Sea Purslane forms an important and primary function in dune creation. Salt tolerant, it sets roots just above the high tide line. Sand-carrying wind hits the plant, slows slightly and drops the sand it is carrying. That helps build the dune and in time bring in other plants. It is an important part of beach re-newal.
It is edible. Sea Purslane was widely used by Native Americans. The stems were eaten raw or pickled, or cooked in two or more changes of water to reduce its saltiness. I find them a visual fractal delight. These growing on the quieter bay side of St. George Island, Florida last January.