3IO Journal of Agricultural Research voi. xiir, no. 6 



leaf. Lesions appear as elongate yellow blotches, which soon turn a 

 dark chocolate-brown. 



The killed area rarely girdles the entire stem. Pycnidia are not as 

 abundant as on the leaf. Apothecia have been found on stems but once, 

 and then not well developed or abundant. No case has yet been observed 

 where a plant has appeared to be seriously affected by the presence of 

 this disease on the stem. 



THE CAUSAL ORGANISM 

 TAXONOMY 



In the previous report (lo) the writer expressed the opinion that the 

 fungus causing the yellow-leafblotch of alfalfa was Phyllosticta medi- 

 caginis (Fuckel) Sacc. (originally described as Ascochyta medicaginis 

 Fuckel; 4), and that experimental evidence indicated that this species of 

 Phyllosticta is the conidial stage of Pyrenopeziza medicaginis Fuckel, 

 which appears later on the dead leaves of this host. Additional experi- 

 mental evidence has confirmed this opinion. 



Shortly after this report had been made, an earlier name applied to 

 the conidial stage of this fungus was found. A comparison of the 

 descriptions indicated that Phyllosticta medicaginis was identical with a 

 fungus which had previously been described by Desmazieres under the 

 name ' 'Sporonema phacidioides" (5). A comparison of the type speci- 

 men of 5. phacidioides * with the type specimen of Phyllosticta medi- 

 caginis ^ was kindly made by Dr. W. G. Farlow. He decided that the 

 fungi to which the two names were applied were identical, and that the 

 names should therefore be regarded as synonyms. 



In addition to the names already mentioned, "Gloeosporium mori- 

 anum Sacc." has been suggested by Von H5hnel (6) as belonging to this 

 synonymy. From an examination of the description of G. morianum 

 it appeared to the writer that Von Hohnel was probably correct. There- 

 fore specimens of Sporonema phacidioides were sent to Dr. P. A. Saccardo 

 with the request that they be compared with the type specimen of G. 

 morianum. Dr. Saccardo kindly made the comparison and assured the 

 writer that they are identical. Thus, the synonymy of the conidial 

 stage of the fungus is as follows : 



Sporonema phacidioides Desm., 1847, Ann. Sci. Nat. Bot., s. 3, t. 8, p. 



172-192. 

 Ascochyta medicaginis Fuckel, 1869/70, Jalirb. Nassau. Ver. Nattirk., Jahrg. 



23/24, P- 388. 

 Phyllosticta medicaginis (Fuckel) Sacc, 1884, Syll. Fung., v. 3, p. 42. 

 Gloeosporium morianum Sacc, 1892, Syll. Fung., v. 10, p. 458. 



1 Desmazieres, J. B. H. J. plantes cryptogames de France, fasc. 33, no. 1645. Lille, 1847. 



2 Fuckel, Leopold, fungi REffiNANi exsiccati. no. 488. 1863. 



