184 WEEDS OF THE FARM AND GARDEN 



The western wall flower (E. asperum) is frequently cul- 

 tivated as an ornamental plant. 



Horse-radish (Radicula Armoracia, (L.) Robinson). 

 A stout perennial with long, deep roots ; leaves large, 

 oblong, crenate or pinnatifid, the latter form occurring in 

 the spring; stem leaves lanceolate, or oblong-cordate; 

 flowers having four green sepals and four white petals ; 

 seed seldom found in the pods, which are short and globu- 

 lar. A native of Europe and introduced into this country 

 as a root furnishing a valuable condiment; but in many 

 places it has escaped from cultivation and become a per- 

 nicious weed. When it has once become established, it 

 is very persistent, being one of the most difficult of weeds 

 to remove. 



\ Winter Cress (Barbarea vulgaris, R. Br.). A biennial, 

 one to two feet high, stem furrowed, either simple or 

 branched ; lower leaves simple or pinnately parted, termi- 

 nal lobe the largest, round or ovate ; upper leaves obovate, 

 cut, toothed or pinnatifid at the base ; flowers bright yel- 

 low; pods erect or slightly spreading; cotyledons 

 accumbent. Labrador, New England, New York, Penn- 

 sylvania, Maryland, Wisconsin, Minnesota, Iowa, Man- 

 itoba, British Columbia, mountains of Colorado, Pacific 

 slope southward to Lower California. A native of Europe 

 and Asia. Nearly a cosmopolitan weed, occurring also in 

 Africa and Australia. 



Caper Family (Capparidaceae). Herbs, shrubs or, oc- 

 casionally, trees ; alternate leaves and cruciform flowers ; 

 sepals four to eight ; petals four or none ; stamens six to 

 numerous, not tetradynamous ; fruit a one-celled pod or 

 berry with two parietal placentae; seeds similar to those 

 of the Cruciferse, but with the embryo coiled. 



Stinkweed or Rocky Mountain Bee Plant (Cleome ser- 

 rulata, Pursh). A glabrous annual, leaves three-foliate 

 with bracts among the flowers, leaves and stem emit a pun- 

 gent odor; flowers in racemes, rose-colored; petals entire 



