i6 
CoivORADO ExPE:RIMJ:NT STATION 
Colorado from low to high altitudes. It is also found in low ground, 
particularly in a clay soil. 
Poisoning by Bquisetnm .—^Equisetum is so abundant that most 
people do not suspect that it is poisonous. It is found in much of 
the native hay of Colorado. Many reports have come to the Experi¬ 
ment Station of serious poisoning of animals that could only be 
attributed to horsetail. We have never had reports of animals other 
than horses being affected. 
Symptoms .—The first evidence of the trouble is more or less 
unthriftiness and in most cases diarrhoea. The horse appears thin 
and the muscles wasted. After two to five weeks, according to the 
amount of horsetail in the hay, the horse begins to lose control of its 
limbs, sways and staggers, although its eyes look bright and the appe¬ 
tite is normal. After the muscular symptoms become pronounced the 
horse will refuse to lie down and if it gets down will struggle vio¬ 
lently to get to its feet- The extremities are cold, and horses that are 
affected from eating Equisetum suffer greatly from the cold in the 
winter time. Young horses develop the symptoms much quicker 
than older ones. Some claim that horses develop a depraved appetite 
for the weed. 
T^'eatniev.t. —Stop feeding- the Equisetum hay and give a quart 
of raw linseed oil as a physic. After the physic has operated give a 
teaspoonful of powdered nux vomica, mixed with the feeds of grain, 
three times a day. If the horse becomes very weak, he should be 
supported by slings. These cases, if given prompt attention and an 
appropriate treatment, will recover in most instances. 
EVERGREENS (Conifers) 
The pines, spruces, firs, junipers and cedars are widely distrib¬ 
uted over Colorado. They have not been known to poison stock. 
CAT-TAiL (pTypha latifolia) 
This common plant, found in marshes at lower altitudes in Colo¬ 
rado, is suspected of being poisonous. 
GRASSES 
A number of grasses are known to poison stock, while others 
injure them mechanically by means of their sharp beards or bristles. 
Grasses are closely related to and frequently mistaken for sedges. 
Sedges, however, have solid stems, usually 3-cornered. They prefer, 
as a rule, moister situations than grasses. 
POISONOUS GRASSES 
Johnson Grass (Andropogon halapcnsis) 
This is a perennial from rootstocks. The plant is from 3 to 5 
feet tall. The leaves are broad, flat and smooth. The inflorescence 
or flowering head often measures i foot or more in length, and 
branches profusely. The spikelets are in pairs; one of these has a 
short stalk, the other is without. The spikelets are covered with long, 
soft hairs, and are often purplish in color when mature. A beard 
may be present or absent. 
