Question

What are PNEUMATOPHORES ??

Answer 1

the gas-filled float of some colonial coelenterates, such as the Portuguese man-of-war.
or
(in mangroves and other swamp plants) an aerial root specialized for gaseous exchange

Answer 2

Pneumatophores are modified roots. They are aerial roots which are meant for exchange of gases. The mangroves trees growing on marshes have such kind of roots as adaptive feature.