188 CRUCIFERAE (MUSTARD FAMILY) 
Stems two to seven feet tall, or even 
more in warm southern soil, branching 
widely, sometimes hairy near the base 
but usually smooth above. Lower leaves 
pinnatifid, with the terminal lobe very 
large and the several lateral lobes small, 
toothed all around, with a long, slim 
petiole; upper leaves less divided, becom- 
ing lance-shaped and nearly sessile at the 
top. Flowers bright yellow, a little more 
than a quarter-inch broad. This plant 
~ is often confused with Charlock, or Wild 
Mustard, but the difference between the 
fruits readily distinguishes them: Char- 
lock has long, knotted or wavy pods, with 
stout, two-edged beaks, while Black Mus- 
tard has short, smooth, four-angled pods, 
a half-inch to an inch long, with short, 
slim beaks; and they are held closely 
pressed to the stalk, making the raceme 
veryslender. Seeds globular, almost black, 
very pungent to the taste. (Fig. 131.) 
Means of control the same as for.Charlock. 
Fic. 131. — Black Mustard 
(Brassica nigra). 
SAND ROCKET 
Diplotdéxis murdlis, DC. 
Introduced. Annual or biennial. Propagates by seeds. 
Time of bloom: June to August. 
Seed-time: July to September. 
Range: Nova Scotia to New Jersey and Pennsylvania, westward to 
Michigan. 
Habitat: Fields and waste places. 
Not a common weed in this country as yet, but Professor Beal 
reports that wherever found in Michigan, it “thrives and spreads at 
an alarming pace.” 
Stem one to two feet high, smooth or sparsely set with bristly 
hairs, branching from the base, leafy only below. Leaves oblong to 
