Ludwigia sphaerocarpa

Ludwigia sphaerocarpa is a specialist collector species from the eastern United States, rarely encountered in the aquarium hobby. It produces slender, linear to lance-shaped leaves with a warm pinkish-red flush under high light, and its species name refers to the distinctively rounded, spherical fruit capsules it forms in emersed conditions.

In aquarium culture it behaves as a demanding high-tech stem plant, requiring soft to moderately soft water, good lighting, and CO2 injection for healthy growth. It grows at a moderate pace and benefits from regular trimming to prevent lower leaf loss.

Primarily of interest to botanical collectors and rare-plant enthusiasts, L. sphaerocarpa adds variety to Ludwigia collections and pairs well with arcuata and brevipes for a fine-leaved, red-toned background grouping.

Light: High (60–90 PAR); pinkish-red tones develop only under strong illumination. CO2: Required at 20–30 mg/L; growth rate and colour both dependent on CO2 availability. Fertilisation: Iron and micronutrients weekly; avoid phosphate deficiency which causes leaf drop. Placement: Background; plant in groups of 5–7 with 2–3 cm spacing. Propagation: Trim tops at 12–15 cm and replant; roots develop within 5–7 days.