Ludwigia encompasses annuals, perennials, and subshrubs, most of them connected to water in some form — bogs, lake margins, slow streams, and ponds. The yellow flowers open in the evening and persist across a long bloom season, producing abundant seed that allows the genus to move quickly into new territory. Stems root at the nodes as they trail along the ground, and a single plant can extend nine feet or more.

This adaptability is the core of the genus story: the same qualities that make Ludwigia species useful in aquariums and water gardens have allowed escaped plants to naturalize aggressively in wild wetlands, where some species are classified as noxious weeds. Selecting species carefully for the intended setting, and managing spread deliberately, is the responsible way to work with this genus. In contained water features with careful attention, the summer evening flowers reward the effort.