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

Height (cm): 160

Perennation - primary


Life Form - primary




Clonality - primary

Little or no vegetative spread

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%)


JNCC Designations


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.