16 
BULLETIN 1245, U. S. DEPARTMENT OF AGRICULTURE. 
So far as known, the green plant does no harm. The seeds are 
poisonous and a sheep may be poisoned by a little more than an 
ounce or killed by something less than 2 ounces. The pods have 
little if any poison. Cases of poisoning occur in the winter on areas 
where feed is scanty. 
All the known cases of poisoning have been of sheep and goats. 
Animals eating the seed show depression, generally accompanied with 
diarrhea. In fatal cases the symptoms are not especially pro- 
nounced ; but the animals become weak, have labored breathing, and 
die with very little struggling. Considerable time elapses between 
the feeding and the appearance of symptoms, sometimes as much as 
24: hours. The symptoms, too, may continue several days, so that 
poisoned animals require special care until after complete recovery. 
Figure 13 shows a sheep poisoned by the coffee bean. 
LOCO PLANTS (SPECIES OF 
OXYTROPIS AND ASTRAG- 
ALUS). 
Without any doubt 
the most destructive of 
all the poisonous plants 
are those going under 
the general name of 
loco. That extensive 
losses of domestic ani- 
mals have been caused 
by loco plants has been 
claimed for a longtime, 
but it is only within 
the last few years that 
exact evidence, by care- 
ful experiments, h a s 
shown definitely that 
these plants produce the effect which has been popularly ascribed in 
them. A great deal of interest attaches to these plants because of 
Fig. 13. 
-A sheep poisoned by coffee bean (Daubcntunia 
longifolia). 
been poisoned by them, including cattle, horses, goats, and sheep, and 
also because of the difficulty of actually proving the existence of a 
poisonous principle in the plants themselves. 
The loco plants have had a place in romantic literature, as it has 
frequently been claimed that they produce the same effect upon 
human beings as upon the lower animals, and it has been a popular 
subject for the short-story writer. Xone of these stories of " locoed " 
men, however, have any substantial foundation. 
The word loco is from the Spanish, meaning crazy, and was given 
because of the supposed effect upon its victims. Loco plants have 
been heard of in practically all the open-range country of the West, 
except in the higher mountains, and there is no doubt that under 
i lie term loco disease a large number of ailments have been included. 
Experimental proof, however, has shown that there is a disease occa- 
sioned by the loco plants, with distinct symptoms and with a definite 
outcome. 
