THE STEM 



235 



:12.— Tendrils at the leaf-tip 

 of Gloriosa superba. 



procumbent or prostrate (Evolvulus alsinoides). Creeping stems 



also lie prostrate on the ground, but form roots from their nodes 



(Ipomoea bijoha). 



Otlier weak stems assume the habit of climbing other plants 



in the shade of which 



they grow, and thus 



raise their foliage to 



the life-giving liglit. 



From the various 



methods by which 



they climb, they can 



be classified as 



follows: — 



1 . Root-climbers, 



e. g.y the Pepper vine; 



these produce little 



clinging roots on the lower side of their stems, i. e., on that 



turned away from the light, to attach themselves to the support- 

 ing t r u n k f a 

 tree or to a wall. 

 2. Tendril- 

 climbers, e.g., the 

 Pea, the Cucum- 

 ber, the Gloriosa. 

 These a 1 1 a c h 

 themselves to 

 their supports by 

 means of tendrils, 

 which are some- 

 times merely the 

 tapering ends of 

 the mid-rib (Pea, 

 Gloriosa), some- 

 times the leaf- 

 stalks (Potato creeper and fig. 213), sometimes branches (Grape 



vine; Hippocratea Grahamii; Kan. Padiri), and sometimes 



separate organs growing from the axils of the leaves (Cucumber). 



Fig-. 2 IS.— Lophospermum 



scandens. The leaf-stalk 



used as tendril. 



