LEAF-SPOT OF ALFALFA AND RED CLOVER. 9 
absent. In striking contrast is the scarcity of these spores on my- 
celium from spores of P. trifolii. (Fig. 4.) Never are they pro- 
duced in great numbers, and frequently they are entirely absent from 
all but a few fungous colonies. Thus, the striking abundance of these 
structures on mycelium of P. medicaginis and their scarcity on 
Fie. 3.—Mycelium and conidiumlike structures developing from ascospores of Pseudo- 
pexiza medicaginig on agar agar. X 400. 
mycelium of P. trifold furnish an easy morphological distinction 
between the two species. 
REPORTED CONIDIAL STAGES OF THESE FUNGI. 
It is a matter of some interest to note that all the studies of 
Pseudopeziza on alfalfa and clover 
which have been made by European 
mycologists and pathologists with 
but a single exception (Briosi, 
1888) have contained a discussion 
of an associated conidial stage. 
Thus at least three, perhaps four, 
imperfect fungi have been assigned 
to this role in addition to the coni- 
diumlike structures which are pro- 
duced in culture. A summary of 
the evidence on the basis of which 
the association of these conidial Fic. 4.—Mycelium developing from an 
stages has been made is here given. rests comand ee ane pone 
The first of these fungi to be 
regarded as a conidial stage of Pseudopeziza medicaginis was Sporo- 
nema phacidioides Desm. Since the writer has a previous article 
(Jones, 1918) traced the development of the purely observational 
evidence on which this association was based and has shown that this 
Sporonema is the conidial stage of Pyrenopeziza medicaginis Fckl., 
no further discussion is necessary here. 
89950°—19——2 
