Ludwigia octovalvis, commonly known as Mexican primrose-willow, is a perennial herb that is native to a wide range of wetland habitats including marshes, pond margins, and slow-moving streams. Its distribution includes Central America, Southeast Asia, India, the Middle East, and Central-West Africa, but it is not native to Australia. Typically, it grows over a meter tall and can spread to form dense mats on mud or float in water, rooting at nodes. The plant features yellow flowers that bloom in the summer and are moderately showy, adding a splash of color to aquatic environments.

Mexican primrose-willow is valued for its rapid growth and ability to colonize wet areas, making it useful for erosion control and habitat restoration in its native range. However, its aggressive growth habit can be problematic, as it can outcompete native vegetation and alter wetland ecosystems. In cultivation, it requires consistently moist or wet soil conditions and can thrive in full sun to part shade. It is often used in water gardens and for naturalizing in wet areas. Gardeners should be cautious, as Ludwigia octovalvis is potentially invasive outside its native range and can be difficult to control once established.CC BY-SA 4.0