-CLASS I. NUTRITIOUS ROOTS. 863 



25. SWEET POTATOES, or CAROLINA POTATO. Con- 



volvulus batatas. 



A tender perennial plant, a low, creeping vine, a native of the 

 Southern States. The roots are long tubers, of a white or red color ; 

 when boiled, baked, or roasted, they are of a sweet, agreeable taste, 

 and form a nourishing and wholesome food. It is raised from slips 

 of the roots. The sweet potato is often cultivated as far north as 

 Boston ; the slips are usually procured from New Jersey, as they are 

 difficult to preserve, except in dry, warm chambers, secure from frost. 

 These are placed vertically in a hot-bed in April. When sprouted, 

 they are transplanted to the open field, in a dry, warm situation, tou 

 sandy, but well-manured soil ; they are placed in elevated hills, six 

 feet asunder each way. The vines, as they extend, must not be suf- 

 fered to strike root. 



26. TARO. 



A bulbous-rooted plant, of the genus arum, a native of the valley 

 of the Columbia River. It is planted In hills, and cultivated in the 

 manner of rice, on ground so situated as to be partially flooded 

 with water. It comes to maturity in eight or ten months from the 

 time of planting. To prepare them for food, they are roasted ; they 

 then become a substitute for bread ; or they are made into poi, by 

 pulverizing and converting them to a paste. 



27. TRAPA NATANS. Neill. 



This plant grows in ponds, and is eaten like the chestnut. The 

 -canal of Versailles is covered with the plant, and the xoot is some- 

 times served up at table. 



28. TURNIP. Brassica rapa. 

 A hardy biennial plant. 



1. Early White Dutch. 5. Yellow Stone. 



2. Early Stone. 6. Yellow Maltese. 



3. White Flat. 7. Long Yellow French. 



4. Largji English Norfolk. 8. Yellow Aberdeen. 



9. Ruta Baga, Russian, or Yelloio Swedish. 



Turnips may be sown broadcast ; very early for the early crop ; 

 as late -as midsummer for the late or main crop ; or, they may be 

 sown in rows at distances proportioned to their sizes. No. 1 is es- 

 teemed the best for an early crop. Nos. 5, 6, and 8 9 are new varie- 

 ties, of superior quality, of a rich taste, and fine for keeping. No. 9 

 is also of a fine, rich quality, retaining all its goodness to a late period 

 in spring. This kind produces enormous crops, and is a valuable 

 article of winter food for cattle. No. 7 is a very superior new kind, 

 from Teltow, near Brandenburg, of small and slender form ; those 

 sown at midsummer keep till spring, and are of great excellence, 

 whether stewed, or coo'ked by other modes. The best for the table 

 are raised in poor ground ; some have a skin of a coal black color. 



29. WAPPATOO. Sagitlifolia. 



A tmlbous root, a new species of the arrowhead, which is found 

 only in the valley of the Columbia River, below the Cascades. It 

 grows in shallow lakes, and in marshes covered with water. When 

 roasted, it becomes soft, and is then both a palatable and nourishing 



