Hydrocharis dubia

Hydrocharis dubia is native to Asia, distributed from India and Sri Lanka through Southeast Asia to Japan and Australia. Its floating leaves are slightly larger, rounder, and more glossy than those of the European H. morsus-ranae, and it produces particularly dense, feathery hanging root systems that shrimp graze on enthusiastically and that provide excellent shelter for fry. It thrives in warmer water than its European relative, making it better suited to tropical community tanks. Growth is vigorous under bright surface light and it spreads via stolons rapidly, requiring periodic thinning to prevent surface overcrowding. It adapts to both still and lightly flowing water.

Light: Medium to high (40–80 PAR at the surface); floating habit provides direct light access. CO2: Not required; absorbs CO2 directly from the air above the water surface. Fertilisation: Light liquid fertiliser every 1–2 weeks absorbed through the hanging roots. Placement: Floating surface cover in tropical tanks; thin weekly to maintain 50–70% surface coverage. Propagation: Stolons with daughter plantlets produced continuously; remove excess to control spread.