Ranunculus inundatus

Ranunculus inundatus is native to eastern Australia, where it inhabits slow-moving and still freshwater pools, creek margins, and seasonally inundated floodplains. It belongs to the buttercup family and is one of the few Ranunculus species successfully cultivated as an aquarium plant. Its most distinctive feature is the finely lobed, umbrella-like submerged leaves held on elongated petioles, giving each plant a delicate, dancing quality as water movement causes the leaves to sway. In the aquarium it is used as a foreground or low-midground plant where this movement can be fully appreciated. It grows to about 15 cm in height, taller than most carpet plants, but its open, airy structure does not block light from lower-lying plants. Ranunculus inundatus prefers cooler water than most tropical aquarium plants, performing best below 24°C, which makes it ideal for subtropical, temperate, or unheated room-temperature setups. At warmer tropical temperatures its growth slows and leaves may deteriorate. It spreads gradually through the substrate via runners and occasional adventitious plantlets, building a loose but distinctive ground cover. In cooler tanks it pairs beautifully with Vallisneria, Java Fern, and coldwater mosses.

Placement Best placed in the foreground or low-midground of cool to subtropical aquariums. Space plants 5–7 cm apart and allow the petioles to develop their characteristic height. Avoid placing taller plants too close in front.

Lighting Moderate lighting (30–60 PAR) is generally sufficient. The plant does not require extremely high light and in fact prefers stable, moderate illumination without intense heat from high-wattage fixtures. A photoperiod of 8–10 hours works well.

CO2 & Fertilisation CO2 injection at low-to-moderate levels (10–20 ppm) helps growth. Root tabs or nutrient-rich substrate support the plant well. Avoid excessive phosphate, which can cause algae problems in the cooler, lower-light conditions this plant prefers.

Propagation The plant produces runners and occasional side plantlets at the base. These can be separated and replanted once they develop sufficient roots. Propagation is slow; expect 2–4 new plants per month under good conditions.

Trimming Remove damaged or yellowing outer leaves at the base regularly. Thin the developing colony by removing excess runner plantlets to prevent overcrowding. The open, flowing nature of the plant means trimming should be minimal to preserve the visual effect.