DESCRIPTIVE MANUAL 



147 



Fig. 83-A. Distribution of Small Peppergrass. 



brown, elongated, with prominent ridge on one side, becoming muci- 

 laginous when moistened with water ; cotyledons incumbent. 



Distribution. — Small peppergrass is common in the northern 

 states from New England across the continent; apparently native 

 in the west ; in the east introduced from Europe. It is abundant in 

 fields and waste places. In some years it is particularly common in 

 timothy and clover meadows. 



Extermination. — The peppergrasses are not difficult to extermin- 

 ate in cultivated fields since they are annuals. In growing timothy 

 seed it is important above all to have a field as clean from weeds 

 as possible. Timothy should therefore be sown in a field that has 

 been under thorough and clean cultivation for several years and 

 clean seed only should be used. In this way the peppergrass can 

 largely be prevented from growing. 



Fletcher and Clark make the following suggestions: "Only 

 autumn plants which live through the winter give trouble in grain. 

 Thorough surface cultivation in the spring, with the plow, disc or 

 broad-shared cultivator, is efficacious. Immature seeds may ripen 

 in the pods when plowed down. ' ' 



Hoary Alyssum (Berteroaincana (L.) DC). 



Description. — A tall, green, erect annual or biennial with entire, 

 pubescent, pale green, lanceolate leaves; flowers white, 2-parted; 

 pods canescent. 



