Ludwigia palustris is a species of flowering plant in the evening primrose family known by the common names marsh seedbox, Hampshire-purslane and water purslane. Its native distribution is unclear, but includes parts of the Americas; it can be found on most continents and spreads easily to become naturalized. It is also cultivated as an aquarium plant. This is an aquatic or semiaquatic perennial herb which grows in moist to wet to flooded areas. It is sometimes.