THE SUNFLOWER FAMILY 161 



Injury: This weed causes a curious and fatal disease of the 

 liver (hepatic cirrhosis) in cattle. For many years it was sus- 

 pected that Ragwort was the cause of this malady, and this 

 has recently been conclusively proved by experiments carried 

 out by Dr. W. H. Pethick, of Antigonish, under the direction 

 of the Dominion Veterinary Director General, Dr. J. G. Ruther- 

 ford. The disease, previously supposed to be contagious, has 

 been removed from the list dealt with under the Animal Con- 

 tagious Diseases Act. 



Remedy: Every effort should be made to eradicate this 

 coarse, conspicuous and dangerous plant, now that there is proof 

 of its nature. It does not increase extensively from the root 

 and there is good evidence that where it is mowed systematically 

 it soon disappears. In pastures and meadows every plant should 

 be grubbed out before the seeds form. Ragwort is not readily 

 eaten by cattle when green: the first attention should therefore 

 be given to cleaning meadows, because it is eaten by all kinds 

 of stock when mixed with hay. A short rotation of crops would 

 at once exterminate it. Sheep can eat this weed with com- 

 parative impunity and it dies out when closely eaten off. System- 

 atic and combined effort should be made by municipal authorities 

 to have it destroyed along roadsides. 



ALLIED SPECIES: Common Groundsel (Senecio vulgaris L.) 

 has been introduced from Europe and is now found in gardens, 

 rather rarely in Ontario and Quebec and the Prairie Prov- 

 inces but abundantly in the Maritime Pro^'^nces and on the 

 Pacific Coast. It is a small, branching plant, 6 to 8 inches high, 

 bearing many tassel-like rayless flowers. The seed is long 

 and narrow, spindle-shaped, the upper end blunt and slightly 

 enlarged by the white apical scar; surface finely ridged length- 

 wise, and covered with short white bristles, differing in this 

 from the seed of the similar Stinking Groundsel (Senecio viscosits 

 L.) which occurs in the Maritime Provinces with Common 

 Groundsel. Stinking Groundsel is viscid-hairy, its flower heads 

 bear marginal ray-florets, and the seed is rather long, entirely 

 without bristles. 



