The lady fern (Athyrium filix-femina) is a much more delicate and graceful fern than the similar, but unrelated, male-fern. It forms dense clumps of its 'leaves' or fronds but with a much lower, almost rosette like, form. It is also slightly paler in colour than the male-fern and the fronds are usually much broader.
The lady fern is a native species and occasionally occurs throughout Dorset in damp woods, hedgerows, ditches and also amongst rocks and sometimes in marshes. Its liking to similar habitat as the male-fern makes it harder to tell them apart as there is the tendency to think that the lady fern is a developing male-fern when it is, in reality, a different species in its own right.
Armed with a magnifying glass and a good reference book there are other features that tell them apart from other ferns but I leave that for the specialists!
Once you have mastered the difference between these two plants you are well on the way to sorting Dorset's ferns out, just the two 'buckler ferns' to contend with after that. Most of the other ferns are are readily identifiable.