186 CRUCIFERAE (MUSTARD FAMILY) 
A special pest in grain fields, as its early season of bloom enables 
it to foul the ground with its seeds before the grain is ready to 
harvest and the smooth, glaucous foliage renders it impervious to 
injury from sprays that would not also kill the accompanying crop. 
Fic. 129. — Indian 
Mustard (Brassica 
juncea). xX}. 
Stem one to four feet tall, erect, rather 
stout, with few branches. Lower leaves 
pinnatifid, with terminal lobe very large, 
coarsely toothed, and with long petioles; 
upper leaves oblong, nearly entire, tapering 
to the base, all light green, rather thick, 
smooth, and glaucous. Flowers bright yellow, 
more than a half-inch broad, clustered at 
the top of racemes, which, before the pods 
are all formed, often become more than 
a foot long. Siliques one to two inches 
long, nearly a third of their length taken 
by a slim, awl-shaped, empty beak. Seeds 
globular and brown. (Fig. 129.) 
Means of control 
Harrow young seedlings from grain fields 
with a weeding harrow. Plants that survive 
the treatment should be hand-pulled while 
in early bloom. If seeds have matured and 
fallen, stubbles should be burned over for 
the purpose of destroying them. Plants of 
roadsides and waste places should also be 
pulled or cut before seed is formed. 
WHITE MUSTARD 
Brdssica dlba, Boiss 
(Sindpis dlba, L.) 
Introduced. Annual or biennial. Propagates by seeds. 
Time of bloom: June to August. 
Seed-time: July to September. . 
Range: Locally in most parts of North America except the far 
North. 
Habitat: Cultivated ground, waste places. 
