VEGETATIONAL TYPES OF TROPICAL LANDS 



435 



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leaves of tough consistency. They often have interesting structural 

 modifications which appear to assist their adherence to the sub- 

 stratum, though normally they do not have any appreciable ill-effect 

 on leaves even when they largely cover their surfaces. 



5. Str anglers. These are plants which begin life as epiphytes but 

 later send down roots to the soil, becoming independent or nearly 

 so, and often killing the tree which originally supported them. 



Fig. 148. — -Roots of Strangling Fig on a large tree-trunk. 



They thus form a synusia which is biologically intermediate between 

 dependent and independent plants. Most familiar and plentiful in 

 both species and individuals are, widely, the Strangling Figs {Ficus 

 spp.), which may play a considerable part in the economy as well as 

 physiognomy of the rain forest. The seeds commonly germinate 

 far up in the forks of tall trees and from the epiphytic bush first 

 formed are developed long roots which descend to the ground, those 

 nearest the trunk of the supporting tree branching and anastomosing 

 until it is encased in a strong network (Fig. 148). After a time 

 the original tree usually dies and rots away, leaving the strangler. 



