CRUCIFERAE (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 
are first noticed. 
INDIAN MUSTARD 
Brdssica juncea, Cosson 
Fie. 128.— Char- 
lock (Brassica arven- 
sis). XH. 
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. 
