Red Star-thistle (Centaurea calcitrapa)
Key Details
| Taxonomic Groups: | Vascular plant > flowering plant > Herbaceous plant |
| Red List Status: | Critically Endangered (Not Relevant) [CR(nr)] |
| D5 Status: | |
| Section 41 Status: | (not listed) |
| Taxa Included Synonym: | (none) |
| UKSI Recommended Name: | Centaurea calcitrapa |
| 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: | Undergoing long-term, strong decline. |
| Question 2: | Does recovery/ conservation depend on species-specific actions? |
| Response: | Yes |
| Justification: | This is plant which seems to respond best to hard grazing which creates bare ground for germination and reduces competition faced by the flat-growing, resilient, first-year rosette. Many lost sites are considered the result of casual introduction as a seed or shoddy contaminant, and this pathway to establishment of new populations is increasingly unavailable. |
| 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: | This species would not benefit from untargeted management |
Species Assessment
| Current step on the Species Recovery Curve (SRC): | 5. Remedial action identified |
| Recovery potential/expectation: | Medium-high |
| National Monitoring Resource: | Combination - insufficient |
| Species Comments: |
Key Actions
Key Action 1
Proposed Action: Establish a database of all known current and recent sites, to include information on population size, any recent change in population size, causes of loss where this has occurred, any known recent recruitment to the population, current protection and management measures at each site, and the potential for expansion or restoration of the population within the site.
Action targets: 5. Remedial action identified
Action type: Status survey/review
Duration: 2 years
Scale of Implementation: ≤ 20 sites
High priority sites:
Comments:
Key Action 2
Proposed Action: Where data gathered under action 1 indicates a recent decline in population, or where a local population has been lost within the last approx. 10 years, ensure that a suitable system of grazing and/or ground disturbance is established and/or maintained.
Action targets: 5. Remedial action identified
Action type: Habitat management
Duration: 3-5 years
Scale of Implementation: ≤ 10 sites
High priority sites: Sussex, Kent, Leeds, where there are current or recent persistent populations.
Comments: The related Centaurea solstitialis has been shown to have an average seed longevity in the soil of 6-10 years.
Key Action 3
Proposed Action: Carry out experimental work to establish the species' longevity in the soil seed bank. This should involve work at sites where the plant previously occurred and where the date of last occurrence is known: on this sites, trial plots should be cleared of vegetation and disturbance carried out both shallowly (up to 10cm) and to a depth of up to 30cm.
Action targets: 5. Remedial action identified
Action type: Scientific research
Duration: >10 years
Scale of Implementation: ≤ 5 sites
High priority sites:
Comments: This action aims to inform possible programmes for re-establishment of the species at sites where formerly present. It is intended to test for the presence and/or viability of shallowly buried and deeply buried seed.
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.