LECT. IV.] THE ROOT. TUBERS. 153 



because, although a new plant actually rises every 

 year from the new tuber, or that one in the regu r 

 lar order of succession ; yet each is only a conti- 

 nuation of the plant raised from the seed perpe- 

 tuated by lateral production, as the buds on an 

 ungrafted tree are continuations of the original 

 tree ; and differ essentially from the seedling 

 plant, which is a real renewal of the species. 



b. FJLIPENDULOUS TUBERS are attached to the 

 parent plant by underground runners, or cords, 

 which spring not from the roots but the lower part 

 of "the stem ; the roots being in this instance, as 

 in the plants with closely attached tubers, truly 

 v. fibrous. There are two 



species only of the fill- 

 pen dulo us tubers ; soli- 

 tary and congregated. 



I- The 5otorpen- 

 dulous tuber (Tuber so- 

 lit arium) (fig. v ) is egg- 

 shaped and attached, as 



by Sir J. E. Smith : " They are best removed when in full flower, 

 " the earth being cleared completely away from the roots 

 " (tubers), which are then to be replanted in their natural 

 " soil previously dried and sifted. Afterwards they must be 

 " well watered. The bulb (tuber) for the following year has 

 " not at the flowering period begun to throw out its fibres, for 

 " after that happens it will not bear removal." Introd. to phy- 

 siological and systematic Botany t p. 110. 



