Mangroves extract salt from water via transpiration and filtering through membranes.


“Nature did not refrain from using energy produced in the power stations of plants for other important functions of life. One example is the desalination of seawater by evaporation energy. At the edge of shallow coastal waters of tropical seas we find the luscious green of mangrove swamps. Mangroves can live on the saline water of the ocean, which destroys other green terrestrial plants. In some species of mangroves the sap is almost salt-free, though the roots are washed by sea water. They extract the salt by using the transpiration energy in the narrow capillaries of their roots to suck up the sea water and then filtering it through thin membranes in which the salt is detained.” (Tributsch 1984:184)

How Life Learned to Live: Adaptation in NatureJanuary 1, 1983
Helmut Tributsch