110 FARM WEEDS OF CANADA 



Hairy or Winter Vetch {Vicia Villosa Roth.) is a cultivated 

 variety, the seed of which closely resembles that of spring vetch. 



The seeds of the above mentioned species are often difficult to 

 identify, owing to their great variation in size, shape and colour. 

 They are common in cereal grain. 



THE SPURGE FAMILY (Euphorbiaceae). 



This family belongs to the flora of tropical and temperate 

 climates and is widely distributed as herbs, shrubs and trees. 

 Those common in Canada are principally low, prostrate weeds, 

 mostly introduced and naturalized. The abundant, milky, 

 acrid juice they contain is a characteristic of the family. This 

 juice acts as an irritant and is poisonous. The plants are seldom 

 attacked by insects or fungus growths. 



Wax-ball or Three-seeded Mercury (Acalypha virginica 

 L.), common in river flats and low fields in Ontario and east- 

 ward, belongs to this family. It is a leafy plant, 1 to 2 feet high, 

 with long-stalked, ovate leaves. It gives trouble in pastures, 

 meadows and fields. On account of its acrid juice it is avoided 

 by live stock and entails considerable waste wherever it 

 occurs. The seed is about 1/16 inch long, yellowish-gray, ovoid 

 in outline, and comparatively soft, sometimes found in clover 

 seeds. Clover fields should be rogued of this weed before the 

 crop is harvested for seed. 



Sun Spurge {Euphorbia Helioscopia L.), introduced, is an 

 erect annual, abundant in eastern Canada. Mode of flower- 

 ing, nearly flat-topped, umbrella-like, surrounded at the base 

 with a whorl of stalkless, obovate, finely and thickly dentate 

 leaves. Pod or capsule smooth and even, 3-lobed. 



The seed (Plate 74, fig. 49) at first sight somewhat resembles 

 the nutlets of plants of the Mint family, or, better, the pods of 

 Ball Mustard in miniature. When examined closely^ however, 

 it is easily recognized. It is rounded-oval in outline, rolling 

 freely on a smooth surface, a little flattened on one face, with 

 a sharp central ridge running to the apex. The sides of the 

 seed not angled, as in those of the Mint family, the whole surface 

 coarsely netted; scar kidney-shaped, white and very conspicuous. 



