[3] It is most abundant in Ireland, southwestern Great Britain, western France and northwest Iberia, where it benefits from the combination of mild winters and moist summers, but also occurs more locally north to northern Scotland and east to the Crimea and Turkey; in the Mediterranean it usually grows at high altitudes.

The fronds are soft-textured, bipinnate (single-pinnate on small, young plants), with the pinnae opposite on the stalk.

They live for nine to fifteen months and remain attached to the rhizome after withering.

The round sori occupy two rows on either side of the midrib of each pinnule and are covered by a centrally-attached, umbrella-like indusium with fringed edges.

[4] The following cultivars have gained the Royal Horticultural Society's Award of Garden Merit:[5]