236 



STRUCTURE AND VITAL PROCESSES OF PLANTS 



3. Twininf) Climbers. — The stems of these climbers wind 

 round their supports, some in the direction in which the hands of 

 a watch move (Yam), and others in the opposite direction (Bind- 

 weeds, Shankapushpa). If unwound and turned the other way, 



Fig. 214. — Tendril of Luff a acutangula' 



the young parts will insist on following 

 their original direction. 



4. Scramblers, e. ()., the Rose, the Wild 

 Asparagus, Lantana, Boiigaiiivillea, etc. 

 These climbers stretch their tips through 

 the holes of the thicket in which they grow, 

 and then open their branches wide so that 

 they may not glide down. Hooks and 

 spines are often made use of to the same 

 purpose. 



A common feature of these climbers is 

 their (juick growth and the absence of 

 leaves and branches at their tips, called 

 forerunning tips (see page 87). 



5. Strength of Stems. 



As the stem with its heavy load of leaves, flowers and fruits, 

 high up in the ;iir, is subjected to the bending, pulling and 



Fiff. 



2 15. — Twining stem of 

 Argijrcia speciosa. 



