184 CRUCIFERAE (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 otber 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 arvénsis, Ktze. 
(Brdssica sinapistrum, Boiss) 
Other English names: Kedluck, 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 
