CHAPTER X 



CRUCIFERAE 



RAPHANUS SATIVUS 



THE mustard family is large and its members widely distributed. 

 It includes several species of economic importance and numer- 

 ous common weeds. These are chiefly herbaceous with a pungent 

 watery juice, simple alternate leaves that are variously lobed and 

 dissected, and flowers that are regular, perfect, and cruciform. The 

 fruit is a pod-like structure Icnown as a silique which is usually 

 dehiscent. Among the more widely cultivated crucifers are radish, 

 Raphanus sativus L.; cabbage, Brassica oleracea, var. capitata L.; 

 cauliflower, B. oleracea, var. botrytis L.; Brussels sprouts, B. 

 oleracea, var. gemmifera, Zenk.; turnip, B. rapa, L.; mustard, B. 

 nigra (L.) Koch., and B. alba (L.) Boiss.; rape, B. Napus L.; and 

 horseradish, Radicula Armoracia (L.) Robinson. 



GENERAL MORPHOLOGY 



The radish is extensively cultivated as a garden crop and grows 

 as an herbaceous annual or a true biennial in northern climates. 

 It normally produces a fleshy tap root and a rosette of leaves the 

 first year; but, when planted early, may form the flower and fruit 

 the same season. (Fig. 140.) Radishes may be classified on the 

 basis of their time of maturation; and, with respect to seasonal 

 development, there are early or forcing varieties, summer, and win- 

 ter types. The early varieties are the most commonly planted and 

 are often grown in hot beds and greenhouses, frequently reaching 

 marketable size in from 10 to 30 days. The quickly maturing 

 types, including the Scarlet Globe variety upon which the present 

 studies are largely based, remain tender and-succulent for a short 

 time only. Summer radishes require six to eight weeks to mature 

 and are larger than the early types. The winter varieties, which 



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