1 68 The Ohio Naturalist. [Vol. X, No. 7, 



Sphaerotheca phytoptophila, Kell & Swingle. Mycelium thin ; 

 perithecia (30-78 a in diameter, inner wall separating easily ; 

 cells 10 It, obscure; appendages few, irregular, often septate, 

 usually longer than diameter of perithecium; ascus 42 x 60 to 

 50 X 75 ,u; spores 8, 12 x 20-15 x 25 /<. 



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, Columl)us, 

 A. D. Selby. 



Erysiphe Hedw. 



Key to the Ohio Species. 



1. Perithecia not usually maturing on living host lAunt . . . . 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 galcopsidis 



Asci same, haustoria not lobed cichoraccarnm 



Erysiphe graminis DC. Mycelium rather persistent; perithe- 

 cia large, 135-280 a in diameter; cells obscure; appendages short, 

 simple, light brown; asci 9-30, 70 x 25-108 x 40 /{, long-stalked; 

 spores 8, 20 x 10-23 x 13 /«. 



Host plants in Ohio Herbarium: Poa pratensis. College Hill, W. H- 

 Aiken . 



Otherwise reported in Ohio; Triticum valgare, Columbus, F. Detmers, 

 Linia, W. A. Kellerman; Poa pratensis, Columbus, W. A. Kellerman; 

 Agropyrum, Ashtabula Co., Sara F. Goodrich. 



Erysiphe polygoni DC. Mycelium usually thin; perithecia 

 65-180 /( in diameter; cells 10-15 //; 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 ix. 



Host plants in Ohio Herbarium: Caltha palustris, Cokmibus, 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. Kellemian; 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: Acpxilegia 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. 



