This is a kind of Mucuna seed, often called a Sea Bean or Hamburger Bean. It is the seed of a tropical vine from Central and South America. Other species of Mucuna are found in tropics around the world. Their seeds float, and are very strong. They are carried down rivers to the ocean, and then move with the currents. They are often found on beaches thousands of miles from where they originated. We have collected several different species from around the world on the beach in St. Augustine.