128 



OKGAKOGKAPHY. 



dant at the base of their caudex, that they sometimes doul)le or 

 triple its thickness {fig. 1 59, n/), and hence give to the lower part 

 of such stems a conical form. Their internal structure in all 

 essential characters resembles that of the stem. 



We have now, in conclusion with roots, to describe some of 

 the more important forms which they present. 



Forms of Roots. — When a root divides at once into a number 

 of slender branches or rootlets, or if tlie primary root is but 

 little enlarged, and gives off from its sides a multitude of simi- 

 lar branches, it is csHqOl fibrous. Such roots occur commonly 

 in annual plants, and may be well seen in annual Grasses {fiy. 

 240), in bulbous plants {{figs. 224 and 225),&c. 



Fig. 240. 



Fig. 241, 



F!g. 240. Fibrous root of a Grass. 



Fig. 2-tl. Coralline root from 

 Corallorrhiza innata. 



Coralline Boot. — This name is applied to a root which 

 consists of a number of succulent branches of nearly equal size, 



Fig. 243. 



Fig. 242. 



Fig. 242. Tubercular roots of an Orchis. Fi>j. 243. Palmated tubercules of 



an Orchis. 



