Limnobium spongia Care Guide
American frogbit, a floating plant with spongy-undersided leaves that provides surface shade and nutrient uptake in soft, slow-moving water tanks.
Overview
Limnobium spongia, the American frogbit, is a floating plant in the family Hydrocharitaceae. It produces heart-shaped to nearly rounded floating or emersed leaves, roughly 2-7 cm in diameter, with a thick layer of spongy aerenchyma on the underside of floating leaves that aids buoyancy. It provides effective surface coverage and shade. Following taxonomic revision the species is also classified as Hydrocharis spongia.
Taxonomy
- Family: Hydrocharitaceae
- Genus: Limnobium (also treated as Hydrocharis following revision)
- Scientific name: Limnobium spongia
- Common name: American Frogbit
Habitat
The species is native to the central and southeastern United States, ranging across states from Texas and Florida north to New York and Connecticut. It thrives in slow-moving or stagnant water with muddy substrate, including sloughs, ditches and swampy forests. Its whitish root systems hang in the water column and can host zooplankton.
Tank requirements
- Light: medium
- CO2: not required
- Temperature: 18-28 °C (64-82 °F)
- pH: 5.5-7.5
- GH: 2-14 °dGH
- Placement: floating
- Growth rate: fast
Care and growth
As a fast-growing floating plant it shades the water below, which can suit blackwater and biotope setups, and it draws nutrients from the water. Keep humidity above the tank moderate, since condensation or droplets sitting on the leaves of floating plants can cause melt. Thin the mat periodically so light still reaches plants beneath.
Propagation
The plant spreads readily by runners (stolons) and division. New rosettes form on runners and can be separated once they have their own roots and leaves.