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CULTURAL CHARACTERS OF THE CHESTNUT-BLIGHT FUNGUS 



AND ITS NEAR RELATIVES/ 



By C. L. Shear, Pathologist in Charge of Small- Fruit Diseases, and Neil E. Stevens, 



Forest Pathologist. 



INTRODUCTION. 



The cliestnut-bliglit fungus EndotMa 'parasitica (Murr.) And. and 

 And. has been found to have two or three rather closely related spe- 

 cies in this country, as follows: EndotMa radicalis (Schw.) DeNot., 

 E. radicalis mississijypiensis, and E. gyrosa (Schw.) Fr. One or two 

 other species have been found, but are not likely to be confused with 

 E. parasitica. 



EndotMa radicalis (Schw.) DeNot. has already been well described 

 by the Andersons ^ as E. virginiana, and also by Clinton ^ as E. gyrosa. 



A study of the type specimen of SpTiaeria radicalis Schw., made by 

 the senior writer,* has shown that this name properly belongs to the 

 plant having narrowly oval ascospores, usually ranging from 6 to 9 

 by 2.5 to 3.5 microns. In general macroscopic appearance this spe- 

 cies very closely resembles EndotMa parasitica, and we were at first 

 inclined to the belief that the two were not specifically distinct, but 

 after a careful study of hundreds of specimens, cultures, and inocu- 

 lations of both species from many localities no series of intergrading 

 forms, either morphological or physiological, has been found. At first 

 glance the form described below might be so considered, but it is 

 quite distinct and constant in its cultural characters. Unless such 

 intergrading forms should be discovered later there seems to be no 

 way of escaping the conclusion that the two organisms are specifically 

 distinct, according to the most conservative taxonomic standard of 

 species prevailing at present in mycology. The lack of fluctuating 

 variations in these organisms, both in nature and in artificial cultures, 

 is in striking contrast with the species of Glomerella, which, according 

 to the senior writer's experience, showed few or no stable characters 

 of any kind. 



'Issued July5, 1913. 



Anderson, P. J., and Anderson, H.W. The chestnut-blight fungus and a related saprophyte. Phy- 

 topathology, V. 2, no. 5, pp. 204-210, 1912. 



; Clinton, G. P. The relationships of the chestnut-blight fungus. Science, n. s., v. 36, no. 939, pp. 

 907-914, 1912. 



*C. L. Shear. The type of Sphaeria raiicalis Schw. To appear in Phytopathology, v. 3, no. 3, 1913. 



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