POISONOUS AND INJURIOUS WEEDS 115 



weed is not merely unpleasant but dangerous, and cases of 

 human and stock poisoning have been known to occur. Adam J 

 states that the seeds possess a very intoxicating quality and 

 bring on convulsions if taken in large quantities, and in France 

 darnel is called Ivraie because when brewed with barley it 

 acts as a narcotic intoxicant 2 



Melilot (Melilotus spp.} occasionally occurs as a weed in this 

 country, though in America and elsewhere it is grown for 

 fodder. Ewart 3 states that the sweet smelling cumarin, 

 which all the species contain, in excess produces a disinclina- 

 tion to locomotion, paralysis and ultimately fatal symptoms, 

 but that no harm is likely to occur if the amount of melilot 

 present does not exceed 10 per cent, of the herbage. Accord- 

 ing to Adam, 4 if the seeds are ground with the corn they spoil 

 the flour, as the bread made from it has a strong taste and 

 smells like melilot plaister. 



Pennycress or stinkweed (Thlaspi arvense). Complaints of 

 this weed are not often heard in this country, because it seldom 

 happens that it is abundant enough to work harm, but in the 

 Dominions it is regarded as most noxious and special measures 

 are adopted against it. The whole plant has a peculiarly 

 objectionable odour, somewhat resembling that of garlic, and 

 the seed is very pungent. The stinkweed taints milk and 

 butter and also the flesh of animals that eat it, causing con- 

 siderable loss where the weed is plentiful. 5 



Various other weeds are accused of tainting milk and 

 butter, but the evidence in many cases is less clear, and pos- 

 sibly local conditions of soil and climate may make a species 

 harmful in some cases and innocuous in others. Among the 

 accused weeds are buttercups, wild mustard and charlock, 6 

 yarrow, dog daisy, chamomile and mayweed, 7 while woodwax 

 (Genista tinctorid] is supposed to make milk bitter. 



The hooked fruits or burs of various weeds when abundant 

 are another source of loss to the farmer. These burs stick 

 to the wool of sheep as the animals rub against them, and 

 it is impossible to extricate them from the fleeces without 



1 Adam, J. (1789), loc. cit., p. 188. 



2 Long, H. C. (1917), loc. cit., p. 83. 



3 Ewart, A. J. (1909), loc. cit., p. 23. 



4 Adam, J. (1789), loc. cit., p. 192. 



5 Henderson, T. B. R. (1909), " Stinkweed, How ,to Hold it in Check," 

 Press Bull. No. 2, Province of Alberta, Depart, of Agric. 



6 F. M. (1910), " Crucifers and Milk," Revue Scientifique, p. 599. 



7 Long, H. C. (1917), loc. cit., p. 101. 



8* 



