ROOTS ABOVE GROUND 11 



and poison ivy climb by means of roots. The roots often 

 remain on the wall or other support after the plant is torn off. 

 32. In some plants, all the roots are aerial; that is, the 

 plant grows above ground, and the roots absorb water from 

 the air and from the bark of the tree on which they grow. 

 Such plants are known as epiphytes or air-plants (Chapter 

 XV). The most familiar examples are some of the tropical 

 orchids, which are grown in glasshouses. (Fig. 13.) 



33. Some plants throw out aerial roots that propagate 

 the plant or act as braces. The roots of Indian corn are 



15. A banyan tree in India. The old trunk is seen (at the left), together with 

 many trunks formed from the aerial roots. 



familiar. (Fig. 14.) Many licus trees, as the banyan of India 

 (Fig. 15), send out roots from their branches; when these 

 roots reach the ground they take hold and become great 

 trunks, thus spreading the top of the parent tree over large 



