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.
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.