26 



prove that a larger quantity would not be dangerous. A stockman 

 very familiar with the plant claims that cows must feed on it for sev- 

 eral hours before they will be affected seriously. This may also be the 

 case with other species. Their comparative poisonous quality has not 

 been studied. The percentage of fatal cases in cattle which have 

 eaten larkspur is said to be small. A rough estimate by a cattleman 

 places it at about 20 per cent for one species of the group, when the 

 animals are not properly treated, and 5 per cent otherwise. This is 

 probably a low estimate, however, for in a case of poisoning from D. 

 menziesii that occurred in Montana in May, 1897, and was reported 

 by Dr. E. V. Wilcox, nearly 600 sheep were affected, 250 of which died. 

 Remedies. — There is a general similarity in the poisonous action of 

 the larkspurs, and this is strikingly like that of aconite or monkshood, 

 which these plants also closely resemble botanically ; further, it has 

 been shown that the characteristic alkaloid of each has about the 

 same behavior. The antidotes to be recommended are, therefore, the 

 same as for aconite poisoning. Atropine was used last year with 

 remarkable success by Dr. Wilcox. Melted lard (or bacon grease) 

 is claimed to be an efficacious remedy in the hands of farmers. It is 

 an excellent precaution to allow animals in pastures containing lark- 

 spur only when well fed, and then only for short periods, until they 

 become thoroughly familiar with the deleterious nature of the plants. 



PLUM FAMILY (PRUNACEAE). 



BLACK CHERRY. 

 Prunus serotina Ehrli. 



Other names: Wild black cherry; wild cherry; rum cherry; whisky 

 cherry. (Fig. 10.) 



Description and habitat. — A valuable forest tree, 60 to 80 feet high, 

 with thin, reddish brown, scaly bark, tapering, saw-edged leaves, 

 cylindrical clusters of small white flowers appearing in April and May, 

 and shining black, edible fruit, about a quarter of an inch in diameter. 

 It grows abundantly in forests in the Middle Atlantic and Ohio Elver 

 States; less commonly in woods and in the open country in the south- 

 ern New England and Gulf States, and westward from Illinois to 

 South Dakota, eastern Nebraska, and Arkansas. As an ornamental 

 and shade tree it is cultivated extensively in Wyoming and Colorado, 

 and eastward to the Atlantic. 



Fruit. — The fruit is rather agreeable, being but slightly bitter and 

 astringent in taste. In some localities it is much used to flavor liquors. 



Causes of poisoning. — Poisoning is frequently caused in cattle by eat- 

 ing the wilted leaves from branches thrown carelessly within their 

 reach or ignorantly offered as food. Children occasionally die from 

 eating the kernels of the seed or by swallowing the fruit whole. The 

 poison is formed in the leaves of detached branches by the chemi- 

 cal action of two nonpoisonous substances which are present in the 



