770 



MANUAL OF POISONOUS PLANTS 



obstruct the intestines and prove fatal. In these cases, death is evidently not from any poison- 

 ous quality of the hay, but is due to mechanical causes. While Cocklebur may not be poison- 

 ous, it may in a similar manner kill swine by mechanical obstructions. When the burs are 

 ripe, they readily leave the plant, and attach themselves to the coat of any passing animal. 

 The plant is especially annoying to sheep owners, as these burs become entagled in the wool. 

 Those who have traveled in Texas and Mexico, soon make acquaintance with the cockle bur. 

 Horses and mules, while grazing for a single night, will have their tails clotted with these 

 burs, and converted into a useless club. It can be understood, that if swine eat the burs in 

 considerable quantity, the pieces of them can, by means of the prickles, form masses which 

 may prove fatal. Both on account of its probable danger to swine and its injury to sheep, there 

 should be an united effort to destroy the plant. Being an annual, its extermination would 

 not be difficult. If the plants are cut down before the seed is ripe, new ones can not appear 

 unless the ground is re-seeded. 



Fig. 447. Boneset (Eupator- 

 iiint urticae folium). A common 

 plant in woods. It is supposed 

 by some to cause milk fever or 

 trembles. Branches with numer- 

 ous small heads. (Lois Pam- 

 mel.) 



8. Enpatorium (Tourn.) L. Boneset 



Erect perennial herbs with opposite, whorled or alternate leaves, often 

 sprinkled with resinous dots ; flowers in corymbose heads, white, bluish, or pur- 

 ple ; bracts of the involucre in two series ; receptacle naked ; corolla regular, 

 tube short 5-lobed ; branches of the style slender, thickened upward or club- 

 shaped, very minutely and uniformly pubescent, with stigmatic lines indistinct; 

 achenes 5-angled, truncate ; pappus of numerous fine capillary bristles, arranged 

 in one row. 



About 450 species in warm temperate and tropical regions. An oil is made 

 from the southern . capillifolium, which has an aromatic, pepper-like odor. 



