Probably Halophytes, as they are able to metabolise salt or brack water and are normally found in arid and harsh environments.
what are the possible plants that grow in lowland areas
Cocoa plants grow best in areas where the lands are able to drain the water a little easier. Thus, really damp areas would not be a good place for them to grow.The Eastern Andean Mountains are however.
nothing...
No plants specifically grows in beach soil.
xerophytes
High tides and heavy surf make it very difficult for plants to take roots in the sand along the lower beach.
Dandilions.
Because mosses require water for their motile gametes and also being very delicate damp areas are best for growth
Most plants won't grow in soil has salt in it. Some plants will still grow, there are often the types of plants you see growing near the beach.
Damp shady
Bryophytes and ferns grow in damp or wet areas and out of strong sunlight
Cotton grows best in semi-sandy soil. It will grow best near the beach.