6 BULLETIN 365, U. S. DEPARTMENT OF AGRICULTURE. 
S. B. Nelson, in 1906, performed a series of experiments, feeding 
Delphinium menziesii D. C. and D. simplex Doug. Eight experiments 
were made with Delphinium menziesii) consisting of the direct feed- 
ing of both mature and immature plants, and of hypodermic injec- 
tions of alcoholic and chloroform extracts. As much as 26 pounds 
of this plant, gathered in full bloom, was fed and apparently 3 
pounds and 10 ounces of Delphinium simplex. All of these experi- 
ments were without results and he reached the definite conclusion 
that Delphinium menziesii is not poisonous to sheep and therefore 
that they may be allowed to graze where this plant grows in abun- 
dance without any fear of loss. 
Glover, 1906, gives a somewhat extended description of the lark- 
spurs as poisonous plants. He finds that five species of larkspur 
are abundant in Colorado — Delphinium nelsonii Greene, D. elonga- 
tum Rydb., D. geyeri Greene, D. harbeyi Huth, and D. penardii 
Huth. He made an attempt to get exact information from the 
stockmen of Colorado in regard to their losses and the remedies 
used, and summarized the results obtained from the circulars sent 
out. He describes in some detail the appearance of the larkspurs, the 
symptoms of poisoning, and discusses the best methods of treatment. 
He says: 
From the reports in other Western States, especially Montana, it would seem 
that the purple larkspur which is more generally eaten by sheep is the more 
disastrous of the two. In this State it is quite the reverse. The tall larkspur 
is more abundant and the major part of the mortality is among cattle. 
It would seem from this that Dr. Glover does not question the 
fact that sheep may be poisoned by eating larkspur. The same thing 
is indicated by his giving the symptoms of larkspur poisoning in 
sheep, page 23. He summarizes the conclusions obtained in regard 
to larkspur poisoning, as follows, page 18 : 
First. At least 18 species, and several varieties of larkspur, have been found 
growing in the State. Four growing in the greatest abundance are known to 
contain an active poison in sufficient quantities to be dangerous to live stock. 
Second. Death is produced as a result of the presence of an active poison, 
and not from " bloat," as many stockmen have claimed. 
Third. The toxic principle of larkspur has not yet been determined for these 
species, but is probably delphinin and allied alkaloids present in other species 
that have not been fully studied. 
Fourth. The plant loses its toxic qualities as it approaches the flowering sea- 
son and finally becomes harmless. 
Fifth. Two species, because of their abundance, are doing most of the damage, 
i. e., tall larkspur (Delphinium elongatum) and purple larkspur {Delphinium 
nelsonii). 
Sixth. Stockmen generally have little knowledge of the identity, poisonous 
nature, or satisfactory remedy for larkspur. 
Seventh. Considering the enormous loss and the fact that larkspur is usually 
found in circumscribed areas, it would seem feasible, in many localities at 
least, to undertake its eradication by the grubbing hoe. 
