An annual of open heathland habitats, growing on sandy and peaty soils of relatively high base-status which are damp in winter and spring; it is also found in damp pasture, woodland rides, dune-slacks and on cliffs. Reduced competition, caused by winter-flooding, grazing and disturbance, is essential. Lowland.
The 1962 Atlas showed major losses before 1930, especially in Cornwall, and this species has declined further in areas such as Dorset. It is threatened at many sites because of the lack of grazing and the upgrading of heathland tracks with hardcore. In west Britain and Ireland, however, local losses may have been balanced by newly discovered sites.
Light (Ellenberg): 9
Moisture (Ellenberg): 8
Reaction (Ellenberg): 3
Nitrogen (Ellenberg): 2
Salt Tolerance (Ellenberg): 0
January Mean Temperature (Celsius): 5.4
July Mean Temperature (Celsius): 15.6
Annual Precipitation (mm): 1063
Count of 10km squares in Great Britain: 66
Count of 10km squares in Ireland: 37
Count of 10km squares in the Channel Isles: 5
Atlas Change Index: -0.7
Scarce Atlas Account
Cicendia filiformis (L.) Delarbre
C. filiformis is a diminutive annual of heathlands on sods which have a relatively high base status and are damp in winter and spring. It is most frequently associated with winter-flooded pools, cart tracks and ditches, but also very locally abundant in heavily grazed damp pasture. Such sites are usually on mildly acid, base-rich clays (e.g. New Forest and Dorset) or loess overlying serpentine and gabbro (Lizard Peninsula). At one site on the Lizard Peninsula it is associated with serpentine erosion pans and rock outcrops. Reduced competition is essential: this is effected by winter flooding, high levels of rough grazing, and disturbance. It is often found with many other rare and local species, suggesting the great age, and continuity of management, of such habitats. At the Lizard Peninsula, associates on rutted tracks include Juncus pygmaeus, Pilularia globulifera, Ranunculus tripartitus and Chara fragifera. On the sand and clay heaths of south-central England, Anagallis minima, Chamaemelum nobile, Galium constrictum, Illecebrum verticillatum, Ludwigia palustris, Mentha pulegium and Radiola linoides also occur.
C. filiformis is a short-lived summer annual, germinating in spring on bare ground exposed after winter flooding. Like many such annuals, it may be extremely abundant over small areas during favourable seasons, but absent in other years.
Many sites have been lost by the extensive destruction of heathland or by infilling or drainage of its favoured microhabitats. Now that most extant sites are SSSIs or nature reserves, the greatest threat arises from lack of suitable management. Stock grazing is especially critical: in its absence C. filiformis soon disappears as succession to grassland and scrub occurs. Thus with the cessation of grazing and other traditional management practices over many of the heathland districts of lowland Britain, the range of C. filiformis has contracted severely. Another threat lies in the upgrading of heathland tracks to improve access for vehicles. Today the plant is only widespread on the Lizard Peninsula and in the New Forest. In former strongholds, such as Dorset, it is likely to appear only at rare intervals following chance disturbance unless traditional management practices are reinstated.
C. filiformis is most widespread in western Europe south to the Mediterranean, and is also found in the Azores, North Africa and western Turkey.
A. J. Byfield
PLANTATT - Attributes of British and Irish plants. (.zip 1455KB) This dataset was compiled and published in 2004, and last updated in November 2008. Download includes an Excel spreadsheet of the attributes, and a PDF explaining the background and nomenclature. Note that the PDF version is the booklet as published, whereas the Excel spreadsheet incorporates subsequent corrections. A hardcopy can be purchased from the Centre for Ecology and Hydrology.