CULTURAL DIRECTIONS 435 



SWEET POTATO (Ipomoea batatas) 



623. History. There is no definite knowledge of the 

 origin of the sweet potato, although it is believed the 

 plant is native to the West Indies and Central America. 



624. Botany. The sweet potato is perennial, although 

 it is grown as an annual. It belongs to the morning- 

 glory family or Convolvulaceae, the flowers with purplish 

 throats and white margins, resembling those of the 

 morning glory. The blooms are rare and may not pro- 

 duce seed. The trailing vines strike root at the joints 

 and bear leaves which vary greatly in shape, being of 

 three general types, viz., entire and not lobed, shoul- 

 dered and lobed, and deeply cut and lobed. The general 

 form of the leaf is heart-shape or halberd-shape. The 

 tubers are also variable in shape, size and color. Some 

 are long and cylindrical, others short, thick and blunt 

 at the ends. The skin may be whitish, dull straw-color, 

 light red or purple. The flesh is also variable in color, 

 texture, moisture and quality. Classification of varieties 

 is usually based upon the shape of the leaves. 



625. Importance. The sweet potato is one of the most 

 important vegetables grown in the United States. It is 

 consumed in enormous quantities throughout the South, 

 where it is generally grown. The average annual pro- 

 duction in the United States is about 50,000,000 bushels. 

 Every northern market is well supplied during most of 

 the year. The sweet potato is grown much more ex- 

 tensively than the white potato in the southern states, 

 and is a popular vegetable in practically all tropical 

 countries, constituting in many instances an important 

 source of food. The tubers are fried, baked, boiled and 

 braised, and also used for pies like pumpkins. A con- 

 siderable quantity is canned. In some sections the pota- 

 toes are fed to sheep, hogs and cattle. They may become 

 important for the manufacture of denatured alcohol. 



