SUMMARY
Arabis glabra (L.) Tower Mustard - Bwllpwllblod y ffwch BRASSICACEAE SYN.: Turritis glabra (L.)
Illustration by Fred Rumsey
STATUS Nationally Scarce. in Northern Ireland. The majority of UK BAP Priority Species since 1998. extinctions occurred in the 19th century 26 10-km squares post 1987. and the first half of the 20th century but losses continue. The current area OVERVIEW occupied by this species is only 15% of Arabis glabra is a tufted biennial herb of its total historic area. Much of its decline the cabbage family. The seedlings is probably due to the enclosure of germinate during the early spring, commons, the agricultural improvement develop into rosettes during the first of pastureland, urban development, summer and begin to elongate the forestry and the abandonment of following spring into towering stems up traditional management over the to 1m tall with numerous pale yellow remaining sites. These processes, flowers. Arabis glabra grows in a range particularly the latter, continue to of vegetation types characterized by threaten the few remaining sites. The occasional disturbance, usually on majority of extant sites are within the sandy, free-draining soils in the open. It Breckland and Severn & Avon Vales now occurs at only 31 sites in England, Natural Areas where Arabis glabra having become extinct at a further 263 occurs largely in the rides and clearings sites (250 in England, 12 in Scotland associated with early 20th century and 1 in Wales). It has never been found commercial forestry plantations on former open heath and grassland.
DISTRIBUTION Number of extant sites per vice county and a list of vice counties in which Arabis glabra is extinct:
ENGLAND EXTANT North Wiltshire 1 North Hampshire 2 Surrey 1 Middlesex 1 Berkshire 1 Buckinghamshire 1 East Suffolk 1 West Suffolk 4 East Norfolk 1 West Norfolk 8 Cambridgeshire 1 West Gloucestershire 2 Worcestershire 7 SUMMARY
EXTINCT North Somerset, West Sussex, East Kent, West Kent, South Essex, North Essex, Hertfordshire, Oxfordshire, Huntingdonshire, Northamptonshire, Warwickshire, Staffordshire, Shropshire, North Lincolnshire, Leicestershire, Nottinghamshire, Derbyshire, South Lancashire, North- east Yorkshire, South-west Yorkshire, Mid-west Yorkshire, Durham, South Northumberland, Westmorland, Cumberland. SCOTLAND EXTANT 0 EXTINCT Lanarkshire, Roxburghshire, East Lothian, West Perth, Mid Perth, East Perth, Angus, Dumbarton WALES EXTANT 0 EXTINCT Monmouthshire
MANAGEMENT Arabis glabra needs a sandy, drought- Study genetic diversity of Arabis prone soil on which vegetation cover glabra. develops slowly, subject to occasional Protect genetic diversity ex situ. disturbance to expose bare soil and buried seed. Disturbance should not be For a detailed profile of Arabis glabra so frequent as to destroy germinated view or download a copy of the full seedlings and no disturbance should be dossier also available from our Species carried out during the flowering and Dossier web page. seeding period. Plants retain seeds into the winter, so vegetation should not be CONTACTS cut too early, and cuttings should be Plantlife International removed. Successful conservation The Wild-Plant Conservation Charity measures have included radical 14 Rollestone Street disturbance by disc cultivation and Salisbury bulldozing, large-scale scrub clearance Wiltshire and intensive vegetation control. It is SP1 1DX likely that Arabis glabra has a persistent Tel. 01722 342730 seed-bank although the length of time for which seed remains viable, and Andy Byfield therefore that Arabis glabra might be [email protected] able to be reinstated at former sites, is Amanda Miller unknown. [email protected] Phil Wilson RECENT DEVELOPMENTS [email protected] The ecology and population dynamics of Arabis glabra are currently under Plantlife’s Back from the Brink (species investigation at the University of Sussex, recovery) programme is supported by and research is being conducted into English Nature, Scottish Natural Heritage seed biology and germination ecology at and the Countryside Council for Wales. Bath Spa University College. An experiment on the response of a Work on Arabis glabra is supported by: population of Arabis glabra to different cultivation regimes is also underway in Breckland.
RECOMMENDED FUTURE ACTION Maintain or reinstate management. Try to regenerate Arabis glabra at historic sites. Determine longevity of seed Compiled by Sarah Garnett bank. First draft dated 15 July 2004