The red color giving red ludwigia its common name is not always obvious. It and its close relatives are known generally as waterprimrose or waterpurslane. Red ludwigia will grow upright initially but soon becomes prostrate and will root at the lower nodes.

The leaves of red ludwigia are opposite in two planes. Red lugwigia is also known as waterprimrose and waterpurslane. There are several closely related species. Many were once in the genus Jussiaea or Isnardia.