96 



ELEMENTS OP STRUCTURAL BOTANY. 



Fig. 124. 



Bean, or it may branch at an early stage into numerous 

 similar threads, and so form a fibrous root, as in Buttercup. 



133. Tap-roots receive different names according to 



the particular shape they happen to assume. 

 Thus, the Carrot (Fig. 124) is conical, because 

 from a broad top it tapers gradually and regularly 

 to a point. The Radish, being somewhat thicker 

 at the middle than at either end, is spindle- 

 shaped. The Turnip, and roots of similar shape, 

 are napiform (napus, a turnip). 



These fleshy tap-roots belong, as a rule, to 

 biennial plants, and are designed as storehouses 

 of food for the plant's use during its second year's 



growth. Occasionally fibrous roots also thicken in the 



same manner, as in the Peony, and then they are said to 



be fascicled or clustered. 



(Fig. 125). 



134. But you must have 

 observed that plants some- 

 times put forth roots in 

 addition to those develop- 

 ed from the embryo of the 

 seed. The Verbena of our 

 gardens, for example, will 

 take root at every joint if 



the stem be laid upon the ground (Fig. 126). The 

 runners of the Strawberry take root at their extremities; 

 and nothing is more familiar than that cuttings from 

 various plants will make roots for themselves if put into 

 proper soil, and supplied with warmth and moisture. 



Fig. 124. Tap-root of Carrot. 



Fig, 125. Fascicled roots of Peony. 



