6 
COLORADO EXPERIMENT STATION 
organized, presenting the appearance of a gelatinous mass, which is 
especially abundant in the lumbar region and about the exits of the 
spinal nerves. In most locoed females the ovaries are found in a dis¬ 
eased condition. 
Cause: According to the report of Albert C. Crawford, pharm¬ 
acologist, poisonous plant investigation, “It is the inorganic constitu¬ 
ents, especially barium, which are responsible for this poisonous action, 
at least in the plants collected at Hugo, Colo.” 
Ridding the Ranges of Loco Weeds: “In regard to the possibility 
of killing the weeds, it was found that this could readily be done in the 
case of fenced pastures. This is especially feasible with Astragalus 
mollissimus, because it occurs in comparatively small patches. Aragal- 
lus lamberti has a wider distribution, but it is not at all impossible to 
destroy this weed when in pastures. There seems to be no way of 
ridding the ranges of these weeds, however.” 
Treatment: “In regard to the second phase of remedial work, it 
was found that locoed cattle can in most cases be cured by a nurse of 
treatment with strychnine, while locoed horses can generally be cured 
by a course of treatment with Fowler’s solution. The animals u idcr 
treatment must not be allowed to eat the loco weed and ;h') be 
given not only nutritious food, but, so far as possible, food wdh laxa¬ 
tive properties. To this end magnesium sulphate was administered to 
correct the constipation which is almost universal among locoed ani¬ 
mals. It should be noted, too, that magnesium sulphate may serve to 
some extent as an antidote to the poison. 
It may be added, in regard to the question of immunity, that loco 
poisoning comes on in a slow and cumulative manner, so that there is 
no possibility of animals becoming immune.” 
LARKSPUR. 
Barring the several species of loco weed, by far the most impor¬ 
tant poison weed in the State is three or four species of larkspur. The 
loss to the State from this source is something like $50,000 per annum. 
In almost every instance where we have been called upon to investi¬ 
gate the poisoning of live stock in the mountainous sections of the State 
it has proved to be some species of this deadly family. The entire plant 
is poisonous up to the time that it flowers. It then not only becomes 
unpalatable to most animals, but loses a large part of its poison. When 
in flower it can easily be distinguished from all other plants by the 
color and shape of the flower, which has a projection on the back side, 
hence the name larkspur. All the different species have this character¬ 
istic shape, the blue or white flower, and so far as we know now all the 
different species are poisonous. 
The poisoning occurs mostly in the spring when the plant is young, 
and during or immediately after a snow or rain storm. Cattle and 
sheep are much more frequently affected than horses. The animal 
usually starts for water, may fall down several times, stagger to its 
feet and try to keep going. Letters have been received frequently from 
different sections of the State describing a heavy loss through poisoning 
and accusing an unscrupulous neighbor of having willfully placed 
