Osmunda regalis

Tracheophyta PteropsidaOsmundaceaeOsmundaOsmunda regalis


A large fern found on neutral or acidic substrates in fen-carr woodland and ditches, and on riverbanks and rocky lake shores. In W. Ireland it also grows in wet fields, mires and, more rarely, on limestone sea-cliffs. It is often confined to inaccessible sites in grazed areas. Lowland to 365 m in S. Kerry.



World Distribution

Suboceanic Southern-temperate element; also in E. Asia and N. America.

© P. Shannon

Broad Habitats

Light (Ellenberg): 6

Moisture (Ellenberg): 9

Reaction (Ellenberg): 5

Nitrogen (Ellenberg): 4


Salt Tolerance (Ellenberg): 0

January Mean Temperature (Celsius): 4.2

July Mean Temperature (Celsius): 14.5

Annual Precipitation (mm): 1225

Life form information

Height (cm): 160

Perennation - primary


Life Form - primary




Clonality - primary

Little or no vegetative spread

Distribution information

Count of 10km squares in Great Britain: 735

Count of 10km squares in Ireland: 576

Count of 10km squares in the Channel Isles: 4

Atlas Change Index: 0.56

Weighted Changed Factor: -19

Weighted Change Factor Confidence (90%)


Distribution information

JNCC Designations


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 (5b)
Hultén E, Fries M
1986.  Atlas of north European vascular plants north of the Tropic of Cancer. 3 vols.
Jalas & Suominen (1972)
Bangerter EB, Cannon JFM, Jermy AC
1978.  Ferns and their allies. The Island of Mull: a survey of its flora and environment. :12.1-12.7.
Marren PR
1999.  Britain's rare flowers.
Meusel H, Jäger E, Weinert E
1965.  Vergleichende Chorologie der zentraleuropäischen Flora. Volume 1. 2 vols.
Page CN
1997.  The ferns of Britain and Ireland, edn 2.