ORGANS OF NUTRITION. 



107 



tendrils ; or in Ivy, Avhere they emit little root-like processes 

 from their sides, by Avhich they adhere to neighbouring bodies 

 (Jig. 203). If such stems twist round other bodies in a spiral 



Fig. 204. 



Fig. 203. 



Fig. 205. 



Fig. 203. 

 Climbing stem of the Ivy 



Fig. 205. 

 Stem of Convolvulus. 



Fig. 204. Stem of Honeysuckle. 



manner they are said to he twining ; and this may take place 

 either from right to left, as in some Convolvuli (Jig. 205), in 

 the French Bean, and Dodder; or from left to right, as in the 

 Honeysuckle (Jig. 204), Hop, and Black Bryony; or first in one 

 direction and then in another, irregularly, as in the White 

 Biyony. These climbing and twining plants are generally 

 herbaceous or die annually when growing in cold and tempe- 

 rate regions, although we have exceptions to this in the Vine, 

 Clematis, and Honeysuckle which have woody stems ; in which 

 case such a stem has received the name of sarmentum. In 

 tropical climates these woody creeping or twining stems often 

 occur ; they are called lianas, and these ft-equently ascend to 

 the tops of the loftiest trees, and then either descend to the 

 ground again, or run to the branches of neighbouring trees. 



The stem has received many names according to its nature. 

 Thus it is called a caulis in plants which are herbaceous, or die 



