124 



ORGANOGRAPHY. 



^ 



Fig. 239. irregularly towards the ends, as in the 



common Dropwort {Spireea Filipendula), 

 the root is nodulose (fig. 238) : when the 

 branches have alternate contractions and 

 expansions, so as to present a beaded 

 appearance, as in Pelargonium triste, the 

 root is moniliform, necklace- shaped, or 

 beaded {fig. 239) ; and when the root has 

 a number of ring-like expansions on its 

 surface, as in Ipecacuanha {Cephaelis 

 Ipecacuanha), it is annulated {fig. 240). 



The above forms of roots, with few ex- 

 ceptions, are those which are commonly- 

 observed in plants which have no true 

 tap-root. Those which have now to be 

 described owe their peculiar forms to modi- 

 Fig. 239. Moniliform root, fi.^tions of this latter kind of root. 



Conical Root. — When a tap-root is broad at its base, and tapers 



Fig. 240. 



Fig. 241. 



Fig. 240. Annulated root of Ipecacuanha (Cephaelis Ipecacuanha). 

 Fig. 241. Conical root of the conamon Carrot. 



