Hydrocharis morsus-ranae Care Guide
European frogbit, a cool-tolerant floating plant with kidney-shaped leaves and small white flowers that spreads by runners on still water.
Compiled by Aquairi from published sources · Published · Updated
Overview
Hydrocharis morsus-ranae, the European or common frogbit, is a free-floating perennial in the family Hydrocharitaceae. It forms rosettes of circular, kidney- to heart-shaped floating leaves with visible aerenchyma on the underside, and unbranched white roots that can extend well into the water column. It produces small white flowers with three petals and is dioecious.
Taxonomy
- Family: Hydrocharitaceae
- Genus: Hydrocharis
- Scientific name: Hydrocharis morsus-ranae
- Common name: European Frogbit, Common Frogbit
Habitat
The species is native to Europe and Asia, where it grows in slow-flowing rivers, stagnant waters, aquatic ditches and oxbow lakes. It can form dense masses of vegetation on the surface. It was introduced to North America in 1932 and is now invasive in eastern Canada and several northern U.S. states, where trade is restricted in some areas.
Tank requirements
- Light: medium
- CO2: not required
- Temperature: 15-26 °C (59-79 °F)
- pH: 6.0-8.0
- GH: 4-18 °dGH
- Placement: floating
- Growth rate: medium
Care and growth
European frogbit tolerates cooler temperate conditions better than many tropical floaters, which makes it suited to unheated or coldwater setups, though it adapts to warmer water as well. It accumulates nutrients and even heavy metals from the water and provides surface shade. Thin the surface mat so light reaches plants beneath.
Propagation
It spreads by stolons (runners), forming new daughter rosettes that separate from the parent. In temperate climates it overwinters as turions, dormant buds that sink and resprout in spring.
Propagating Hydrocharis morsus-ranae (European Frogbit) by Stolons
Overview
Hydrocharis morsus-ranae, European frogbit, is a free-floating flowering plant with circular floating leaves that have visible aerenchyma underneath and petioles 6-14 cm long. It grows as individual rosettes that the plant links together, ranging from 1 to 30 cm. Its small flowers carry three greenish-red sepals and white petals.
It is native to Europe and Asia, where it lives in slow-flowing rivers, stagnant waters, ditches and oxbow lakes, so it favours calm, still surfaces in the aquarium.
Propagation Method: Offsets on Stolons
European frogbit reproduces through stoloniferous growth, developing individual rosettes connected along the stolons. New daughter rosettes form along these runners, so the plant multiplies vegetatively into a connected colony. Propagation is simply separating the established daughter rosettes.
Step-by-Step
- Let the parent rosette grow until it pushes out stolons bearing small daughter rosettes.
- Wait until each daughter rosette has formed its own floating leaves.
- Gently separate the daughter rosette from the connecting stolon.
- Return the separated rosette to a calm patch of the surface so it can re-establish.
- Lift connected colonies out in one piece when thinning.
Conditions for Healthy Growth
- Placement: free-floating on a calm, still surface.
- Temperature: 15-26 C; tolerant of cool to subtropical water.
- pH 6.0-8.0, GH 4-18.
- Lighting: medium light.
- Avoid strong surface movement that wets the floating leaves.
Maintenance
Thin the colony regularly so it does not cover the whole surface and shade out plants below. Because connected rosettes form dense surface masses, scooping out clumps every couple of weeks keeps growth in check.
Common Challenges
The dominant challenge is its vigour: it readily forms dense masses on the surface. Controlling spread inside the tank and, above all, preventing any escape into the wild are the key concerns for this species.