Sedum forsterianum (Rock Stonecrop)

Ecology

A mat-forming perennial herb of open, dry, well-drained habitats, including rocks and screes, wooded cliffs and gullies. Naturalised colonies are found in churchyards, on waste ground, mine waste, walls and railway land. Lowland to 600 m as native (Llyn y Fan Fach, Carms.).

Status

Native

World Distribution

Oceanic Southern-temperate element.

Broad Habitats

Light (Ellenberg): 7

Moisture (Ellenberg): 3

Reaction (Ellenberg): 5

Nitrogen (Ellenberg): 1

0

Salt Tolerance (Ellenberg): 0

January Mean Temperature (Celsius): 3.6

July Mean Temperature (Celsius): 14.8

Annual Precipitation (mm): 1239

Life form information

Height (cm): 20

Perennation - primary

Perennial

Life Form - primary

Chamaephyte

Woodiness

Herbaceous

Clonality - primary

Extensively creeping and rooting at nodes

Clonality - secondary

Irregularly fragmenting (mainly water plants)

Count of 10km squares in Great Britain: 122

Count of 10km squares in Ireland: 0

Count of 10km squares in the Channel Isles: 0

Atlas Change Index: 1.54

Distribution information

JNCC Designations

NHMSYS0000463386

Scarce Atlas Account

Scarce Atlas Account: 

Sedum forsterianum Smith

Rock stonecrop

Status: scarce

 

This is a very local species occurring on rocks and screes. It can grow in open, dry situations, or in wet woodland. In Britain the more usual habitat is open rock faces and broken cliffs, often near the sea. It is found in open grassland communities and occurs with other rare or scarce species, including Helianthemum apenninum, Inula conyza, Scilla autumnalis and Trinia glauca. Its commoner associates include Dactylis glomerata, Festuca ovina, Koeleria macrantha, Pilosella officinarum, Plantago lanceolata, Sedum acre, S. album and Thymus polytrichus. It is grown as a rockery plant in gardens and over graves in churchyards, and it has occasionally become established in the wild from discarded stock.  The altitudinal range of S. forsterianum is from sea level on the west coast to 600 metres at Llyn-y-fan Fach in the Black Mountains.

It is a perennial plant with creeping stems forming mats. Short ascending stems are sterile, whilst flowering stems are much longer. It is known to spread vegetatively.

S. forsterianum seems to have become more common throughout its western range. It may have benefited from increased grazing as it can easily spread into open ground by broken-off stems, and it is not palatable.

In Europe it has an essentially western distribution, occurring from southern Spain north to Britain, and it is often found in damper situations than in Britain. It is also reported from Morocco. 

Populations are variable and it was previously thought that two subspecies could be recognised. They have not been maintained by Stace (1991).

 

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 (134d)
A flora of Norfolk,
Beckett, G., Bull A., and Stevenson R.
, (1999)

Atlas of north European vascular plants north of the Tropic of Cancer. 3 vols,
Hultén, E., and Fries M.
, Königstein, (1986)

Jalas & Suominen (1999)
Vergleichende Chorologie der zentraleuropäischen Flora. Volume 1. 2 vols,
Meusel, H., Jäger E., and Weinert E.
, Jena, (1965)

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