68 
The Ohio Naturalist. 
[Vol. X, No. 7, 
Sphaerotheca phytoptophila, Kell & Swingle. Mycelium thin; 
perithecia 60-78 / 1 in diameter, inner wall separating easily; 
cells 10 p, obscure; appendages few, irregular, often septate, 
usually longer than diameter of perithecium; ascus 42 x 60 to 
50 x 75 p\ spores 8, 12 x 20-15 x 25 p. 
Host-plant, the distorted branches produced by the Phytoptus 
growing on Celtis occidentalis. 
Specimens in the Ohio Herbarium from Preble Co., Brown Co., Mt. 
Gilead, W. A. Kellerman; Morgan Co., Kellerman and Jones. 
Otherwise reported in Ohio from Lima, W. A. Kellerman, Columbus, 
A. D. Selby. 
Erysiphe Hedw. 
Key to the Ohio Species. 
1 . Perithecia not usually maturing on living host plant .... graminis 
Perithecia usually maturing on living host plant 2 
2. Asci 8-spored polygoni 
Asci 2-spored 3 
3. Asci usually 10-15, haustoria lobed galeopsidis 
Asci same, haustoria not lobed cichoracearum 
Erysiphe graminis DC. Mycelium rather persistent; perithe- 
cia large, 135-280 p in diameter; cells obscure; appendages short, 
simple, light brown; asci 9-30, 70 x 25-108 x 40 p, long-stalked; 
spores 8, 20 x 10-23 x 13 p. 
Host plants in Ohio Herbarium: Poa pratensis, College Hill, W. H- 
Aiken. 
Otherwise reported in Ohio; Triticum valgare, Columbus, F. Detmers, 
Lima, W. A. Kellerman; Poa pratensis, Columbus, W. A. Kellerman; 
Agropyrum, Ashtabula Co., Sara F. Goodrich. 
Erysiphe polygoni DC. Mycelium usually thin; perithecia 
65-180 p in diameter; cells 10-15 p ; appendages variable, usually 
many, 5-15 times diameter of perithecium, simple, sometimes 
flexuose; asci 2-10, 46 x 30-72 x 45 p, sometimes with short 
stalk; spores 3-8, 19 x 9-25 x 14 p. 
Host plants in Ohio Herbarium: Caltha palustris, Columbus, W. A. 
Kellerman ; Polygonum aviculare, Sandusky Co., Ottawa Co., W. A. Keller- 
man, Toledo, F. D. Kelsey; Polygonum sp., Miami Co., W. A. Kellerman 
and W. R. Beatty, Adams Co., Athens Co., W. A. Kellerman; Polygonum 
erectum, Franklin Co., F. L. Stevens, Belmont Co., Sugar Grove, Brown 
Co., W. A. Kellerman; Scutellaria laterifolia, Cuyahoga Co., E. Claassen; 
Oenothera biennis, Lake Co., E. Claassen; Thalictrum purpurascens, 
Lake Co., E. Claassen, Lupulinus perennis, Erie Co., F. L. Stevens, Toledo, 
F. D. Kelsey; Eupatorium sp., Columbus, C. M. Weed; Celmatis virginiana, 
Columbus, C. M. Weed; Aquilegia canadensis, Champaign Co., W. C. Wer- 
ner. 
Otherwise reported in Ohio: Aquilegia canadensis, Columbus, F. 
Detmers; Clematis virginiana, Columbus, A. D. Selby, F. Detmers; 
Clematis sp. (cult), Columbus, A. D. Selby, F. Detmers, Waynesville, 
W. A. Kellerman; Desmodium canescens, Columbus, A. D. Selby; Lirio- 
dendron tulipifera, Columbus, Fairfield Co., A. D. Selby. 
