Barclaya longifolia

Barclaya longifolia is a member of the water lily family (Nymphaeaceae) and is often described as one of the most dramatically beautiful aquarium plants available when it reaches its full potential. Native to Myanmar, Thailand, and nearby regions of Southeast Asia, it produces long, lance-shaped leaves with strongly undulating margins and a rich coloration that ranges from olive-green to deep burgundy-red depending on light intensity and genetics of the individual specimen. The leaves emerge from a rhizome and can reach 30–40 cm in length, with the wavy margins creating a flowing, frilled appearance reminiscent of an underwater ballroom gown. Unlike many aquarium plants, Barclaya longifolia requires a consistently warm environment (24–30°C) and is intolerant of temperature fluctuation. It also requires soft, acidic to slightly acidic water, making it unsuitable for hard-water or cichlid tanks. CO2 supplementation and nutrient-rich substrate are both important for achieving the robust growth and deep red coloration that make this species so prized. The plant does not produce runners but instead grows larger from its existing rhizome, occasionally producing offsets that can be carefully separated for propagation. Despite its beauty, Barclaya longifolia is classified as advanced due to its sensitivity to parameter instability and the precision of care it demands. Under ideal conditions it is an extraordinarily rewarding centerpiece species.

Planting Plant the rhizome half-buried in fine, nutrient-rich substrate. Never fully bury. Use aqua soil or place root tabs 3–4 cm beneath. Allow adequate space — mature plants span 30–40 cm in diameter.

Temperature Stability Barclaya longifolia is one of the most temperature-sensitive common aquarium plants. Maintain 24–30°C with minimal fluctuation. A reliable heater and thermometer are essential.

Lighting Moderate to moderately strong light (35–60 µmol/m²/s PAR) develops the best red coloration. Low light causes greener leaves; strong light with inadequate nutrients causes bleaching.

CO2 and Fertilization CO2 injection at 25–35 ppm is highly recommended. Root tabs replaced every 2–3 months are essential. Weekly liquid fertilizer with iron supports the deep red pigmentation.

Water Conditions Requires pH 5.5–7.0, temperature 24–30°C. Soft water (GH 1–8) is strongly preferred. Hard, alkaline water causes progressive deterioration.

Dormancy May experience a brief rest period. During this time, reduce water changes and maintain stable temperature. New growth will resume from the rhizome.

Propagation Separate offsets from the main rhizome carefully, ensuring each has several roots and leaves.

Common Issues Temperature drops below 22°C cause rapid leaf deterioration. Hard water slowly kills the plant over weeks. Yellowing indicates deficiency — add chelated iron and micronutrients urgently.