55 



Character. — The whole plant, especially the flower, is bitter and more 

 or less acrid and pungent. The powdered plant causes violent sneezing 

 when inhaled, and it is therefore used in medicine to produce that effect. 

 Sheep, cattle, and horses that are unfamiliar with the plant are often 

 poisoned by it when driven to localities where it is abundant. As a 

 rule these animals avoid it, but it is said that they sometimes develop 

 a taste for it and are quickly killed by eating it in large quantity. 



Poisonous constituent. — The poi- 

 sonous constituent has not been 

 closely investigated, but it is known 

 that it exists principally in the 

 flowers. The young plants appear 

 to be only very slightly dangerous. 

 In the mature ones the amount 

 of poison present seems to vary 

 greatly even in the same field. 



Symptoms and remedy. — The 

 symptoms, as determined by ex- 

 periments made in Mississippi 

 upon calves, are an accelerated 

 pulse, difficult breathing, stagger- 

 ing, and extreme sensitiveness to 

 the touch. In fatal cases, death is 

 preceded by spasms and convul- 

 sions. Melted lard has been used 

 with good effect in offsetting the 

 action of the poison when given 

 before the spasms began. 



Sneezeweed may be best kept 

 in check by cultivating the ground 

 or by mowing the plants down 

 before the time of flowering. 



Over twenty kinds of sneeze- 

 weed occur in the United States, 

 but only one additional species is strongly suspected of poisoning 

 animals in the field. This is the bitterweed of the Gulf States (H. 

 tenuifolium). One instance is recorded where several individuals were 

 poisoned by eating bread contaminated with its seeds. These were 

 thrashed with the wheat in which the plants were .growing, and were 

 not removed therefrom before its being converted into flour. The 

 plant is conceded by many to be an indirect source of bitter milk and 

 bitter meat in cases where cattle have fed upon it. 



Fig. 34. 



SDeezeweed (Selenium autumnale), o-ie- 

 third natural size. 



