Cystopteris fragilis

Tracheophyta PteropsidaWoodsiaceaeCystopterisCystopteris fragilis


A fern of damp, shaded rock crevices, cliffs, cave entrances, ravines and mortared walls, always growing on a mineral-enriched substrate, and most frequent over limestone. It is also found on field boundary banks where water seeps from improved pasture, and in Fraxinus woodland. 0-1220 m (Breadalbanes, Mid Perth).



World Distribution

Circumpolar Wide-boreal element.

Broad Habitats

Inland rock (quarries, cliffs, screes)

Light (Ellenberg): 6

Moisture (Ellenberg): 7

Reaction (Ellenberg): 8

Nitrogen (Ellenberg): 4

Salt Tolerance (Ellenberg): 0

January Mean Temperature (Celsius): 2.6

July Mean Temperature (Celsius): 13.5

Annual Precipitation (mm): 1361

Height (cm): 20

Perennation - primary


Life Form - primary




Clonality - primary

Little or no vegetative spread

Count of 10km squares in Great Britain: 1118

Count of 10km squares in Ireland: 191

Count of 10km squares in the Channel Isles: 0

Atlas Change Index: -0.69

Weighted Changed Factor: -23

Weighted Change Factor Confidence (90%)


JNCC Designations


Atlas text references

Atlas (10a)
Grime JP, Hodgson JG, Hunt R
1988.  Comparative Plant Ecology.
Hultén E, Fries M
1986.  Atlas of north European vascular plants north of the Tropic of Cancer. 3 vols.
Jalas & Suominen (1972)
Jermy AC, Camus JC
1991.  The illustrated field guide to ferns and allied plants of the British Isles.
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.
Page CN
1997.  The ferns of Britain and Ireland, edn 2.