A tiny annual, growing on bare, often compacted, sandy or gravelly ground. It is often found on rutted tracks, paths and other areas where the ground is kept open by disturbance and periodic flooding. It can withstand only minimal competition from other vegetation. Lowland.
The British range of this species appears to be expanding. Since the 1962 Atlas it has become much more frequent in S.W. England and has colonised forestry rides in N.E. Scotland. In Cornwall, where it was not known until 1988, it is known from several car- and caravan-parks on sandy sites.
Light (Ellenberg): 8
Moisture (Ellenberg): 7
Reaction (Ellenberg): 4
Nitrogen (Ellenberg): 2
Salt Tolerance (Ellenberg): 0
January Mean Temperature (Celsius): 4.1
July Mean Temperature (Celsius): 16.2
Annual Precipitation (mm): 734
Count of 10km squares in Great Britain: 104
Count of 10km squares in Ireland: 0
Count of 10km squares in the Channel Isles: 11
Atlas Change Index: 0.86
Scarce Atlas Account
Crassula tillaea Lester-Garl.
This plant is restricted to open, bare sandy soils, of pH 5.0 to 6.1, often growing where there is a certain amount of compaction and hence occasional flooding in winter. It grows in heathland tracks, sandy tracks by the sea and in sandy areas used as car parks. Because of its small size, less than 5 cm in height and generally prostrate, it prefers places devoid of other vegetation. However, species found in the same vegetation include Agrostis capillaris, Aira praecox, Aphanes inexspectata, Carex arenaria, Erodium cicutarium, Festuca ovine, Hypochaeris radicata, Koeleria macrantha, Ornithopus perpusillus, Plantago coronopus, P. lanceolata, Rumex acetosella subsp. acetosella, Sagina apetala, Scleranthus annuus, Trifolium arvense, T. suffocatum and Hypnum cupressiforme (Trist 1979). It is a lowland plant, probably always occurring below 100 metres.
It is an annual, often bright yellow-green in the earlier part of the year, and turning a characteristic vivid red in summer. Reproduction is by seed.
Some sites have been lost in eastern England, especially at inland localities, because of heathland destruction. The species appears to have expanded its range in south-west England in recent years, with the discovery of many new sites in Dorset, some of them very substantial, and colonies in Somerset and Cornwall. This expansion may have been favoured by recent summer droughts and by the reduction in competition at coastal sites because of increased public pressure.
C. tillaea is found in the Mediterranean area, western Europe, north-west Germany and Macaronesia.
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.
Atlas text references
Flora dels Països Catalans, I. Introducció. Licopodiàcies-Capparàcies,
, Barcelona, (1984)
Flora of Cornwall,
, Camborne, (1999)
Jalas & Suominen (1999)
Scarce plants in Britain,
, Peterborough, (1994)