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Ustilago Montaniensis Ellis & Hoi way, on Mulilenbergia glomerata var. 
setiformis , first discovered by the writer December 12, 1887. This ap¬ 
pears to be one of the most destructive species of Ustilago we have. The 
host plant begins to “head out” when it is 3 inches high. These early 
panicles are lateral, and smaller than the final terminal panicle, which, 
under favorable conditions, is developed by the time the plant is 24 or 
30 inches high. Culms affected by the fungus are generally stunted 
and thickened, becoming harsh and knotty. Their panicles are usually 
aborted from first to last. Sometimes only the lower or middle spikelets 
in the dense spikes are infected, the rest being perfect and producing 
seed. In the case of the small lateral panicles, which are mostly 
smutted entirely, the panicles do not grow out of the sheaths, but 
are inclosed by the united and membranous bases of the sheathing 
leaves. As the fungus develops this usually cylindrical or oblong sac 
enlarges and gradually loses its leaf character, except where its two 
parts extend above and beyond the inclosed panicle. The membrane 
surrounding the smut has by this time become a leaden-gray color, and 
exceedingly thin and chartaceous. Where only more or less isolated 
small spikes and spikelets of a panicle are affected, the surrounding 
membrane is formed by the uniting of the glumes, which are free and 
maintain their true character only at their tips. 
Three times out of five if the fungus is present it affects all the pan¬ 
icles. When the very first one appears iu an infected plant it will be 
found full of smut, and each succeeding panicle as it is developed will 
be found to be in a similar condition, so that it is evident the fungus 
develops with the host. The host is a perennial, and so far as I have 
been able to discover by examining old and new culms, representing 
four years’ growth, the plant once attacked is affected each succeeding 
year until its death. As Mulilenbergia is a valuable grass and will soon 
be common in cultivation, this fungus ought to receive careful attention. 
Erysiphe graminis is a common pest in some sections, notably in 
southern Montana, west of the main divide of the Rocky Mountains. 
It affects chiefly the Poas and is especially damaging to Poa tenuifolia , 
one of our most valued forage grasses. The asci of the fungus contain 
ripe spores in November. 
Puccinia rubigo-vera is common everywhere. I have collected it 
on fourteen species of native grasses. It is most damaging to Elymus 
condensatus. Wheat and oats do not suffer from it as yet. 
Puccinia tanaceti occurs on many hosts. The cultivated Sun¬ 
flower is sometimes ruined by this fungus. The common Sage-brush 
(Artemisia tridentata) is frequently attacked so overwhelmingly by 
Puccinia tanaceti that its flowers dry up and its leaves fall off. The 
fungus attacks the younger stems and shoots, blackening them also. I 
have found it on five species of Artemisia , viz: A. tridentata , A. cana , 
A. Ludoviciana , A. frigida, and A. dracunculoides. On A. dracunculoides 
and A. Ludoviciana I have found one of the numerous JEcidium com - 
