Larkspur and Other Poisonous Peants. 
5 
obstacle to their investigation, but incidentally furnishes an in¬ 
disputable argument in favor of the necessity of educating the 
stockmen as to their identity in order that they may the more 
effectually avoid them. 
In the realm of toxicology we are still groping in the dark, 
and our best scientists have laid down before many of the stupend¬ 
ous obstacles confronting them and acknowledge defeat. Here 
are some of the difficulties with which we have to contend: 
i. Some Plants Are Poisonous Only at Certain Stages of 
Growth, The lupine (wild pea—horse beans), are found growing 
in almost every section of the State and in great abundance on the 
Western Slope, and in many places are cut for hay; they are poison¬ 
ous only at the time of going to seed. Larkspur {Delphinium ), 
is very deadly early in the spring, and loses its toxicity almost en¬ 
tirely at flowering time. The death camas (Zygadenus venenosus), 
growing from a poisonous bulb, is very deadly early in the season, 
but gradually becomes less harmful and dries up in July. Sorghum 
and kaffir corn, which became popular forage crops in the non- 
irrigable sections of eastern Colorado, have produced such dis¬ 
astrous results from feeding green at certain stages of growth 
that their cultivation has been generally abandoned. In Bulletin 
N°* 37 , of the Idaho Experiment Station, is found the following 
bearing upon this subject: “The roots of the wild parsnip or water 
hemlock, which are so virulent in the early spring, have been fed 
to cows in the late summer and early fall without ill effect. An¬ 
other member of the same family, the hemlock water parsnip, has 
a root which is poisonous in the early spring, but harmless after 
midsummer, while the roots of another plant of the carrot family, 
poison hemlock, contain no trace of poison during March, April 
or May, although considerable quantities of the active principle 
coniin are present in the leaves and stems by May. Later in the 
season the roots also become dangerous.” 
2. Unusual Conditions May Affect the Quantity of Poison in 
Plants: In sorghum and Kaffir corn a stunted growth, resulting 
from arid conditions, is best suited for the development of prussic 
acid, the most powerful poison known. The poisoning by Johnson 
grass (a near relative of sorghum), is no doubt due to the same 
cause, as shown by Crawford and by Jeffries. 
The common potato which belongs to the same genus as black 
nightshade, spreading nightshade, bitter sweet, and other dangerous 
plants, contains an active alkaloid solanine which develops in 
large quantities when potatoes become green from exposure to the 
sun. This is no doubt the cause of the sudden and mysterious 
death of horses in the vicinity of Greeley that had been turned 
into potato fields after digging time, many small potatoes having 
