376 



ELEMENTARY STUDIES IN BOTANY 



grown almost exclusively in the southern states, from Vir- 

 ginia around to Texas. The most northern state in which 

 they are grown on a large scale is New 

 Jersey; and fairly large crops are pro- 

 duced in Ohio, Indiana, Illinois, and 

 California. 



Propagation is by means of sprouts that 

 develop from the potatoes when they are 

 planted in propagating beds or frames. 

 These root sprouts are used as slips or 

 cuttings. Sometimes cuttings are also 

 obtained from the tips of fresh runners. 

 The plant is very sensitive to frost, and 

 there is often great loss on account of 

 planting too early. The sprouts are set in 



r WS ab Ut f UI> feet aai>t the kntS in 



FIG. 51.-Sweet potato, 



showing the charac- each row being about 18 inches apart. 



ter of flower and leaf . . . 



A good average yield is said to range 

 from 200 to 400 bushels an acre, and the crop is harvested 

 immediately after the first frost. 



Sweet potatoes are often raised in 

 the northern states on a small scale as a 

 home garden crop. In this case, loose- 

 ness and warmth of soil are secured 

 by planting the slips on ridges of soil. 



84. Parsnip and carrot. These 

 vegetables are the thickened tap-roots 

 (Fig. 52) of two plants belonging to the 

 parsley family (Umbellif erse) . They 

 are introduced here not so much on 

 account of their importance, as to 

 illustrate root crops from another 

 family of plants. The family is a large 

 one, including, along with parsnip and carrot, such well- 

 known forms as coriander, fennel, caraway, hemlock, and 



FIG. 52. Carrot. 



