Key to Common British Native Ferns

By Adrian Dyer and Alison Evans
Photographs Roger Golding


This identification key covers the most common and widespread fern species native to Britain and Ireland. There are in addition some very rare species that are unlikely to be found by any but the most committed fern hunters. These are listed in the Appendix

If you need help in using a key, there are instructions here

A list of the ferns included in the key is available here

Further details for identifying all these species are given in Merryweather (2020), Hutchinson and Thomas (1996); Page (1997); and Merryweather (2005, 2007). Assistance with the more difficult identifications may be obtained from The Plant Crib (Rich, T.C.G and Jermy, A.C., 1998, published by BSBI)

Although now recognised as the closest relatives of ferns, all horsetails have been omitted from this key. Most published identification aids include the 8 horsetail species and their several hybrids, but their structure, and their diagnostic characters, are very different from ferns and beginners are advised to take one step at a time and become familiar with one group before tackling the other.

Access the Key here

It is important to choose mature, fertile fronds. If taking a frond for identification, take the full length of the stipe. Avoid fronds that are sterile (i.e. are not producing spores), damaged or are smaller than the majority of fronds present. With practice, ferns can often be identified from sterile fronds, but beginners will find this more difficult


Hutchinson, G. and Thomas, B. A. (1996) Welsh ferns. National Museums and galleries of Wales, Cardiff.
Jermy, C. and Camus, J. (1991) The Illustrated Field Guide to Ferns and Allied Plants of the British Isles. Natural History Museum, London.
Merryweather, J. (2005) Key to Common ferns. Field Studies Council,Shrewsbury.
Merryweather, J. (2007a) The Fern Guide. Field Studies Council, Shrewsbury.
Merryweather, J. (2020) Britain’s Ferns, Clubmosses, Quillworts, and Horsetails. A field guide. Princeton WILDguides. ISBN 9780691180397
Page, C. N. (1997) The Ferns of Britain and Ireland. Second Edition. CUP, Cambridge.

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