Gymnocarpium robertianum

Tracheophyta PteropsidaWoodsiaceaeGymnocarpiumGymnocarpium robertianum

Ecology

A deciduous fern of cracks, fissures and scree in limestone rock, but also found in shallow grikes of limestone pavement, and, rarely, on chalk. It prefers warm, sunny exposures but can tolerate light shading. It has become established as a garden escape on walls and culverts. Lowland to 585 m at Carreg yr Ogof (Carms.).

Status

Native

World Distribution

Circumpolar Boreo-temperate element, with a disjunct distribution.

© K.J. Walker, BSBI

Broad Habitats

Inland rock (quarries, cliffs, screes)

Light (Ellenberg): 7

Moisture (Ellenberg): 3

Reaction (Ellenberg): 8

Nitrogen (Ellenberg): 4

0

Salt Tolerance (Ellenberg): 0

January Mean Temperature (Celsius): 2.7

July Mean Temperature (Celsius): 14.6

Annual Precipitation (mm): 1168

Life form information

Height (cm): 45

Perennation - primary

Perennial

Life Form - primary

Non-bulbous geophyte (rhizome, corm or tuber)

Woodiness

Herbaceous

Clonality - primary

Rhizome far-creeping

Count of 10km squares in Great Britain: 113

Count of 10km squares in Ireland: 1

Count of 10km squares in the Channel Isles: 0

Atlas Change Index: -0.37

Distribution information

JNCC Designations

NBNSYS0000002084

Scarce Atlas Account

Scarce Atlas Account: 

Gymnocarpium robertianum (Hoffm.) Newman

Limestone fern

Status: scarce

 

 

This fern is confined to calcium-rich substrates and usually grows on natural limestone screes and pavement. It is usually found on Carboniferous and oolitic limestone, but there is at least one locality on hard chalk. It is favoured by open sunny situations, although it may get established in shady grikes. G. robertianum is associated with other limestone species such as Asplenium viride, Cystopteris fragilis, Geranium robertianum, Mercurialis perennis, Oxalis acetosella and Phyllitis scolopendrium. It rarely grows above 450 metres altitude, but reaches 585 metres on Carreg yr Ogof in the Black Mountains.

This perennial species is easily grown from spores and is a favourite with fern gardeners. It often escapes and establishes itself on man-made walls and in culverts even in the drier and colder parts of the country.

In its natural habitats G. robertianum can be ousted by competition with Mercurialis perennis and hawthorn scrub, and limestone quarrying has taken its toll of its localities. 

This is a circumboreal species. In Europe it is most frequent in central Europe, extending south to the Pyrenees and north to northern Norway (Jalas & Suominen 1972).

 

 

A. C. Jermy

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 (14d)
The Irish Red Data Book. 1. Vascular Plants,
Curtis, T. G. F., and McGough H. N.
, Dublin, (1988)

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

Jalas & Suominen (1972)
Ferns and their allies,
Bangerter, E. B., Cannon J. F. M., and Jermy A. C.
, The Island of Mull: a survey of its flora and environment, London, p.12.1-12.7, (1978)

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

The ferns of Britain and Ireland, edn 2,
Page, C. N.
, Cambridge, (1997)

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