May6, i9i8 Yellow-LeafMotch of Alfalfa 311 



The first description of the ascigerous stage of Sporonema phacidioides 

 was given by Fuckel in 1870 (4) under the name " Pyrenopeziza medicagi- 

 nis." No record of any other collection of this fungus than Fuckel's 

 type collection^ has been found. Since Pyrenopeziza medicaginis 

 Fuckel is the name of the ascigerous stage, it is the name which should be 

 applied to the fungus as a v/hole, according to present rules of nomen- 

 clature. 



The fact that Sporonema phacidiouies is found to be the conidial stage 

 of Pyrenopeziza medicaginis is a matter of considerable interest, because 

 this fungus has long been regarded as a possible conidial stage of the 

 leafspot fungus Pseudopeziza medicaginis. This misconception appears 

 to have developed in the following manner. When, in 1847, Desmazieres 

 described S. phacidioides, making it the type species of the new genus 

 (5), he noted that the pycnidia opened by irregular valves in much the 

 same manner as the apothecia of Pseudopeziza medicaginis (then known 

 as Phacidium medicaginis), and that it occurred in association with this 

 species of Phacidium. This common morphological feature and the 

 association of the fungi suggested the species name ''phacidioides." 

 Next, in 1865, during the course of a discussion of Pseudopeziza medi- 

 caginis, Tulasne {14) made a note of the fact that the two fungi occur 

 together. Although from a careful study of Tulasne's statement it does 

 not appear that he intended to indicate more than an incidental associa- 

 tion of the two fungi, yet subsequent writers generally have interpreted 

 it as pointing out a probable relationship. For instance, Brefeld (7) 

 says: 



Von ihr [Pseudopeziza medicaginis] giebt Tulasne Pycnidien mit kleinem langlich 

 eiformigen Sporen an, die in ahnlicher Weise wie die Ascusfruchte ihre Hymenium 

 basslegen sollen. 



Thus, scattered through the literature of Pseudopeziza medicaginis 

 from the time of Tulasne's statement, are found, chiefly in European 

 literature, a large number of references to the conidial stage of this 

 fungus which clearly indicate that Sporonema phacidioides was referred 

 to, although it was not always specified by name. The persistence of 

 the idea that 5. phacidioides is the conidial stage of Psexidopeziza medi- 

 caginis is all the more surprising, in view of the fact that there appear 

 to have been no recent collections of the former on alfalfa, and all the 

 older collections were from France and Belgium only. 



The reason for the scarcity of collections of Sporonema phacidioides 

 is obviously as follows: In 1870 Fuckel (4) had described what now 

 appears to be the same fungus under the name " Ascochyta medicaginis." 

 In 1884 Saccardo {13) transferred the species to the genus Phyllosticta. 

 Thus, almost all the collections of this fungus outside of France and 

 Belgium were placed under one or the other of these two names. And 



1 Fuckel, Leopold, fungi rhenani exsiccati. no. 1594. 1865. 



