41 



The low larkspurs are poisonous during the whole season of their 

 growth, but as they dry up and disappear in the early summer, poisoning 

 usually occurs in the early spring. 



The tall species live throughout the summer, but their toxicity dimin- 

 ishes after they flower, and they become coarse and less tempting. There- 

 fore, although the seeds are very toxic, cases of poisoning occur chiefly 

 in the spring when the green parts of the plant are most poisonous and 

 afford an abundance, of fresh green. In regard to the seeds, H. C. Long 

 says they "are the most dangerous part of the larkspur, and should never 

 be ground up with wheat should the two plants grow together." The loss 

 of three head of cattle was reported to us (1918) from Barrhead, Alta., 

 from eating the seed vessels of larkspur containing seeds. These had been 

 cut and dried with the hay. 



Animals Affected: In the feeding experiments mentioned above, 

 it was shown that the larkspurs were poisonous to cattle and horses but 

 not to sheep. Horses, under ordinary conditions, do not eat sufficient 

 quantity to do harm, so that losses from larkspur poisoning are chiefly 

 confined to cattle. Pott states that D. Consolida is an acute narcotic 

 poison to horses and cattle. 



Symptoms: The general symptoms of poisoning both from the tall 

 and the low larkspurs are as follows: salivation, nausea, vomiting, weak- 

 ness, colic, twitching of the muscles of the sides and legs, convulsions, and 

 general paralysis. If the animal does not recover, death usually occurs 

 in a few minutes or a few hours. 



Remedy and Means of Control : Marsh and Clawson found in their 

 experiments with "Antidotes that beneficial results were obtained by using 

 **hypodermically, injections of physostigmin salicylate, pilocarpin hydro- 

 chlorid, and strychnin sulphate, followed by hypodermic injections of 

 whisky when needed. '* 



They also pointed out that "if in the beginning of the poisoning some 

 remedy could be used which would quickly stimulate the intestinal excre- 

 tion, it might serve to save the lives of animals." 



As regards the eradication of larkspur, choice of methods must depend 

 entirely upon conditions and circumstances. It may be pointed out that 

 the loss of a single steer will cover a large amount of the cost of grubbing 

 out' this weed. The yearly loss of several head of cattle on a single farm 

 and the cost of destroying the weed is best calculated by the owner. 

 Where entire extermination is impossible, the first year or two, the number 

 of the plants may be so reduced as to avoid actual loss by poisoning. In 

 most cases the surest means of killing the plant is to cut off the roots from 

 six to eight inches below the surface of the soil. The work should be done 

 thoroughly to prevent the growth of new shoots. All tops cut off should 

 be destroyed at once. 



