THE DICOTYLEDONES 



1639 



napiis to the Swede; Brassica {Sinapis) alba is White Mustard and B. nigra 

 is Black Mustard. 



Turning to other genera of economic importance we may mention: 

 Lepidium sativum (Cress), Cochlearia armoracia (Horseradish), Raphanus 

 sativus (Radish), Crambe niarititna (Seakale) and Nasturtium officinale 

 (Watercress). 



Fig. 1501. — Cheiranthiis cheiri. The Wallflower. 



Common garden plants include: Matthiola (Stocks); Cheiranthus (Wall- 

 flower) (Fig. 1 501); Hesperis (Dames' Rocket) (Fig. 1502); Alyssum (Sweet 

 Alyssum); Aubrieiia; Iberis (Candytuft); Lunaria (Honesty); and Arabis 

 (Rock Cress). 



Fig. 1502. — Hesperis matronaJis. Dames' Rocket. 



Many are common weeds, such as Capsella bursa-pastoris (Shepherd's 

 Purse) ; Brassica arvensis (Charlock) ; Cardamine hirsuta (Hairy Bitter Cress) ; 



