Ludwigia repens is a species of flowering plant in the evening primrose family[1] known by the common name creeping primrose-willow.

It is native to parts of the Americas and it has the potential to spread easily and become naturalized in many areas.

This is a mat-forming perennial herb with a creeping stem up to 30 centimeters long, rooting at nodes which come in contact with wet substrate.

The flower has four yellow colored petals no more than 3 millimeters long nested on a base of four pointed sepals which may be slightly longer.

A recent study found that the phytochemicals present in L. repens act as a potent central nervous system depressant and painkiller in vivo.