Pia eROOT 201 
These roots grow out in whorls from the lower nodes and serve 
to brace the stem of the plant. 
Prop roots are conspicuous in many species of the genus 
Ficus (Fig. 198), and particularly in the banyan tree. In the 
latter case large roots extend down from the larger branches 
and serve as secondary 
trunks. As aresult one 
plant may extend over 
a considerable area and 
be supported by a large 
number of prop roots 
which, from the stand- 
point of function, may 
be regarded as addi- 
tional trunks. 
Another very inter- 
esting example of sup- 
porting roots is afforded 
by the strangling figs of 
tropical forests. ‘These 
plants start as epiphytes 
in the tops of the trees 
and send down roots 
that reach the ground 
(Fig. 199). Branches 
from these roots grow 
around the tree and coa- . Fra. 199. Roots of strangling fig on a 
lesce, either with each large tree trunk 
other or with the main 
root, until the trunk of the tree is usually inclosed by a network. © 
As this grows and coalesces, it interferes with the growth of the 
tree, the fig leaves shade the tree, and the roots of the fig inter- 
fere with those of the tree. This combination usually results in 
the death of the tree on which the fig is growing. The mesh- 
like support of the fig continues to grow until it may finally 
have the appearance of a solid trunk. Usually, however, some 

