104 OF THE ROOT, 



first approach of the succeeding winter, nor 

 can any artificial heat preserve them. This is, 

 no doubt, to be attributed to the exhausiion 

 of their vital energy by flowering. Several 

 plants of hot climates, naturally perennial 

 and even shrubby, become annual in our 

 gardens, as the Tropceolum, Garden Nastur- 

 tium. 



In the Turnip, and sometimes the Carrot, 

 Parsnep, &c., the Caudex or body of the 

 root is above-ground and bare, becoming as 

 it were a stem. linnssus indeed calls the 

 stems of trees " roots above-ground ;" but 

 this seems paradoxical and scarcely correct. 

 Perhaps it would be more accurate to say 

 the caudex is a subterraneous stem ; but we 

 rather presume it has functions distinct from 

 the stem, analogous, as has been hinted 

 p. 55, to digestion, at least in those plants 

 whose stems are annual though their roots 

 are perennial. 



The fibres of the root, particularly those 

 extremities of them which imbibe nourish- 

 ment from the earth, are in every case stnctly 

 annual. During the winter, or torpid season 

 of the year, the powers of roots lie dor^ 



