Bolboschoenus maritimus is a species of flowering plant from family Cyperaceae. Common names for this species include sea clubrush, cosmopolitan bulrush, alkali bulrush, saltmarsh bulrush, and bayonet grass. It is found in seaside wetland habitats over much of the world. It is widespread across much of temperate and subtropical Europe, Africa, Asia, North America, South America and various islands.