames, September, 1890. 
Radicula palustris. Bennett; Tripoli, July, 1912. Anderson; Decatur 
County, September, 1904. Fawcett; September, 1914. King; Ames, June, 
1914. 
^Radicula sessili flora (3). ' 
Raphanus sativus (3). Pammel; Waukon, July, 1908. Pammel; De- 
corah, July, 1908. Stewart; Ames, September, 1893. McPherson; Council 
Bluffs, 1895. Pammel ; Ames, September, 1900, September, 1901. Oos- 
pores abundant in inflorescence (6). 
Sisymbrium .canes cens. 
Sisymbrium officinale (10). Anderson; Decatur County, 1898. Hitch- 
cock ; Ames. 
Cystopus bliti (Bib) Dby. 
*Acnida cannabina (10). 
Acnida tamarisciiia (3). 
^Amaranthus sp. (1). 
'^Amaranthus graecizans (6). (10). 
Amaranthiis blitoides (10). Pammel; Ames, 1910. King; Ames, 1911. 
Amaranthus hybridus (3) (10). 
Amaranthus retro flexus (3), (10). Hitchcock; Ames. Pammel; Ames, 
1910. King; Ames, 1910. Raymond; Ames, 1891. Bessey; Ames, Sep- 
tember, 1882. Bessey; Ames, 1878. King; Ames, 1912. Pammel; Ames, 
September, 1902. Pammel; Ames, July, 1892; 
Montelia tamarisciiia. “On leaves of common beet, no oospores ob- 
served.” (5). 
Cystopus portulaceae (D. C.) Lev. 
“On purslane” (1). 
Portulaca oleraccae (3). Bessey; Ames, 1890. Raymond; Ames, 1891. 
Hitchcock; Ames. “Abundant on this host from middle of June to first 
of September. Oospores abundant,” (6). Halsted (10) reports it in 
1886 to be more prevalent than ever on the above host in spite of drought. 
He accounts for this in that the host itself is a low growing succulent 
plant containing considerable moisture. 
Cystopus ipomoeac-panduranae. (Lev). Farl. 
Ipomoea batatas (4). Pammel; 1892. Pammel & Clarke; Hamburg. 
July, 1914. 
