IOWA ACADEMY OF SCIENCE 
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On Celtis accidentalis L., on the distortions caused by the Phytoptus. Ames, 
Jan., 1889 (Halsted). 
This was distributed as No. 2336 of Ellis & Everhart’s North American 
Fungi. 
Podosphaera, Kunze. 
Perithecia globose or globose depressed; ascus solitary; spores 8. Ap- 
pendages or some of them dichotomously branched at the apex. In P. leuco- 
tricha the appendages are of two kinds. 
Key to Iowa Species of Podosphaera. 
Appendages of one kind. 
Appendages of two kinds 
1. Podosphaera oxycanthae (DC.), DeBary. 
Podosphaera kunzei Lev. Bessey, The Erysiphei. 
Podosphaera minor Howe, Bessey, The Erysiphei. 
Podosphaera tridactyla DBy. Bessey, Prel. List, Ames Flora. Hitchcock, Par- 
tial List Iowa Powdery Mildews. 
Podosphaera oxycanthae (DC.), DBy. Fink, Blights, etc., of Fayette. 
Amphigenous, mycelium variable, persistent or evanescent; perithecia scat- 
tered or gregarious in clinging masses, 64-90 micra in diameter, cells 10-18 micra 
wide; appendages 4-30 in number, %-6 times the diameter of the perithecium, 
septate, dark brown for more than one-half their length, apex 2-4 times 
dichotomously branched, branches usually short, often swollen, tips recurved; 
ascus 58-99x45-75 micra; spores 18-30x10-17 micra. 
On Crataegus coccinea L. Ames, X (X), Iowa City, July 9, 1894 (Shimek). 
On Crataegus punctata Jacq. *Ames, July, 1886 (Hitchcock) ; Iowa City, 
Aug., 1886 (Hitchcock). 
On Crategus tomentosa L. *Ames, July, 1886 (Hitchcock) ; Iowa City, Oct. 
23, 1886 (Macbride). 
On Prunus americana Marsh. Ames, 1891 (Raymond) ; Sept., 1890 (X) ; 
Decatur Co., Oct., 1904 (Anderson) . 
On Prunus avium L. Decatur Co., Aug. 31, 1905 (Anderson). 
On Prunus besseyi Bailey. Decatur Co., Oct., 1904 (Anderson). 
On Prunus cerasus L. Ames, Sept. 1, 1877 (Bessey), 1891 (Raymond), Sept., 
1892 (Carver), Aug. 20, 1894 (Sexton), Sept. 13, 1894 (Stewart & Stew- 
art), July 22, 1896 (Carver) ; Decatur Co., Aug., 1904 and 1905 (Anderson) ; 
Greenfield, Sept. 13, 1893 (Stewart); Iowa City, Oct. 1, 1886 (Macbride), 
1895 (Shimek). 
On Prunus pumila L. Ames, July 20, 1894 (Sexton), Aug. 31, 1894 (Stewart 
& Stewart), Oct. 19, 1892 (Carver). 
On Prunus sp., Ames, Sept. 9, 1892 (Pammel) ; Fayette, Sept., 1893 (Fink) ; 
*Ames, July, 1886 (Hitchcock). 
On Sanguisorba canandensis L. Forest City, July 17, 1896 (Shimek). 
This is a very common species, especially on the cultivated cherry 
(Prunus cerasus). It distorts the leaf and causes premature drop- 
1. P. oxycanthae 
2. P. leucotricha 
