Ludwigia peruviana, with the common names Peruvian primrose-willow or Peruvian water primrose, is an aquatic, sometimes deciduous species of flowering plant in the evening primrose family. It can grow to approximately 12 feet (3.7 m) in height. While native to Peru, it has been introduced in many other countries for its attractive simple yellow flowers, it is now a common weed in swampy areas around the world.