SoS ee ee a 
GRIFFITHS: West AMERICAN FUNGI 293 
again in 1896 Stipa viridula was almost completely prevented 
from making seed in a certain locality while Agropyron occidentale 
in actual contact with it was entirely unaffected. In 1896 and 
1897 at Aberdeen, S. D., the same grasses were observed grow- 
ing together, but in this instance the Agropyron was smutted while 
the Stipa was entirely free. In the vicinity of Billings, Mont., in 
1900 smutted plants of Elymus striatus and Agropyron occidentale 
Were both growing with Stipa viridula in different situations, but 
the latter was entirely unaffected. During the past summer Z/y- 
mus condensatus was very badly smutted at Quinn River Crossing, 
Nev. Distichtis spicata growing about its base was entirely unaf- 
fected. In another locality in the same general region where the 
hosts bore the same relation to each other Distichlis was badly 
smutted while Elymus was perfectly free from the disease. In one 
locality, near Andrews, Oregon, they were both found smutted 
Stowing side by side. 
There are slight differences in spore characters in some of these 
forms, but they are too slight to warrant the establishment of spe- 
“es upon them. The spores of the forms on Stipa occidentale are 
4 trifle larger than any of the others while the form on Distichlis 
has Spores with somewhat thicker walls and more restricted cen- 
tral area. The form on Agyropyron occidentale from Billings, 
Mont., has the epispore much darker than any of the others. 
hese differences are trifling of course, but when emphasized by 
the above field observations their importance is magnified very 
ee It might be added that these differences are fully as great 
S$ those which led to the establishment of U. funalis E, & E. on 
tocoma cuspidata, 
Ustiraco miNoR Norton 
This Species is very abundant and destructive all through 
Southern Arizona. There appears to be in my material a slight 
ference in the size of the spores of all collections of Bouteloua 
oigostachya whether from Montana or Arizona. All collections 
-. this host are, therefore, referred to U. filifera Nott. (217 and 
78), UV. minor, as represented in my collections from Arizona, 
PPeuts on Bouteloun polystachya (220), B. aristidoides (218), B. 
. rlopoda (219), B. bromoides (227), and Pappophorum Wrightit 
& 724), It is very destructive to all of these species and may be 
