Atolls occur in almost all of the ocean basins around the world. As far as the distribution of flora ON an atoll, most plants are widely distributed and opportunistic. Endemism is low because they are located (usually) far from larger land masses that could easily populate them. Also, most atolls are not that old, so the flora has not had as much time to evolve as on other larger, older land masses. Most plants are thought to come to islands via birds.
