UNITED STATES DEPARTMENT OF AGRICULTURE 
J\J9*^3L 
BULLETIN No. 365 
Joint contribution from the Bureau of Plant Industry, 
Wm. A. Taylor, Chief, and the Bureau of 
Animal Industry, A. D. Melvin, Chief 
Washington, D. C. 
PROFESSIONAL PAPER 
September 8, 1916 
LARKSPUR POISONING OF LIVE STOCK. 
By C. Dwight Maesh and A. B. Clawson, Physiologists, Poisonous Plant 
Investigations, Bureau of Plant Industry, smd Hadleigh Maesh, Veterinary 
Inspector, Bureau of Animal Industry. 
Introductory: 
Historical summary and review of litera- 
ture 
The alkaloids of delphiniums 
CONT] 
Page. 
1 
8 
11 
13 
14 
16 
28 
29 
29 
52 
55 
ENTS. 
Results and conclusions: 
Animals affected by larkspur poisoning.. 
Symptoms of larkspur poisoning 
The toxic dose of larkspur 
Page. 
59 
61 
66 
Post-mortem features of larkspur poison- 
ing...... 
Toxicity of different parts of the plant. . . 
Age of plants affecting toxicity 
Species of delphinium concerned in lark- 
73 
74 
75 
Detection of larkspur species in stomach 
contents 
Treatment of cases of larkspur poisoning. 
Methods of prevention 
77 
82 
Experimental work: 
The station at Mount Carbon, Colo 
The station at Greycliff , Mont 
General summary 
Literature cited in this paper 
Index to species of plants 
84 
87 
91 
Index to experimental feeding of animals. . . 
91 
PART I.— INTRODUCTORY. 
HISTORICAL SUMMARY AND REVIEW OF LITERATURE. 
There is somewhat extensive literature in regard to the larkspurs. 
In this summary and review only the more important and significant 
publications are noted, with especial reference to those that treat of 
the poisoning of domestic animals. 
The larkspurs have been known from very ancient times as 
poisonous and medicinal plants. Under the names crawls aypLa of 
Dioscorides and Hippocrates, ayporepn crawls of Nicander, Astaphis 
agria or Staphis of Pliny, and Herb a pedicularia of Scribonius 
Largus, was probably recognized the species Delphinium staphisagria 
L. Under the name Consolida regalis were probably included several 
species. The question of the identity of the species noted by the 
ancients is discussed in some detail by Huth, 1895, pages 325 and 
326. 1 • 
1 Full titles of articles referred to in the text are given in the list of literature at the 
end of the paper. 
26876°— Bull. 365—16 1 
