Frankenia laevis

Tracheophyta MagnoliopsidaFrankeniaceaeFrankeniaFrankenia laevis

Ecology

A mat-forming perennial herb of saltmarshes and saltmarsh-sand dune transitions, especially where firm sand or silt overlies coarser grained material; also rarely on shingle beaches and chalk sea-cliffs. Lowland.

Status

Native

World Distribution

Suboceanic Southern-temperate element.

Broad Habitats

Light (Ellenberg): 9

Moisture (Ellenberg): 8

Reaction (Ellenberg): 8

Nitrogen (Ellenberg): 5

5

Salt Tolerance (Ellenberg): 5

January Mean Temperature (Celsius): 4.4

July Mean Temperature (Celsius): 16.5

Annual Precipitation (mm): 680

Life form information

Height (cm): 8

Perennation - primary

Perennial

Life Form - primary

Chamaephyte

Woodiness

Herbaceous

Clonality - primary

Little or no vegetative spread

Count of 10km squares in Great Britain: 58

Count of 10km squares in Ireland: 0

Count of 10km squares in the Channel Isles: 5

Atlas Change Index: 0.03

Distribution information

JNCC Designations

NBNSYS0000002982

Scarce Atlas Account

Scarce Atlas Account: 

Frankenia laevis Lo                    

Sea-heath

Status: scarce

 

 

F. laevis is a prostrate, wiry perennial which occupies a particular zone in English salt marshes, where the wet silt of the marsh proper gives way to the dry sand of adjacent dunes and beaches. In Norfolk, transitional vegetation of this kind is also the primary habitat of Limonium bellidifolium. More rarely, F. laevis is found on shingle and, in Kent, at the foot of chalk cliffs, forming a turf on eroded ledges within the splash zone. Being strictly coastal, F. laevis reaches a maximum altitude of 5 metres on the cliffs near Dover.

F. laevis can spread vegetatively, the procumbent shoots rooting to produce new individuals. In localities where populations are small and plants somewhat isolated only 10% of the flowers produce capsules containing seed; in larger and denser populations over half the flowers produce seeds. The average number of seeds set per flower is also higher in larger populations. Germination probably occurs in the spring.

F. laevis has declined in eastern England, due to disturbance of salt marshes and their destruction through improved sea-defences, urbanisation and industrial development. F. laevis is, rather surprisingly, grown as a rock-garden plant and sometimes escapes from cultivation to become established in coastal habitats. In Dorset it has become well naturalised in recent years on bare clay cliffs. The species was first recorded in Wales in 1965 on an Anglesey salt-marsh, where the population increased gradually over the next ten years (Roberts 1975). It has subsequently been found in Glamorgan (Waldren 1982). It is not known whether these populations are garden escapes, but they are treated as introductions on the map.

It is a species of the coasts of Western Europe and the Mediterranean, from Norfolk to south-east Italy. F. laevis also occurs on the adjacent coast of North Africa and in Macaronesia. 

For a detailed account of the ecology of this species, including a map of its European distribution, see Brightmore (1979).

 

J. O. Mountford

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 (61b)
de Bolòs O, Vigo J
1990.  Flora dels Països Catalans, II. Crucíferes-Amarantàcies.
Brightmore D
1979.  Biological Flora of the British Isles. No. 146. Frankenia laevis L. Journal of Ecology. 67:1097-1107.
Newcombe M
1991.  Sea Heath and other plants on a degraded cliff face. Transactions of the Kent Field Club. 11(2):93.
Stewart A, Pearman DA, Preston CD
1994.  Scarce plants in Britain.