HART'S TONGUE FERN : Asplenium scolopendrium
The only British fern with undivided fronds has glossy, tapering, evergreen leaves. Look for spore cases arranged in parallel rows of slits on the underside. It can be found against rocks and logs.
The fronds contain compounds that are used in medicines and cosmetics. These range from astringents and cough medicines, to treatment of high blood pressure and for healing wounds; even treatments .for dysentery, diarrhoea and digestive problems
New fronds appear in April and begin to unfurl. These are called fiddleheads - obviously.
After a few days their tongue-like shape becomes more apparent.
And by mid-May they are doing well.