Colorado Plants Injurious to Pivlstock 
9 
fungi including mildew. The extent to which the mildews are pois¬ 
onous has never been determined but they are generally accused of 
causing inflammation of the digestive tract and other serious digest¬ 
ive disorders. 
Smut 
This is a large group of well-known fungi. The best known 
are those occurring on the cereals. Among these may be mentioned 
corn smut, stinking smut or bunt and loose smut of wheat, loose 
and covered smuts of barley, loose and kernel smuts of oats, kernel 
and head smuts of sorghums. Besides these well-known smuts on 
cereals a number occur on native plants, including grasses and other 
forage plants. Among these may be mentioned the smut on brome 
grasse*s, barnyard grass, Indian millet, manna-grass, squirrel-tail 
grass, wild rye-grass, fescue-grass, hair-grass, slender wheat-grass, 
etc. Buffalo-grass and grama-grass, the two most abundant and im¬ 
portant forage grasses of the Great Plains, are each infested with 
a smut. These smuts may become very abundant in seasons favor¬ 
able to their growth. They are especially noticeable in spring and 
early summer. Hence it is seen that smuts, as a group, are widely 
spread throughout the state, occurring on both cultivated and wild 
plants. 
Smuts are conspicuous on account of the black, dusty spore 
masses, which, as a rule, break out on the flowering heads, but also 
frequently on leaves and stems. A single smutted corn or sorghum 
plant may produce tremendous quantities of dry, black spores. 
Poisoning by smuts .—It has been a common belief for many 
years that smuts are injurious to livestock. Feeding experiments, 
however, have demonstrated that no bad results follow from cattle 
eating any of the smuts. Of course, they may cause a sore throat 
or irritation of the throat when administered in large quantities, 
but the injury is not fatal. Furthermore, there seems to be no ill 
effects resulting from feeding siloed smutty grain or forage. 
Rusts 
The rusts are an exceedingly large and widely distributed class 
of fungi. The best known are those on cereals. There are rusts on 
wheat, oats, barley, rye, and corn. 
Any number of cultivated and native plants, many of which are 
grazed, is the home of rusts. Common forage grasses that are fre¬ 
quently rusted are timothy, orchard-grasses, fescue-grasses, brome- 
grasses, wheat-grasses, rye-grasses, marsh-grass, squirrel-tail, salt- 
grass, grama-grass, wire-grass, and many others; in fact there are but 
few grasses that are not infested more or less with some rust. There 
are also rusts on peas, vetches, beans, clover, alfalfa, and a great many 
of the herbaceous plants that may be eaten by stock. Hence it is readily 
seen that rusts are common everywhere and on a great variety of 
