190 
interweaving much with other threads. Conidia-bearing branches are 
scarce, and the only perfect (?) one I could tine bore three conidia. 
Erysiphe communis, (Wallr.) Fr. Hosts: (Enotliera albicaulis , 
Sand Coulee; Oxytropis Lamberti , Sand Coulee, Great Falls, Valley of 
the Teton, Craig, Helena, Deer Lodge, Dillon, Spring Hill; Astragalus 
Canadensis. Helena (Kelsey), Belt Mountains ; A. multiflorus , Belt Mount¬ 
ains; A. decumbens, Belt Mountains; A. hypoglottis , Sand Coulee, Hel¬ 
ena, Willis; Pisum (cultivated), Willis, Spring Hill; Vicia Americana , 
var. linearis , Sand Coulee; Trifolium longipes , Deer Lodge Valley and 
Belt Mountains; Lupinus parviflorus. Dee r Lodge and Spring Hill; 
Amelanchier alnifolia , Helena (Kelsey), Sand Coulee; A. maculatum , 
Sand Coulee; Ranunculus repens , Helena, Deer Lodge, Willis; R. ma- 
cranthus , Great Falls, Belt Biver ; R. Cymbalaria , Sand Coulee, Helena, 
Deer Lodge, Dillon, Willis, Glendale, Melrose, Spring Hill, Valley of 
the Teton ; R. sceleratus , Sand Coulee, Helena. Doubtless on many 
other hosts. The forms on Ranunculacece commonly have very dark ap¬ 
pendages, especially the form on R. Cymbalaria. The appendages of 
the forms on Leguminosce are lighter or even entirely colorless, and often 
indistinguishable from the mycelium at maturity. This fungus is espec¬ 
ially destructive to Ranunculus Cymbalaria , Oxytropis Lamberti , and 
cultivated Pisum. 
Erysiphe galeopsidis, DC. Host: 8tacliyspalustris, Helena (Kel¬ 
sey), collected August 26, of this year, but not well matured. The abun¬ 
dant mycelium develops on all parts of the plant above ground. Occa¬ 
sionally asci are seen nearly double the ordinary length, constricted at 
the middle and septate; they were seen (several in one perithecium and 
one or two in others) clustered with the other asci. The spores, which 
are not mature, are usually narrowly elliptical to linear and acute at 
both ends. 
Erysiphe uichoracearum, DC. Hosts: Mertensia Sibirica , Belt 
Mountains ; Phaeelia Menziesii , Silver City (Kelsey); Parietaria debilis , 
Sand Coulee; Verbena hastata , Helena (Kelsey); Galium Aparine , Sand 
Coulee; Eeliinospermum RedoivsJcii , Helena (Kelsey); Solidago Missouri- 
ensis , Sand Coulee, Belt Mountains; 8. serotina , Sand Coulee, Belt 
Mountains, Helena, Deer Lodge, Dillon, Spring Hill; 8. rigida , Sand 
Coulee, Belt Mountains, Belt Biver, Craig, Helena, Deer Lodge, Butte, 
Silver Bow Junction, Dillon, Willis, Spring Hill, Valley of the Teton ; , 
8. nana , Bell Mountains ; 8. occidentalism banks of the Upper Missouri 
Biver; Aster Icevis and forms, Sand Coulee, Belt Mountains, Helena, 
Deer Lodge, and Dillon ; A. conspicuus , Belt Mountains ; A. longifolius , 
Belt Mountains, Helena, Warm Springs Asylum; A. commutatus, Sand 
Coulee, BeltBiver, Cora Creek Station, Great Falls, Helena, Deer 
Lodge, Dillon, Willis; A. canescens and forms, Sand Coulee, Belt Mount¬ 
ains, Belt Biver, Mt. Helena, Deer Lodge, Warm Springs Asylum, 
Spring Hill; A. multi for us. Belt Biver, Otter Creek, Cora Creek Sta¬ 
tion ; A. foliaceus and vars., Sand Coulee, Helena, Deer Lodge, Dillon, 
Warm Springs Asylum ; A. adscendens, BeltBiver; Erigeron macranthus, 
