Colorado Pi,ants Injurious to Livestock 
17 
Johnson g:rass has been reported from several localities in Colo¬ 
rado. In some places it is cultivated, and from such it may escape and 
become a weed. 
Johnson grass is undoubtedly poisonous under certain conditions. 
Discussion of this subject will be found under the head of Sorghums. 
vSoRGiiUMS {Andropogon sorghu-in) 
'Idle sorghums comprise a large and well-known group of plants 
that are used both for their grain, and as hay and fodder. Under the 
name “sorghum” are included sweet sorghum or sorgo, milo, durra, 
kafir, broom corn, kaoliang, shallu, feterita, and Sudan grass. All are 
annual plants, ranging in height 'from 3 to 15 feet. The “heads” 
vary considerably in size, shape and color. 
Poisoning by sorghums. —A large number of plants are known 
to be poisonous from the presence of prussic or hydrocyanic acid. 
This acid is known to be one of the most deadly poisons, and it results 
from the presence in the plant of what is known as a glucoside which 
must be acted upon by a ferment. The most important and best 
known of all the glucosides is amygdalin. A large number and a 
great variety of plants contain a hydrocyanic acid producing gluco¬ 
side. Plants that are conspicuous in this class are sorghum, kafir corn, 
Johnson grass and wild cherry. 
Conditions under which poisoning may occur. —The second growth 
of sorghum is generally accused of being the more dangerous, but in 
the late summer wdien the second growth appears the entire plant 
contains poison. Kafir corn is the least dangerous when grown luxu¬ 
riantly under irrigation or bountiful rainfall. The conditions which 
prevail in the arid districts of Colorado are ideal for growing kafir 
corn that is most dangerous. When kafir corn has made a stunted 
growth, and in the fall for two or three weeks before frost, the most 
poisoning occurs. After it has been cured from cutting or frost, it 
has never been known to kill animals, unless it be later demonstrated 
that hydrocyanic acid is a causative factor in “Corn Stalk Disease.” 
The leaves of several species of wild cherry are very deadly to 
cattle. The special condition under which wild cherry poisons ani¬ 
mals, is when the leaves are partially wilted. 
The poison in question has been found in a great number of both 
native and domesticated plants and it is quite possible that in many 
cases where a large number of animals have died mysteriously, with¬ 
out the presence of either infection or any known poisonous plant, 
that some plant capable of developing prussic acid is responsible. 
Symptoms. —A few mouthfuls of highly poisonous kafir corn 
taken on an empty stomach have been known to kill a cow in ten min¬ 
utes. At Brighton, Colorado, thirty-two cows, after being kept in the 
corral over night, were turned into a field of kafir corn, of not over 
two acres, that had been grown above the ditch, and twenty-one of 
them were dead in half an hour and four of the others were badly 
affected.* The first thing noticed in a poisoned animal is giddiness 
and difficult breathing with spasmodic defecation and micturation. 
* Bulletin No. 77, Nebraska Experiment Station. 
