176 CRUCIFERAE (MUSTARD FAMILY) 
A very few of these seeds ground by accident with a grist of wheat, 
ruins the flour, arid grain that contains them is very sharply cut 
in price. 
Means of control 
Sow clean seed. If the infestation is new, hand-pull and destroy 
all plants before any fruits mature, even though the task be very 
strenuous. In grain fields, if seeds have been allowed to ripen, 
burn over the stubbles for the purpose of destroying those that have 
fallen on the ground. Give surface cultivation in order to encour- 
age germination of such seeds as are in the soil, and plow the young 
plants under while still in the rosette stage of growth. But never 
turn under any plants bearing developed pods, even though they 
may be green, for they go on ripening on the stalks, when under the 
warm soil, quite as well as or better than above it. Autumn- 
grown plants are the most obnoxious, since they come earliest into 
bloom and fruit the next season, and every effort should be made to 
kill as many of these as possible. Spring seedlings may be dragged 
out of grain fields with small-toothed weeding harrows, beginning 
when the grain is only about three inches high and repeating the 
operation once or twice afterwards —a treatment which greatly 
benefits the crop at the same time that it kills the weeds. If 
practicable, put the ground to.a cultivated crop, which should be 
given very thorough tillage, before the land is used again for grain. 
COMMON PEPPERGRASS 
Lepidium virginicum, L. 
Other English names: Tongue Grass, Bird’s Pepper. 
Native. Annual and winter annual. Propagates by seeds. 
Time of bloom: May to September. 
Seed-time: Late June to October. 
Range: Nova Scotia to Minnesota, southward to Florida, Texas, 
and Mexico. 
Habitat: Grain and clover fields, roadsides, and waste places. 
Stem six inches to two feet tall, much branched. The weed 
sometimes becomes a tumbleweed because of this spreading growth. 
