Ferns

Of the 82 species of true ferns listed, fully 30% are exotic alien species, of which just a handful have become established in the wider landscape. Some of these aliens have the barest toehold as wild plants in Britain, often only surviving within the confines of larger towns and cities of southern England. None exemplify this better than the genera Adiantum and Pteris, members of which can occasionally be found growing on the shaded walls of townhouse basements, in dank drain grates and beneath leaky gutters. Many folk would look upon this guild of species with a degree of disdain, regarding them perhaps as mere plastic dross, whereas I find it all rather exciting. But then I do enjoy the whole concept of slum botany (or grotany as I've heard it called), often because you literally have no idea what might be growing through the nearest paving crack, halfway up a drainpipe, or beneath a hanging basket. It's a niche interest I agree, but I love it. 

A jumble of fern species in a damp, shaded spot to the rear of an old church

The remaining 70% are natives, but even here things are far from simple. Male-ferns in the genus Dryopteris used to comprise three species. Ongoing genetic work has proven this number to be nearer eight species, and quite likely more cryptic species will be discovered as work continues. Subspecies for some have been raised to species rank, whilst others are retained at subspecies level. Oh, and hybrids occur, all of which leaves we amateurs in a rightful state of confusion. Likewise the genus Athyrium has become more complicated than it used to be. I've followed recent works for the most part, have presumed to split out one or two species where I feel it is warranted, and doubtless will make a huge hash of identifying them as the season progresses. But I will persevere, it will be educational and maybe even fun...

Skye is a fabulous place for getting amongst ferns, the nearby mainland offers several more species and the mountains further inland offer opportunities to become better acquainted with even more of these wonderful plants. Yet there are many species that only occur far to the south of me, necessitating long journeys should I wish to meet them. It may require a bit of jiggery-pokery, but I should be able to combine various rush and sedge target species into any such ferny jollies south of the border, in order to make such a trip truly memorable. 

Irish Spleenwort is entirely restricted to Ireland whilst Jersey Fern occurs on the Channel Islands but not in Britain. As such, neither of these species will feature any further in this blog. 

Woodwardia radicans naturalised in a Cornish churchyard

There are a whole plethora of terms I need to understand and become familiar with: crosiers, indusia, annulus, sori, pinnulets, indurated cells, rachis, sporangia... There may be occasions where I become so befuddled and irate with myself that I shall simply walk away from a number of the ferns I'm attempting to identify. But with time, plus several keys and a handlens, I should be able to make headway with many of them. Dryopteris will be a bit of a nightmare, I'm quite sure of that. But at least I'll be smug in the knowledge that others far better than I can't wrap their head around them either. 

My journeys onto the mainland will see me drive past James Merryweather's house. I might see if he fancies coming out with me from time to time...

Species available (lifers in red) with a hyperlink to the relevant blog page alongside

Royal Fern	Osmunda regalis
Tunbridge Filmy-fern	Hymenophyllum tunbrigense
Wilson's Filmy-fern	Hymenophyllum wilsonii
Veined Bristle-fern	Trichomanes venosum
Killarney Fern	Trichomanes speciosum
Pillwort	Pilularia globulifera
Water Fern	Azolla filiculoides
Australian Tree-fern	Dicksonia antarctica
Bracken	Pteridium aquilinum
Pinewood Bracken	Pteridium pinetorum
Pig-fern	Hypolepsis ambigua
Parsley Fern	Cryptogramma crispa
Delta Maidenhair Fern	Adiantum raddianum
American Maidenhair Fern	Adiantum pedatum
Maidenhair Fern	Adiantum capillus-veneris
Ladder Brake	Pteris vittata
Eastern Spider Brake	Pteris multifida
Ribbon Fern	Pteris cretica
Spider Brake	Pteris incompleta
Tender Brake	Pteris tremula
Jungle Brake	Pteris umbrosa
Oak Fern	Gymnocarpium dryopteris
Limestone Fern	Gymnocarpium robertianum
Brittle Bladder-fern	Cystopteris fragilis
Upland Brittle Bladder-fern	Cystopteris pseudoregia
Alpine Bladder-fern	Cystopteris alpina
Greenish Bladder-fern	Cystopteris diaphana
Dickie's Bladder-fern	Cystopteris dickieana
Mountain Bladder-fern	Cystopteris montana
Hart's-tongue	Phyllitis scolopendrium
Jackson's Spleenwort	X Asplenophyllitis jacksonii
Confluent Spleenwort	X Asplenophyllitis confluens
Black Spleenwort	Asplenium adiantum-nigrum
Sea Spleenwort	Asplenium marinum
Lanceolate Spleenwort	Asplenium obovatum
Maidenhair Spleenwort	Asplenium trichomanes
Green Spleenwort	Asplenium viride
Wall-rue	Asplenium ruta-muraria
Forked Spleenwort	Asplenium septentrionale
Rustyback	Ceterach officinarum
Marsh Fern	Thelypteris palustris
Beech Fern	Phegopteris connectilis
Lemon-scented Fern	Oreopteris limbosperma
Oblong Woodsia	Woodsia ilvensis
Alpine Woodsia	Woodsia alpina
Lady-fern	Athyrium filix-femina
Alpine Lady-fern	Athyrium distentifolium
Newman's Lady-fern	Athyrium flexile
Hard-fern	Blechnum spicant
Antarctic Hard-fern	Blechnum penna-marina
Chilean Hard-fern	Blechnum cordatum
Chain Fern	Woodwardia radicans
Ostrich Fern	Matteuccia struthiopteris
Sensitive Fern	Onoclea sensibilis
Japanese Shield-fern	Polystichum polyblepharum
Soft Shield-fern	Polystichum setiferum
Hard Shield-fern	Polystichum aculeatum
Holly-fern	Polystichum lonchitis
Korean Rock-fern	Polystichum luctuosum
Western Sword-fern	Polystichum munitum
House Holly-fern	Cyrtomium falcatum
Fortune's Holly-fern	Cyrtomium fortunei
Shaggy Shield-fern	Dryopteris cycadina
Mountain Male-fern	Dryopteris oreades
Common Male-fern	Dryopteris filix-mas
Elegant Male-fern	Dryopteris lacunosa
Golden Scaly Male-fern	Dryopteris affinis
Borrer's Scaly Male-fern	Dryopteris borreri
Narrow Scaly Male-fern	Dryopteris cambrensis
Scottish Male-fern	Dryopteris pseudocomplexa
Alpine Male-fern	Dryopteris pseudodisjuncta
Japanese Buckler-fern	Dryopteris erythrosora
Hay-scented Buckler-fern	Dryopteris aemula
Rigid Buckler-fern	Dryopteris submontana
Crested Buckler-fern	Dryopteris cristata
Narrow Buckler-fern	Dryopteris carthusiana
Broad Buckler-fern	Dryopteris dilatata
Northern Buckler-fern	Dryopteris expansa
Polypody	Polypodium vulgare  Link
Intermediate Polypody	Polypodium interjectum
Southern Polypody	Polypodium cambricum
Kangaroo Fern	Phymatosorus diversifolius