Welcome to the Osprey Outlook boardwalk. The Salt Marsh habitat is flooded by the high tide every day, twice a day. Smooth cord grass is the dominant plant in this environment. It is capable of secreting salt through its leaves, enabling it to survive in a harsh, salt water environments. Smooth Cord Grass stops growing at the edge of the Salt Marsh where you’ll see that it is replaced by Black Needle Rush. Black needle rush requires fresh water to survive, so it is confined to the edges of the salt marsh, where it is influenced by the fresh water runoff from higher ground.