Green Ludwigia (Repens) is one of the easiest plants to grow in an aquarium. Able to grow in even lower light conditions (down to 1.75 watts per gallon with power compacts). It also makes an excellent candidate for moderately lit, non-CO2 aquaria. When lit well, the plant will grow at an angle over the substrate instead of straight up.
This plant does well in nano tanks and is especially suited to the bioAquatiX bioBowl micro eco-systems.
It's a mat-forming perennial herb with a creeping stem up to 12 inches long, rooting at nodes which come in contact with wet substrate. The leaves are oppositely arranged and up to 4 or 5 centimeters long. 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.