Floating Primrose-willow

Geographical Origin and Habitat: Native to temperate and tropical regions of North and South America. Commonly found along pond edges, slow rivers, and marshes, growing submerged, floating, or emersed.

Taxonomy & Genetics: Member of the Onagraceae family. Produces creeping, branched stems. When growing emersed, it produces bright yellow five-petaled flowers.

Physical Structure: Fleshy and highly branched stems that can reach substantial lengths. Submerged leaves are alternate and lanceolate, while emersed leaves are broader.

Color & Texture: Submerged foliage is bright green, occasionally developing golden tints under strong light. Texture is soft and smooth.

Lighting & CO2: Requires high light levels to prevent leggy and weak stems. CO2 injection is not mandatory but significantly accelerates growth rate.

Nutrition & Substrate: Thrives either rooted in a medium substrate or floating. Roots absorb massive amounts of nitrates and phosphates, helping control algae.

Water Chemistry: Extremely hardy and cold-tolerant (down to 15°C). Prefers pH 6.0-8.0 and adapts to a wide range of water hardness levels.

Space Management & Placement: Best suited for the background of large aquariums or as a floating cover. Due to its fast growth, it can easily overgrow other plants.

Pruning: Frequent trimming is necessary. Simply cut the stem tops and replant them into the substrate to propagate new stems.

Risks & Diseases: Shading of lower leaves due to insufficient light. Outside the hobby, it is classified as a highly invasive weed in many countries.