CBUCIFERAE (MUSTARD FAMILY} 185 



branches, bright yellow, fragrant, each about a half-inch broad, 



the calyx-lobes spreading ; they begin to open at the bottom of the 



cluster, which lengthens as the season advances and the pods form 



and ripen, so that there may be emptied pods below and forming 



buds above. Silique, or pod, one to two inches 



long, round and somewhat constricted between 



the seeds, veined and ribbed, and tipped with- 



a long, two-edged beak ; it may contain three 



or four to a dozen or more seeds, one of which 



is usually sticking in the beak when the pod 



splits. Seeds globular, dark reddish brown, 



under a lens seen to be delicately pitted. 



They are a common impurity of grass and 



clover seeds. (Fig. 128.) 



Means of control 



In grain fields seedlings should be harrowed 

 out, with one of the light harrows known as 

 weeders, when the grain is but a few inches 

 tall ; or later, but before the grain begins to 

 head, the Mustard may be almost entirely 

 destroyed by the use of Iron sulfate or 

 Copper sulfate spray. Stubbles should be 

 surface-cultivated immediately after harvest 

 in order to stir into growth such seeds as 

 may be lying on the ground; the young 

 plants to be plowed under, or they may 

 be profitably grazed off by sheep. Plants of 

 waste places, fence rows, and roadside should 

 be hand-pulled or closely cut when the flowers FlQ 12g char- 

 are first noticed. lock (Brassica aroen- 



sis), Xi- 



INDIAN MUSTARD 

 Brdssica juncea, Cosson 



Introduced. Annual or biennial. Propagates by seeds. 



Time of bloom : May to July. 



Seed-time: June to August. 



Range: Ontario to Manitoba, southward to Georgia and Kansas. 



Habitat: Grain fields, roadsides, and waste places. 



