Triangular Club-rush (Schoenoplectus triqueter)
Key Details
| Taxonomic Groups: | Vascular plant > flowering plant > Sedge |
| Red List Status: | Critically Endangered (Not Relevant) [CR(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: | Schoenoplectus triqueter |
| UKSI Recommended Authority: | (L.) Palla |
| 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: | Species now extinct in the wild as a naturally-occurring plant, though introduced populations still survive on River Tamar (Devon/Cornwall) |
| Question 2: | Does recovery/ conservation depend on species-specific actions? |
| Response: | Yes |
| Justification: | As an species last seen as a naturally-occurring wild plant in England in 2010, the species is in urgent need of targeted conservation action. |
| 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: | The species has been lost through river engineering works, & vegetation succession (particularly lost to the spread of Common Reed Phragmites australis). The species appears poor at colonising new bare mud caused through natural erosion. General brackish marsh management (including managed realignment & removal of unnecessary sea defences) would improve habitat suitability for this & other species (which could reappear from buried seed or future colonisation). |
Species Assessment
| Current step on the Species Recovery Curve (SRC): | 2. Biological status assessment exists |
| Recovery potential/expectation: | Low - Combination or other (detail in comments) |
| National Monitoring Resource: | Opportunistic - insufficient |
| Species Comments: | Only ever recorded in the upper tidal zone of four English rivers (Arun, Medway, Tamar, Thames) & mainly lost through combination of river engineering & reduction in land management leading to vegetation succession (reeds & overhanging vegetation) |
Key Actions
Key Action 1
Proposed Action: Review success of recent introductions (particularly in River Tamar) & resurvey all lost sites to assess current state of vegetation etc.
Action targets: 2. Biological status assessment exists
Action type: Targeted monitoring
Duration: 1 year
Scale of Implementation: ≤ 10 sites
High priority sites: Tamar- Tavy Estuary SSSI Upper Arun SSSI? Tidal Arun & Medway.
Comments:
Key Action 2
Proposed Action: Undertake review of key sites to assess possibilities for landscape scale management (including tree felling, introduction of grazing, managed realignment etc.)
Action targets: 6. Recovery solutions trialled
Action type: Landscape/catchment/marine management
Duration: >10 years
Scale of Implementation: ≤ 5 sites
High priority sites: Tamar - Tavy Estuary SSSI
Comments: Principal reason that S. triqueter was lost from Tamar Estuary was due to reduced management (grazing) & use of riverside paths for towing, leading to growth of overhanging trees & spread of Common Reed etc.
Key Action 3
Proposed Action: Assess efficacy of establishing further colonies from ex situ material if suitable open habitat is deemed to still remain in key sites.
Action targets: 5. Remedial action identified
Action type: Ex situ conservation
Duration: 3-5 years
Scale of Implementation: Unknown
High priority sites: Tamar - Tavy Estuary SSSI
Comments: Habitat condition is key - it is though that some introductions have failed due to poor quality of habitat.
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.