Weissia multicapsularis

Recent work by Werner et al. (2005) showed W. multicapsularis to be genetically distinct from W. longifolia by using nrITS sequence data.

The species is known from two small subpopulations in the wild, both in Cornwall, England. It is considered Extinct in France (one historic population). W. multicapsularis is a European endemic.

The species is listed as Critically Endangered because it has such a small range and tiny population, all outside of protected areas, and is highly sensitive to changes in land-management practices. The subpopulation in France has already been lost and the species could easily disappear from the UK localities.

The species is found at two locations separated by about 55 km on the south coast of Cornwall:

Talland Bay: 3 – 4 subpopulations over approx. 200 m.

Portscatho: 3 subpopulations over a 500 m linear stretch.

Short open grassland or bare ground on free-draining, summer-droughted, non-calcareous circumneutral loamy soils and on top of soil-capped field walls (‘Cornish hedges’) mostly coastal. Contrary to statements that  W. multicapsularis is a dynamic colonist, it is now understood to behave as a perennial stayer and is faithful to sites, persisting if the niche is maintained.

Neglect (lack of grazing), competition from vascular plant growth and other bryophytes, nutrient enrichment and scrub encroachment are severe and increasing threats.

Portscatho: small-scale hand-clearance of grass on top of soil-capped walls.

Talland Bay: currently grazed by ponies which will help to keep grassland open and disturbed.

Material from Talland Bay is in ex situ cryopreservation facility (Royal Botanic Gardens Kew).