Ludwigia helminthorrhiza

Ludwigia helminthorrhiza is unlike any other Ludwigia in cultivation. Native to South America, it grows primarily as a floating or surface-anchored plant, developing a dense cluster of bright green, rounded leaves on the surface while producing conspicuous feathery white aerial roots that hang into the water column below. These roots are not only functional but highly ornamental.

When anchored in substrate or weighted near the surface it can be encouraged to grow in an upright stem habit, though it naturally prefers to float. It benefits from strong lighting at the water surface and CO2, but the aerial roots mean it has access to atmospheric CO2, making it somewhat more tolerant than fully submerged stems.

A rare and unusual specimen plant best suited to large open tanks where it can float freely or be anchored in the background as a surface-area accent.

Light: High (60–100 PAR at surface); strongest growth when leaves receive direct illumination. CO2: Required or beneficial at 20–30 mg/L; aerial roots access atmospheric CO2 as supplement. Fertilisation: Liquid fertiliser into water column weekly; plant absorbs nutrients through roots. Placement: Surface-floating or anchored background; leave 10–15 cm of open water above. Propagation: Separate side rosettes that develop at nodes; each can grow independently.