156 PLANTS AND MAN 



Europe and western Asia, the turnip has become a cool-season 

 crop throughout temperate regions. Unlike the beet, the food is 

 stored almost entirely in the xylem portion of the root (fig. 90), 

 outside of which is a small phloem and cortex region. The flesh 

 of turnips varies from white to pale yellow. The cells of the 

 xylem are not lignified like the woody tissues of many plants, 

 hence they are soft and edible. Turnips were introduced into this 

 country by the first settlers to come to Virginia and New Eng- 

 land, early in the seventeenth century. 



The RADISH is characterized at maturity by an elongated 

 though smaller fleshy tap root, similar in general character 

 to the turnip but with more food stored in the slightly larger 



XYL€M CAMBIUM P^^^^"^ region (fig. 91). Radishes 



are still found growing wild in 

 temperate parts of the old world, 

 from which they were brought to 

 this country by the early English 

 settlers. Numerous varieties have 

 been produced with different 

 colors of flesh and pungency of 

 flavor. 



PHLOEM Horseradish has a more cylin- 



FiG. 91.— The radish is similar drical tap root, usually with white 



in general character to the turnip fl^^j^. -^ j^^^ ^^^^ cultivated for 



but has more food in the slightly , . • i- 



1 _i 1 ^„. „ centuries m Europe, its native 



larger phloem region. , , 



home. Unlike radishes, carrots or 

 turnips it is not eaten as a vegetable but more usually made into 

 a condiment after being mixed with vinegar. 



Carrots, commonly found in the wild state over a large 

 portion of the old world, have long been under cultivation in 

 Europe and Asia. In the United States, escaped plants have 

 made themselves at home and become wild flowers as well as 

 troublesome weeds. The cortex and phloem region of a carrot 

 root (fig. 92) is much larger than in the radish or turnip; in it 

 most of the stored food is accumulated. The central xylem portion 

 of a carrot is less nutritious and often becomes woody. Carrots 

 vary considerably in shape, but are characteristically yellow in 

 color due to the presence of the pigment carotin. This is some- 



