2 Dryopteris Athyrium and Polystichum
Three groups of ferns (genera), commonly found in British gardens have fronds of the bipinate type. That is to say the fronds are divided into side branches, which themselves have leaves down their edges. If the small leaves (pinnules), are roughly symmetrical in outline, as in 3 and 4 below, then you will have either Dryopteris or Athyrium. However if the leaves have “thumbs” on one edge,but only one edge, as in 1 and 2 (circled), then you have a Polystichum type.
If you have a Polystichum it is almost certain to be one of the British natives, almost certainly P. setiferum the Soft Sheild Fern,(Picture) though very rarely it may be P. aculeatum. These two however are very hard to tell apart and best left to a person of some experience. Sometimes also you may find exotic Polystichums in British gardens especially Polystichum munitum the American Sword Fern. This is easy to identify as it has long narrow simple leaflets, making it look palm like, and is the plant at number 2 in the picture.
If you do not have a Shield Fern, Polystichum. You will probably have either a Male Fern, Dryopteris or an Athyrium, known as Lady Ferns. In the Male Ferns the sides of the small leaves are straight or wavy, as in number 4 above; but those of the lady ferns are deeply cut, as in number 3 above.You may also like to check the sporing bodies, which you will find on the backs of the frond in summer. If these are a plump, rounded, kidney shape, you are sure to have a Dryopteris, either Dryopteris filix-mas the Male Fern or D. affinis the False Male Fern.(Picture) While if they are a long comma or hocky stick shape you have an Athyrium.(Picture)
You may just have Matteuccia strulthiopteris the Shuttlecock Fern in your garden. As this foreign species has been in British gardens for some years. It is easy to recognize for three reasons. Firstly it is a large fern, with a strong shuttlecock form. That is to say like an inverted and very geometric cone, quite unlike the roughly circular crowns of most ferns; with even a short "trunk" at the base. Secondly it tends to like moist places where it spreads underground, and sends up another crown at intervals. These two characters of growth are so strong and distinct that it would be hard to mistake it for any other fern. While thirdly it has a habit of sending up a small second ring of fronds inside the first, which soon turn brown, for these are, in fact, the spore bearing structures of this fern, although not found on all plants they are as good as a label.
There is just a faint possibility that you may have one other British native fern in your garden , especially if you have a moist place. This is the Royal Fern, or Osmunda regalis. This is a large fern of moist ground and quite striking appearance. Having some fronds with seperate sporing clusters, like dead Dock flowers at there tips. These are large and easy to spot, and you should not mistake Royal Fern for any thing else, see picture below.
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