Ludwigia peruensis

Ludwigia peruensis is a South American aquatic stem plant native to Peru and surrounding regions of the western Amazon Basin, where it grows in shallow waterways, marshes, floodplain edges, and slow-moving streams. In nature it is often found in areas that experience seasonal fluctuations in water level, allowing it to grow both submerged and emersed depending on conditions. These habitats typically feature nutrient-rich substrates, warm temperatures, and moderate to strong light exposure.

Under submerged aquarium conditions, Ludwigia peruensis develops long, lance-shaped leaves that range from olive green to deep red depending on lighting intensity and nutrient availability. With strong light and stable nutrients, the upper growth often transitions to vivid red, burgundy, or crimson tones, while lower portions remain darker green to bronze. Stems are sturdy and upright, and the plant grows vertically toward the surface before branching. When grown emersed, leaves become slightly thicker and can show more pronounced coloration.

Ludwigia peruensis is best suited for medium to large aquariums where vertical growth can be appreciated. It is typically planted in groups to create a dense, colorful background or midground feature. Moderate to high lighting is strongly recommended to bring out red coloration and compact growth. Without sufficient light, the plant tends to remain green and may grow leggy with wider spacing between leaves.

Water conditions are flexible but should be stable. Temperatures between 72 and 82 degrees Fahrenheit are appropriate, with a pH range of roughly 6.0 to 7.5. Soft to moderately hard water is suitable. While the plant can survive without CO₂ injection, supplemental CO₂ significantly improves growth rate, leaf density, and red pigmentation.

Ludwigia peruensis is primarily a water column feeder but also benefits from nutrient-rich substrate. Regular fertilization with nitrogen, phosphorus, potassium, and trace elements supports healthy growth and strong coloration. Iron supplementation may enhance red tones when other nutrients are balanced. Pruning is straightforward and necessary to maintain shape; trimmed tops can be replanted to propagate the plant.

This species is compatible with most community fish and invertebrates. Its firm leaves are generally resistant to mild grazing, though large herbivorous fish may damage new growth. Dense plantings provide cover for fish and fry and add depth and color contrast to planted aquascapes.

Ludwigia peruensis is a bold, fast-growing red stem plant that brings vertical structure and vibrant coloration to freshwater aquariums. With adequate light and nutrients, it develops rich red hues and strong growth, making it an excellent choice for planted tanks seeking dramatic contrast and height.