Cylindricfruit Primrose-Willow

Description

Ludwigia glandulosa, a species of primrose willow, has two subspecies: ssp. glandulosa and ssp. brachycarpa. It is found in the southeastern United States, extending to Illinois and Indiana in the north. The plant grows in wetlands and ditches, but is considered endangered or critically endangered in some areas. In aquarium trade, it is often mislabeled as "Ludwigia perennis", which is actually a different species from Asia, Africa, and Australia. It has lanceolate leaves that grow upright and rarely branch out. The plant produces inconspicuous green flowers in the summer. To culture Ludwigia glandulosa, it requires intense light, sufficient iron, and micronutrients. The plant sheds its lower leaves even with strong light. It grows well with moderate nitrate (5-25 mg/l) and phosphate (0.1-3 mg/l) levels. The submersed form of L. glandulosa does not branch out much and grows straight to the water surface. To induce lateral shoots, the central shoot needs to be cut off. The plant's intense reddish-purple color makes it an ideal accent plant for aquaria. Its slow growth rate and upright habit make it suitable for "plant roads" in Dutch tanks.