Glaucous Beard-moss (Didymodon glaucus)

Key Details

Taxonomic Groups: Non-vascular plant (incl. chromists) > moss > Moss
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: Didymodon glaucus
UKSI Recommended Authority: Ryan
UKSI Recommended Qualifier: (none specified)
Red List Citation: Callaghan, 2023
Notes on taxonomy/listing: (none)

Criteria

Question 1: Does species need conservation or recovery in England?
Response: Yes
Justification: At risk of extinction in England due to small population size
Question 2: Does recovery/ conservation depend on species-specific actions?
Response: Yes
Justification: A species with low recovery potential where the main aim is to maintain/protect populations, though reintroduction to a former region may be possible
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: The species has a restricted distribution and so is unlikely to benefit from untargeted actions

Species Assessment

Current step on the Species Recovery Curve (SRC): 6. Recovery solutions trialled
Recovery potential/expectation: Medium-high
National Monitoring Resource: Opportunistic - insufficient
Species Comments: GB RL criteria: D1. Temperate European species. Continue to maintain suitable habitat at its only known location (SSSI) in Britain.

Key Actions

Key Action 1

Proposed Action: Assess feasibility and develop a plan for reintroduction to Sussex

Action targets: 6. Recovery solutions trialled

Action type: (Re-)introduction

Duration: 1 year

Scale of Implementation: 1 site

High priority sites:

Comments: Presently limited to a single small population inside a SSSI, which has a management plan for the species and is subject to periodic habitat management. Historically known from Sussex, where reintroduction may be a possibility.

Key Action 2

Proposed Action: Develop ex situ cultivation for use in reintroduction trial

Action targets: 6. Recovery solutions trialled

Action type: Ex situ conservation

Duration: 3-5 years

Scale of Implementation: Not applicable

High priority sites:

Comments: In vitro culture is in cryopreservation at Kew from material collected from North Wiltshire, but cultivated material is needed for reintroduction trial

Key Action 3

Proposed Action: Undertake research to better understand the ecology and habitat requirements of the species.

Action targets: 4. Autecology and pressures understood

Action type: Scientific research

Duration: 1 year

Scale of Implementation: National

High priority sites:

Comments: Review what is known of the species to inform reintro.

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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.