THE VERBENA FAMILY 



355 



THE ROOTS OF THE MANGROVE. 



A tree which grows in salt water must, of necessity have roots 

 differing much from those of a tree growing on land, and the 

 root structure of Avicennia, as of all mangroves, is replete 



Fig. 116. Mangrove trees, showing aerial roots. 



with points of interest. Botanically speaking, the root is the 

 result of the development of the rootlet of the embryo, and it 

 would seem an easy matter, therefore, to distinguish between 

 root and stem. In many cases it is so, but there are some 

 plants in which the root simulates a stem (v. Metrosiderox 



