Bladder-Seed Rust (Puccinia physospermi)
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: | Puccinia physospermi |
| UKSI Recommended Authority: | Pass. |
| 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) also, it's recovery is dependent on the success of a plant that declined over 50% after the 1970s. It is restricted to its native range in South Devon, and there is a separate population in Buckinghamshire. |
| Question 2: | Does recovery/ conservation depend on species-specific actions? |
| Response: | Yes |
| Justification: | Without evidence of the current national status of this species it will be very difficult to assess if there are any other species-specific actions required for its conservation; or if it is need of conservation at all. |
| 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: | Habitat disturbance increases the host plant's resilience against competition for space and light. So increasing structural diversity should benefit the host and therefore this rust fungus 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 rust fungus. It's recovery/conservation is reliant on the success/distribution of a specific plant species, ( Physospermum cornubiense). This plant is not 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: Cornwall, South Devon & Burnham Beeches
Comments: For a rust species on a rare host plant, the BSBO plant atlas will provide a useful list of available 'habitat' sites. As no IUCN recognised assessment exists for this species, this action should be prioritised.
Key Action 2
Proposed Action: Collect seed of host plant and cultivate ex situ with the rust for introduction to suitable host sites.
Action targets: 6. Recovery solutions trialled
Action type: Ex situ conservation
Duration: 3-5 years
Scale of Implementation: ≤ 20 sites
High priority sites: South Devon & Burnham Beeches
Comments: Host plant species should undergo some combination of protection/redlisting/translocation to improve host plant availability.
Key Action 3
Proposed Action: Habitat management for the plant to include bracken management. Bracken is potentially outcompeting the bladder-seed which is the host of the rust.
Action targets: 7. Best approach adopted at appropriate scales
Action type: Habitat management
Duration: 3-5 years
Scale of Implementation: ≤ 20 sites
High priority sites:
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.