Frogbit Smut (Tracya hydrocharidis)
Key Details
| Taxonomic Groups: | Fungus or lichen > fungus > Fungus |
| Red List Status: | (Not Relevant) [(not listed)(nr)] |
| D5 Status: | |
| Section 41 Status: | (not listed) |
| Taxa Included Synonym: | (none) |
| UKSI Recommended Name: | Tracya hydrocharidis |
| UKSI Recommended Authority: | Lagerh. |
| UKSI Recommended Qualifier: | (none specified) |
| Red List Citation: | (not listed) |
| Notes on taxonomy/listing: | (none) |
Criteria
| Question 1: | Does species need conservation or recovery in England? |
| Response: | Yes |
| Justification: | Assessed as Critically Endangered (2006) - non-historical records are restricted to the SW,SE and E.Anglia |
| Question 2: | Does recovery/ conservation depend on species-specific actions? |
| Response: | Yes |
| Justification: | It is reliant on the success/distribution of a specific plant species, (Hydrocharis morsus-ranae) Which as part of the TSRA project should see an eventual increase in population growth/distribution. However without evidence of the current national status of this species it will be very difficult to monitor this |
| 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: | No |
| Justification: | There is no evidence that an increase in the structural diversity of the habitat will directly benefit this species. |
Species Assessment
| Current step on the Species Recovery Curve (SRC): | 2. Biological status assessment exists |
| Recovery potential/expectation: | Medium-high |
| National Monitoring Resource: | Opportunistic - insufficient |
| Species Comments: | This is a smut fungus that exists only on Hydrocharis morsus-ranae. A reversal of the host plant's habitat decline could be beneficial to the host and therefore to this species. All other comments and actions should be taken from the responses given for Hydrocharis morsus-ranae which is also part of the TSRA project. |
Key Actions
Key Action 1
Proposed Action: An assessment of the necessary national species records should be made according to IUCN guidelines to provide a recognised redlist status criteria for this species.
Action targets: 2. Biological status assessment exists
Action type: Status survey/review
Duration: 1 year
Scale of Implementation: National
High priority sites: N/A
Comments: As no IUCN recognised assessment exists for this species, this action should be prioritised.
Key Action 2
Proposed Action: For this fungus to recover, existing populations of its host plant need to be managed correctly and expanded. The host is a TSRA species, so that will be covered by actions given for that species. Once that is complete, a pilot study on translocating the rust fungus into other populations should be undertaken.
Action targets: 6. Recovery solutions trialled
Action type: (Re-)introduction
Duration: 3-5 years
Scale of Implementation: ≤ 20 sites
High priority sites: N/A
Comments: See Hydrocharis morsus-ranae TSR actions for details on host plant recovery. Trials on assisting the recovery/distribution of this smut fungus may benefit from ex-situ propagation of infected host plants.
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.