26 
BULLETIN 759, U. S. DEPARTMENT OF AGRICULTURE. 
garded, are made up either of several closely similar species or of a 
group of specialized races. 
Especially in the case of the Pseudopeziza on Medicago lupulina 
the fragmentary evidence indicates a species distinct from that on 
alfalfa. In addition to the evidence already given, the measurements 
of 113 ascospores collected under standard conditions is adduced. 
(Table VII.) 
Table VII. — Lengths of 113 ascospores of Pseudopeziza medieaginis on Medi- 
co go lupulina, measured to the nearest micron. 
Ascospores of — 
Length (microns). 
9 
10 
u 
12 
13 
Pseudopeziza medieaginis number. . 
1 
14 
59 
31 
8 
When Table VII is compared with Table II, it will be noted that 
these spores are even larger than those of Pseudopeziza trifolii. Un- 
fortunately, the cultures which were made of this fungus were de- 
stroyed, and complete evidence of the relationship of these fungi was 
not obtained. 1 Of the other hosts of P. medieaginis, less can be said. 
Field observation indicates that the fungus in Medicago falcata and 
M. hispida denticulata occurs by infection from Pseudopeziza in al- 
falfa. A collection of the fungus has been found in only one in- 
stance each on Melilotus alba and Tlcia villosa. An examination of 
a portion of the collection on Melilotus alba reveals a lesion that is in 
all respects similar to that which the fungus causes on other hosts, 
but no asci and spores by which the fungus could be identified were 
found. Certainly the occurrence of the fungus on these hosts is not 
common or of economic importance. Xo material of Pseudopeziza 
on Onobrycliis sativa or any species of Trigonella has been available 
for study. 
Of the host list of Pseudopeziza trifolii only a few species have 
been available for study. The fungus from Trifolium pratense has 
not infected any other species to produce fruiting of the fungus on 
that host. Furthermore, it has not been found fruiting on any other 
host in America except in the one instance already mentioned. Yet 
reports well supported by herbarium specimens indicate that Tri- 
folium repens and T. hybridum are abundantly infected in Italy. 
Whether this infection is by the same species of the fungus or not 
can not be determined at present. 
1 It is of interest to note that Pseudopeziza medieaginis was first described on what is 
now known as the variety icildenowii of Medicago lupulina. If it should be shown that 
Pseudopeziza on Medicago lupulina icihlenoicii is a distinct species from that on Medicago 
sativa the name Pseudopeziza medieaginis will be restricted to the fungus on the original 
host, and a new species name will be required for the fungus on alfalfa. 
