Crassula tillaea

Ecology

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.

Status

Native

World Distribution

Submediterranean-Subatlantic element.

© K.J. Walker, BSBI

Broad Habitats

Boundary and linear features (eg hedges, roadsides, walls)

Light (Ellenberg): 8

Moisture (Ellenberg): 7

Reaction (Ellenberg): 4

Nitrogen (Ellenberg): 2

0

Salt Tolerance (Ellenberg): 0

January Mean Temperature (Celsius): 4.1

July Mean Temperature (Celsius): 16.2

Annual Precipitation (mm): 734

Life form information

Height (cm): 5

Perennation - primary

Annual

Life Form - primary

Therophyte (annual land plant)

Woodiness

Herbaceous

Clonality - primary

Little or no vegetative spread

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

Distribution information

JNCC Designations

NHMSYS0000457663

Scarce Atlas Account

Scarce Atlas Account: 

Crassula tillaea Lester-Garl.

Mossy stonecrop

Status: scarce

 

 

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.

 

 

L. Farrell

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

Atlas (135c)
Flora dels Països Catalans, I. Introducció. Licopodiàcies-Capparàcies,
de Bolòs, O., and Vigo J.
, Barcelona, (1984)

Flora of Cornwall,
French, C. N., Murphy R. J., and Atkinson M. G. C.
, Camborne, (1999)

Jalas & Suominen (1999)
Scarce plants in Britain,
Stewart, A., Pearman D. A., and Preston C. D.
, Peterborough, (1994)