B. P. 1.—329. 
MISCELLANEOUS PAPERS, 
i LARKSPURS AS POISONOUS PLANIS”. 
By ALBertT C. CrawForp, Pharmacologist, Poisonous-Plant Investigations. 
INTRODUCTION. 
Throughout the United States many species of larkspur (Delphin- 
ium) occur. Some of these form an important feature of the western 
landscape; ° others, such as Delphiniwm ajacis, on account of their 
beauty have been cultivated in gardens, from whence they have 
escaped and become a pest to the farmer.°¢ 
The genus Delphinium is in a very confused condition botanically 
and needs revision.? However, the botanical characteristics of the 
genus are clearly marked and constitute sufficient reason for consider- 
ing any plant bearing them as deserving of suspicion. Delphiniwm 
trollufolium Gray, represented in the accompanying illustration 
(Plate I), shows these characteristics. In Canada? and in our West- 
ern States, especially in Colorado and Montana, various species of 
Delphinium have been accused of stock poisoning, although feeding 
experiments with these plants have varied in their results, and opinion 
in the West has been by no means uniform as to their poisonous prop-- 
erties. According to Wilcox,’ in Montana 600 sheep were poisoned by 
Delphinium menziesii on one ranch, of which 250 died. In India the 
a@Of the many kinds of plants of the western ranges poisonous to stock, vari- 
ous species of larkspur are among the most destructive, especially in the moun- 
tainous regions of Colorado, Wyoming, and Montana. 
About two years ago a study of the poisonous properties of one of the most 
common species was undertaken cooperatively by the Colorado Agricultural 
Experiment Station and the Office of Poisonous-Plant Investigations, the field 
collections and field tests being carried on by Dr. George H. Glover, veterinarian 
of the station, and the technical laboratory studies by Dr. A. C. Crawford, 
Pharmacologist, under the direction of Dr. R. H. True, Physiologist in Charge 
of the Poisonous-Plant Investigations of the Bureau of Plant Industry. The 
principal results of Doctor Crawford’s work are here summarized. 
It is shown that this larkspur is most virulent in its early stages and becomes 
much less active toward flowering time. The importance of the functions of 
elimination in bringing about recovery is also clearly indicated, and the signifi- 
eance of this fact in harmonizing the varying results of different investigations 
is pointed out.—B. T. GaLLoway, Chief of Bureau. 
’ Meehan, T. Delphinium Bicolor. Meehan’s Monthly, vol, 12, p. 1. 1902. 
¢ Rept. Comr. Agr. for 1865, p. 510. 
@ Huth, E. Monographie d. Gattung Delphinium. Bot. Jahrb., vol. 20, p. 322. 
1895. 
€ Noxious Weeds and How to Destroy Them. Government of Northwest Ter- 
ritory, Dept. Agr. Bul. 2, p. 27. 1900. 
?f Chesnut, V. K. Preliminary Catalogue of Plants Poisonous to Stock. Ann. 
Rept. Bur. Animal Ind., 1898, p. 400. 
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