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WEEDS OF THE FARM AND GARDEN 



inches long, irregular in outline, appearing somewhat 

 knotty, three to seven-seeded or more, the upper part of 

 the pod forming a beak; seeds round, darker than those 

 of the black mustard and minutely pitted, mucilaginous 

 when moistened. Very common in all parts of Iowa, and 



the Northwest and Canada. In 

 some places, during July and 

 August, the streets are fairly yel- 

 low with it and many fields con- 

 tain a larger per cent of mustard 

 than of grain. 



Black Mustard (Brassica nigra, 

 (L.) Koch). Black mustard is a 

 tall, coarse, much-branched an- 

 nual, growing from two to five 

 feet tall, with leaves variously 

 divided or deeply cut, the terminal 

 lobe being the largest, sharply 

 toothed ; the upper leaves small, 

 simple, and, as a rule, linear; 

 leaves somewhat bristly, at least 

 on the veins ; flowers yellow, 

 smaller than those of charlock; 

 pods smooth, about one-half inch 

 long, four-cornered, tipped with a 

 slender beak. This weed is very 

 common in all parts of the North, 

 having been reported from many different localities. It 

 prefers rather rich soil. 



Hare's Ear Mustard (Conringia orientalis, (L.) Du- 

 mort). An erect, glabrous annual herb, with elliptical or 

 ovate, entire, sessile, cordate leaves ; flowers yel- 

 lowish white in racemes, elongating in fruit; petals and 

 sepals narrow; silique elongated, linear, four-angled. In 

 waste places and grain fields in the Northwest, ako in 

 the East. 



Fig. 1 1 6. Common mus- 

 tard (Brassica nigra). 



