184 CEUCIFERAE (MUSTARD FAMILY) 



without partitions, being stuffed with a spongy substance be- 

 tween the seeds, which are larger than Mustard seed and brown. 

 Because its rather thick-textured leaves are so nearly smooth, this 

 weed is more resistant to injury from sprays than other wild 

 Mustards and it must be fought in other ways. (Fig. 127.) 



Means of control 



Cut the tufted leaves of autumn plants from their roots with hoe 

 or spud, the latter tool being preferable in grain fields. Spring seed- 

 lings may be raked from the fields with a weeding harrow when the 

 grain is but a few inches tall. Plants that spud, hoe, and harrow 

 have missed, should be hand-pulled in their first bloom rather than 

 be allowed to foul the ground with their long-lived seeds. Where 

 seed has entered the soil, give stubbles surface cultivation after 

 harvest, in order to stimulate germination, and then disk the ground 

 about once in two weeks, so as to kill the weeds while they are 

 tender. 



CHARLOCK OR WILD MUSTARD 



Brdssica arvensis, Ktze. 

 (Brdssica sinapistrum, Boiss) 



Other English names: Kedluek, Skellick, Herrick, Field Kale. 



Introduced. Annual. Propagates by seeds. 



Time of bloom: May to September. 



Seed-time: June to October. 



Range: Throughout North America except the extreme North. 



Habitat: Grain and clover fields, meadows, waste places. 



A very noxious weed because of its immense productiveness 

 more than fifteen thousand seeds having been taken from a single 

 thrifty plant and also because of the exceedingly long vitality of 

 the seed when in the soil. 



Stem one to three feet tall, erect, branching toward the top, 

 roughened with short, stiff hairs. Lower leaves pinnatifid, with 

 the terminal lobe large, and the few lateral lobes small, the petioles 

 rather stout and short ; upper leaves narrowly rhombic, sessile or 

 nearly so ; all irregularly toothed and somewhat hairy ; small 

 blotches of brownish red show on the stem at the junction with the 

 leaves. Flowers in racemose clusters at the ends of stem and 



