188 



IMPORTANT FAMILIES OF PLANTS 



mercial importance. They are used in the preparation of foods 

 and also as medicines. Their use antedates the Christian Era. 



FIG. 117. The flat form of true turnip with white flesh. 



Field Turnips (B. campestris) and true turnips (B. rapa) 

 (Fig. 117) are well known plants used for food for both man 

 and beast. They originated . in northern Europe and Asia and 



