100 James G. Horsfall 



( lercospora seems a more logical place for the fungus than the genus 

 Passalora, because the latter has many-septate conidiophores, while 

 these are chiefly continuous or rarely septate. In the absence of type 

 material of S. graminis, of course, no disposition can be considered as 

 final; nevertheless the fungus can be included without reasonable doubt 

 as Cercospora graminis (Fckl.) comb, now The following names are 

 listed as synonyms with the authority for considering them as such inclosed 

 in parenthesis after each: 



Scolecotrichum graminis Fckl. (writer, 1929) 



Passalora dactylina Pass (Lindau, 1907:794) 



Passalora graminis (Fckl.) Hoh. (writer, 1929) 



Scolecotrichum graminis var. nana Sacc. (Von Hohnel, 1924:6) 



Scolecotrichum compressum Allesch. (Von Hohnel, 1921:7) 



Cercospora graminicola Tracy & Earle (writer, 1929) 



Species that are closely related to if not identical with Cercospora 

 graminis are Scolecotrichum graminis var. avenae (Eriksson, 1891:28); 

 S. stictidum 5 (Berk, and Br.) (Oudemans, 1874:315); S. graminis (Fckl.) 

 var. brachypoda 6 (Spegazzini, 1911:436); Passalora punctiformis and P. 

 horde i (Otth, 1868). 



The identity of these species cannot well be determined in the absence 

 of the type material. The similarity of their descriptions evidently 

 indicates that further investigation might result in their incorporation as 

 synonyms of Cercospora graminis. Azozma punctum Lacr. has sometimes 

 been included as a synonym, but von Hohnel (1924:6) states that this 

 is an error. 



Fuckel (1869:107) listed Scolecotrichum graminis as the conidial stage 

 of Sphaeria recutita Fries (1822:524), although as Schroeter said (1908: 

 498), " aber wohl ohne geniigenden Grand." Von Hohnel (1924:6) 

 referred this fungus to Carlia recutita (Fr.) Hoh. 



Single spore cultures of C. graminis produce what are undoubtedly 

 perithecial primordia on sterilized wheat grains, but no method of treat- 

 ment has yet induced these to form asci and spores.. Exposing the cultures 

 to ultra-violet light and to outside conditions that were successful for 

 Pseudoplea trifolii was of no avail in this case. In the spring of 1928 

 perithecia of a fungus provisionally identified at the time as Mycosphaerella 

 sp. were found on overwintered leaves of orchard grass bearing conidial 

 fructifications of C. graminis. The ascospores were biseriate, hyaline, 

 and one-septate with one cell frequently somewhat larger than the other. 

 Ten spores measured 7.2 to 9.0 fx by 23.0 to 32.4 n in size, thus corresponding 

 with conidia of C. graminis. An attempt was made to get a pure culture 



5 Oudemans' figure is typical of C. graminis and the spores measure 40/' long according to Lindau (1907: 

 794). 



6 The description of this fungus might well pass for that of C. graminis. 



