Frogbit (Hydrocharis morsus-ranae)
Key Details
| Taxonomic Groups: | Vascular plant > flowering plant > Aquatic plant |
| Red List Status: | Vulnerable (Not Relevant) [VU(nr)] |
| D5 Status: | Included in the baseline Red List Index for England (Wilkins, Wilson & Brown, 2022) |
| Section 41 Status: | (not listed) |
| Taxa Included Synonym: | (none) |
| UKSI Recommended Name: | Hydrocharis morsus-ranae |
| UKSI Recommended Authority: | L. |
| UKSI Recommended Qualifier: | (none specified) |
| Red List Citation: | in Stroh et al., 2014 |
| Notes on taxonomy/listing: | (none) |
Criteria
| Question 1: | Does species need conservation or recovery in England? |
| Response: | Yes |
| Justification: | A floating aquatic herb that, as a native, mainly occurs in species-rich ditches in grazing marshes in low-lying wetland areas of England (e.g. Somerset Levels, Fenland, Norfolk Broads, Cheshire Plain, etc.). It spreads by vegetative fragments and thus is able to colonise new sites. Elsewhere it is an occasional escape from ornamental planning in ponds and lakes. It has suffered historic declines due to the loss and modification of wetlands and as a consequence it was categorised as VU in GB and England (Cheffings et al., 2005; Stroh et al., 2014). However, the results of Plant Atlas 2020 showed that it is relatively stable in its core range and may even by increasing in some areas (Stroh et al., 2023). |
| Question 2: | Does recovery/ conservation depend on species-specific actions? |
| Response: | Yes |
| Justification: | Within its key areas it current conservation measures a probably adequate but there is potential for recovery in areas where it formerly occurred (e.g. Yorkshire, Lincolnshire, Midlands) through habitat creation and reintroduction schemes. |
| Question 3: | At a landscape scale, would the species benefit from untargeted habitat management to increase habitat mosaics, structural diversity, or particular successional stages? |
| Response: | Yes |
| Justification: | Within its core areas this species is likely to colonise newly created sites as part of large-scale landscape recovery schemes (e.g. Great Fen in Cambridgeshire). |
Species Assessment
| Current step on the Species Recovery Curve (SRC): | 4. Autecology and pressures understood |
| Recovery potential/expectation: | Medium-high |
| National Monitoring Resource: | Opportunistic - sufficient |
| Species Comments: |
Key Actions
Key Action 1
Proposed Action: Undertake an assessment of historic sites that are suitable for reintroduction.
Action targets: 5. Remedial action identified
Action type: Status survey/review
Duration: 2 years
Scale of Implementation: ≤ 10 sites
High priority sites: To be determined
Comments:
Key Action 2
Proposed Action: Ex situ cultivation of material for reintroduction to sites identified in the site survey/review.
Action targets: 6. Recovery solutions trialled
Action type: (Re-)introduction
Duration: 3-5 years
Scale of Implementation: ≤ 10 sites
High priority sites: To be determined
Comments:
Acknowledgment:
Data used on this website are adapted from Threatened species recovery actions 2025 baseline (JP065): Technical report and spreadsheet user guide (Natural England, 2025). Available here.