108 FARM WEEDS OF CANADA 



Black Medick {Medicago lupulina L.), also called Yellow 

 Trefoil, is a useful pasture forage plant and in Europe the seed 

 is frequently sown with mixtures of pasture grasses. The 

 seed is common in clover seeds. It is sometimes mixed with 

 alfalfa and red clover seeds as an adulterant when the latter 

 are high in price. Mixed with red clover or alsike it should 

 be treated as a weed, inasmuch as the plant matures earlier and 

 the stems are hard and woody when the clover is ready to 

 cut for hay. It has little value except as a pasture plant. 



The seed-pods of a few members of the Pea family develop 

 into burs and stick to wool, as, for instance, the Spotted and 

 Toothed Medicks (Medicago arabica Huds. and Medicago hispida 

 Gaertn.), neither of which, however, has established itself 

 firmly in Canada. The only plant of the Pea family giving 

 trouble in this way is Wild Liquorice (Glycyrrhiza lepidota 

 (Nutt.) Pursh) which occurs on the prairies. 



Loco Weed (Oxytropis Lamherti Pursh.) differs from the 

 Milk Vetches (Astragalus) of the western plains in that 

 the keel of the flower is tipped with a sharp-pointed appendage. 

 All varieties of Loco Weed are common on the plains of Alberta 

 and Saskatchewan and are believed to be the cause of a peculiar 

 mental disorder among horses and cattle. 



WILD TARE (Vicia angustijolia (L.) Reichard) 

 Other English names: Wild Pea, Wild Vetch. 



Introduced from Europe. Annual, hairless or downy. Stem 

 slender, simple or branched at the base. Leaves are composed 

 of 2-5, rarely 6, pairs of linear or lance-shaped leaflets. Flowers 

 1/2 to 3/4 inch long, purple, 1 or 2 in the upper axils of the leaves. 

 Pods black and linear, with the tips sharp and turned upwards, 

 2 inches long, 4 to 12-seeded. 



The seed (Plate 74, fig. 48) is round, ranging from 1/10 to 1/6 

 of an inch in diameter, velvety black or olive brown, mottled 

 with white and dotted with fine black spots; the whitish scar 



