XV 



ROOT CROPS 



I. BEETS 



342. Name. The term "root crops" is used to apply rather 

 loosely to a class of plants, mostly biennials, in which the food 

 supply is usually stored up the first season in the thickened 

 stem (hypocotyl) and primary root as nourishment for the 

 fruiting stem the second season. With regard to duration, how- 

 ever, there are exceptions, rape being an annual. Even in a 

 single species, such as the beet, individual plants may be found 

 that are annual, and others that are perennial. In some in- 

 stances, as in the common cabbage, the food supply is stored 

 up in the leaves, while in kohlrabi it is stored in the stem alone. 

 Custom varies as to the use of the term "root crop" to apply 

 to all these plants, but since they all have similar adaptation 

 and uses, and require somewhat similar cultural methods, they 

 are treated together in this chapter under the general term of 

 root crops. 



343. Relationships. Root crops belong to several genera, of 

 which the following are most widely known : ( I ) Beta, including 

 garden beets, sugar beets, and mangel-wurzels ; (2) Brassica, 

 including turnips, rutabagas, kohlrabi, cabbages, rape, and kale ; 

 (3) Daucus, including the carrot, and (4) Pastinaca, which 

 includes the parsnip. The carrot and the parsnip both belong 

 to the carrot family (Umbelliferae) , which includes celery, 

 parsley, and caraway, and also a number of disagreeable weeds, 

 among which are the wild forms of carrot and parsnip. 



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