$\rightarrow$ Pneumatophores : The plant group developing in swampy and humid areas of salt water at seashore is called Mangrove.

$\rightarrow$ Many roots of these plants develop towards opposite direction of gravity and longitudinally from soil directly.

$\rightarrow$ Such root are porous and unbranched. It helps to get oxygen for respiration. They are called Pneumatophores or respiratory root.