Ferns Archives - James Common

Growing Ferns from Spores – Part 1

It will come as no surprise to readers of this blog that I’ve developed a slight obsession with ferns of late, centred on both tracking down and identifying wild ones and growing them at home. Despite that, I hadn’t yet tackled the seemingly difficult process of growing ferns from spores. At least, not until this year.

Fern Biology

Ferns are among our most primitive plants, and their reproduction, while fascinating, is less sophisticated than that of flowering plants. Cutting a long story short, spores are produced on the underside of the frond in structures called sori (or a sorus if referring to just one).

Ferns are interesting in that they have two distinct life stages. The first is the gametophyte, or sexual stage, in which the spores grow into a curious, shield-like structure called a prothallus. It looks a bit like a tiny green fish scale and, in truth, rather resembles a bryophyte, but with minute pockets that hold the egg and sperm. When conditions are right, fertilisation takes place, with sperm swimming through water droplets to reach the egg of another prothallus. Only after this stage does what we think of as a “proper” fern develop, as the plant enters the second phase of its lifecycle.

Keen to try this myself – and having sufficiently swotted up with a range of fantastic resources online [here] and [here] – I decided to give it a go this summer. Time for an update!

Lemon-scented Fern *Oreopteris limbosperma* showing ripe spores in the pinnule margins

Gathering Spores

Ferns produce spores at different times of the year, though most seem to be ready between June and September. It’s fairly easy to tell when they’re ripe: in most species, the sporangia curl back or fall off entirely, revealing brown, yellow, or even black dust – the spores. Gathering them is incredibly simple. You can either tap a fertile frond over a paper envelope or collect a small section of the frond; a little goes a long way. If you choose the latter, it’s best to let it dry on some paper for a few hours, after which you’ll notice the spores beginning to fall and gather on the surface.

For this little experiment, I gathered spores from a mix of cultivated plants growing in the garden including Brittle Bladder-fern Cystopteris fragilis, Rustyback Asplenium ceterach, Soft Shield-fern Polystichum setiferum, Scaly Buckler-fern Dryopteris remota, and Beech Fern Phegopteris connectilis; as well as a few common wild species growing in public spaces (remember, you need permission to collect even the smallest hint of plant material from private land). In the end, this meant I collected spores from Western Scaly Male-fern Dryopteris affinis subsp. affinis, Borrer’s Male-fern Dryopteris borreri, and Maidenhair Spleenwort Asplenium trichomanes too.

Sowing the Spores

Having gathered our spores, it was time to sow them. This, it seems, is the stage you really need to get right. First, you need an airtight container that seals in moisture and provides the humidity required for the spores to germinate (we used a multipack of cheap plastic Tupperware). Secondly, you need a fine, sterilised compost. We opted for a fine seed compost, zapped in the microwave for three minutes to kill any nasties lurking in the soil. Other sources suggest that pouring boiling water through the compost or placing it in the oven works just as well.

With your materials prepared, all that remains is to sprinkle on your spores, give them a good spritz of water, label the container, and replace the lid before leaving it somewhere bright for nature to run its course. In our case, we placed all our containers under fluorescent grow lights used for our houseplants.

Watch and Wait

Next comes the hard part: ignoring your containers until you notice signs of life. I didn’t manage this perfectly, which may explain some of the problems mentioned later in this post. Generally, sources online suggest that different ferns take varying amounts of time before any activity becomes visible. I was pleasantly surprised that after only a month, each of our test containers hosted a fine, green, algae-like film spreading across the soil. This was the first sign that our spores were starting to grow into prothalli.

Beech Fern *Phegopteris connectilis* forming prothalli after one month under supplimentary light

Watch the Prothalli Grow

Eventually, after a variable amount of time depending on the species (around three to four months for most of ours), the initial green, algae-like growth began to transform into the shield-like structures recognisable as prothalli. At this stage, the fern grows its first roots and begins to photosynthesise, and it is also the point at which the all-important fertilisation happens, if you’re successful. To help with this, sources recommend a regular spritz of water to aid cross-fertilisation, something that would normally be provided by rain outdoors but must be administered manually when growing ferns indoors. The photos below show a range of more advanced prothalli.

After some time, these prothalli develop into the sporophyte generation, the form we most closely associate with ferns.

Borrer’s Male-fern *Dryopteris borreri* prothalli

The rather large prothalli of Borrer’s Male-fern *Dryopteris borreri*

Signs of Life

Fast forward to early winter and most of our ferns have now begun transitioning into their sporophyte generation. Some, such as Beech Fern and the larger Dryopteris species, are lagging behind, with only the tiniest hint of their first fronds visible. Others are positively romping away, particularly Brittle Bladder-fern which has already warranted the relocation of larger plants to individual pots (again in sealed containers) for growing on over winter. I have also been impressed with Soft Shield-fern.

As we now have so many young ferns growing in containers, we have broken with the usual advice that recommends leaving sporlings in place until they are large enough to handle. Instead, we have opted to split our batches, leaving some in situ while moving small clumps of prothalli to individual containers to see whether this results in healthier, more vigorous plants. All are being kept under plastic to retain that all-important humidity, but I have already begun removing the lids from larger specimens to gradually accustom them to harsher conditions, with the aim of moving some outdoors come spring.

The images below show various species as of 20 November 2026, which is not bad at all for spores sown in June and July.

Young Brittle Bladder-ferns *Cystopteris fragilis* potted up in Novemeber 2025 (sown in June)

Transplanted Maidenhair Spleenwort *Asplenium trichomanes* with signs of new growth

A Few Problems

While some of our ferns have been successful, others have failed miserably, and in most cases, this is entirely my fault. I mentioned earlier that you should ignore your spores for a prolonged period, something I confess I didn’t do, as too often I found myself opening the pots for a sneaky look. Doing this, it seems I allowed contaminants into the pots, resulting in mould that quickly overtook many of the young plants. We lost most of our Rustyback specimens this way, but I did discover that you can safely move prothalli to another jar, helping to preserve at least some plants.

Not sterilising the soil sufficiently may also have been a problem, as algae and bryophytes appeared in several pots, leading to competition with the young ferns. The greatest problem of all, however, seems to be overcrowding. It is all too easy to sow far too many spores in a single container, and when this happens, the added competition prevents the prothalli from developing properly. This is currently affecting our Dryopteris affinis containers, but I hope it can be remedied by thinning, just as you would with the seedlings of any other plant.

And with that, the first stage of the challenge is complete. I will post an update further down the line as we progress to potting on and eventually planting out. I am optimistic, as the whole process has been far easier and, dare I say it, quicker than I envisaged at the start. If you have ever fancied growing ferns from spores yourself, I would strongly recommend giving it a go. You may find it slightly addictive and end up with more than you can handle, just as we have.

As a quick further update since drafting this post, we ended up sowing spores from a range of other cultivated species, including Oak Fern Gymnocarpium dryopteris and Limestone Fern Gymnocarpium robertianum, as well as some Narrow Male-fern Dryopteris cambrensis gathered from an unassuming Northumbrian roadside. Being more ambitious, I am also attempting to hybridise Male-fern Dryopteris filix-mas with Borrer’s Male-fern to create Cryopteris × critica, but we will see how that pans out.

Botany along the Bizzle Burn

Northumberland’s Cheviot Hills have been a major focus of my extracurricular botany outings so far this year. Back in May, we enjoyed a fantastic visit to the Hen Hole and later returned with a group from the Natural History Society of Northumbria for another day of hills, ferns, and mountain flowers. Fast forward a few weeks, and it was time for another trip—this time to a part of the area I’m less familiar with.

The Bizzle Burn is a small waterway that flows down from Bizzle Crags toward Dunsdale in the College Valley. It’s a steep walk, but one that offers plenty for the keen-eyed botanist. The site has drawn attention for centuries due to its rare arctic-alpine flora, interesting ferns, and other botanical gems. This was our second attempt to explore it, having been rained off the hill late last year.

Spoiler – due to an unfortunate phone malfunction, pictures from this trip are somewhat limited. Sadly this included some of the special plants seen during the day. Still, we’ll preserve.

Setting out from our starting point at Cuddystone Hall, the walk to the base of the hill proved highly interesting. Along the path, typical upland grassland species such as Fairy Flax Linum catharticum, Wavy Hair-grass Avenella flexuosa and Wild Thyme Thymus drucei were seen. These are all plants commonly associated with the thin, parched soils of this terrain. On the walls surrounding a farmhouse passed early in the walk, the day’s first ferns made an appearance in the form of Maidenhair Spleenwort Asplenium trichomanes subsp. quadrivalens and Wall-rue Asplenium ruta-muraria. The Harebells Campanula rotundifolia were also particularly striking along this stretch.

Slightly more unusual species were encountered in a damp rut about halfway along the trail. The vivid flowers of Bog Asphodel Narthecium ossifragum were an immediate draw, and a closer inspection revealed the characteristic leaves of Round-leaved Sundew Drosera rotundifolia, one of our region’s few carnivorous plants.

Further uphill, a pause to explore the scree slopes yielded a fascinating suite of ferns. The most plentiful was Narrow Male-fern Dryopteris cambrensis, easily recognised by its distinctive wavy pinnae but also recorded were Male-fern Dryopteris filix-mas and several young specimens of the quirky Parsley Fern Cryptogramma crispa. A bit of poking around beneath overhangs revealed both Brittle Bladder-fern Cystopteris fragilis and Polypody Polypodium vulgare.

At the bridge at the foot of the trail leading up the Bizzle, another overhang held a somewhat desiccated example of what I believe to be Delicate Maidenhair Spleenwort Asplenium trichomanes subsp. trichomanes — a relatively rare relative of the more familiar Maidenhair Spleenwort commonly found on garden walls. A few Common Spotted-orchids Dactylorhiza fuchsii were also growing nearby, and a look at the riverside gravels revealed an interesting variety of willows. These included Purple Willow Salix purpurea, Osier Salix viminalis, Goat Willow Salix caprea, Eared Willow Salix aurita, and Grey Willow Salix cinerea.

Delicate Maidenhair Spleenwort
*Asplenium trichomanes subsp. trichomanes*

Having passed the last vestiges of civilisation, we soon began our walk up the burn, initially passing through heather and areas of acid grassland before following the now stone-dry watercourse the rest of the way. It was tough going in places, and a near miss with a large female Adder certainly livened up proceedings. A few Common Lizards were also spotted along this stretch.

It was around this point that my camera began to malfunction, so photographic evidence is limited. Nevertheless, the plant life in the burn bed was typical for this part of the valley. The montane willowherbs were in full flower, with some attractive examples of Chickweed Willowherb Epilobium alsinifolium found alongside Alpine Willowherb Epilobium anagallidifolium and the non-native New Zealand Willowherb Epilobium brunnescens. Also of note was a lingering patch of Pale Forget-me-not Myosotis stolonifera, another local speciality. A suite of species more commonly associated with woodland was also encountered, including Opposite-leaved Golden Saxifrage Chrysosplenium oppositifolium, Wood Crane’s-bill Geranium sylvaticum, and Wood Sorrel Oxalis acetosella.

Chickweed Willowherb *Epilobium alsinifolium*

Befitting my newfound obsession with ferns, it was the pteridophytes that proved most interesting at these lofty heights. The day’s target species, Northern Buckler-fern Dryopteris expansa, was eventually located after considerable effort tucked among its preferred scree habitat. The diversity of other species present was impressive as well and, in no particular order, included common types such as Broad Buckler-fern Dryopteris dilatata, Narrow Male-fern Dryopteris cambrensis and Hard-fern Blechnum spicant, along with some altogether scarcer finds: Oak-fern Gymnocarpium dryopteris, Parsley Fern Cryptogramma crispa, and Borrer’s Male-fern Dryopteris borreri. The latter was a bit of a surprise, as I’ve always associated it with woodland – but who knows!

At the top of the burn, we eventually emerged into a vast, open corrie at the foot of Bizzle Crags. This is where many of the more interesting plants are known to grow, though oddly, we struggled to locate several of the anticipated targets – including Alpine Clubmoss and Fir Clubmoss – and some others were well past their best due to the heat, particularly the Mossy Saxifrage.

That said, Beech Fern Phegopteris connectilis was a pleasing find among the scree, and a scramble up to a damp ledge yielded some interesting discoveries, including Butterwort Pinguicula vulgaris and Viviparous Sheep’s-fescue Festuca vivipara. I had considered continuing higher, but by this point, my legs were beginning to protest. The 1970s record of Green Spleenwort will have to wait for another day…

Viviparous Sheep’s-fescue
*Festuca vivipara*

We ended our hike at the corrie, opting not to follow the burn further on this occasion. A walk beyond that point will have to be saved for a cooler day, I think. Still, the descent via a slightly different route added plenty to the plant list and offered some truly stunning views.

In my opinion, this walk isn’t quite as botanically diverse as the Hen Hole, but it’s a beautiful route nonetheless and well worth doing if you find yourself with a day to spare.

Fern of the Week: Beech Fern

For our next plant profile, we’ll take a closer look at one of my favourite ferns – the delicate and beautiful Beech Fern Phegopteris connectilis. This is a rather uncommon species in the North East but one which I have been encountering more frequently thanks to my ongoing Big Fern Challenge. Now seemed like a good time for a closer look.

Beech Fern

Phegopteris connectilis

Beech Fern is not a species many of us will encounter regularly – unless you’re lucky enough to live in parts of Scotland or perhaps Wales.

This delicate and attractive fern tends to grow in special habitats, including ancient woodlands dominated by Sessile Oak and on shaded, humid gully sides where base-rich water seeps through. Locally, I have found it in both habitats, though the greatest concentrations are nestled among boulder scree in upland areas or tucked away in permanently damp, humid spots around waterfalls and burns. Beech Fern is known to be intolerant of grazing and is therefore often found in places out of reach of passing sheep or deer.

Surprisingly, it is seldom found under Beech trees as it avoids overly acidic substrates, favouring instead neutral to mildly acidic.

Beech Fern *Phegopteris connectilis* spotted at Hen Hole in the Cheviots

Upon further reading, I discovered that Beech Fern has a rather interesting history. It was first reported by Bobart as far back as 1699, who – using typically lengthy Latin – named it Filix minor Britannica pelliculo pallidore alis inferioribus deorsum spectantius. Quite a mouthful, but the name roughly translates to “a small British fern with pale green fronds and downward-pointing pinnae.” Even today, this description remains remarkably accurate!

The name Phegopteris connectilis is a combination of Greek and Latin terms. Phegopteris comes from the Greek words phegos meaning “Beech” and pteris meaning “fern”, describing a fern associated with beech trees. The specific epithet connectilis is Latin and translates “fastened together”.

Although uncommon in lowland areas, the distribution of Beech Fern is considered stable by the BSBI, with new sites being discovered on the edges of its Scottish and Welsh populations. While it may have declined slightly in England, it can still be found in most of its historic haunts.

Unfurling Beech Fern *Phegopteris connectilis* spotted at Hen Hole in the Cheviots

In terms of its associates, Beech Fern commonly grows alongside Oak Fern Gymnocarpium dryopteris in ancient woodland but in the uplands, may often be found alongside Brittle Bladder-fern Cystopteris fragilis on damp ledges, and in scree alongside Mountain Male-fern Dryopteris oreades.

Identification

Phegopteris connectilis is an easy plant to identify. It is a small, rhizomatous species that can form dense, spreading colonies in suitable habitats. Telling it apart from other ferns shouldn’t be a problem if you focus on a few key features.

Firstly, unlike any other British fern, the pinnae are winged – meaning they’re connected to the rachis along their entire length. This is the origin of the specific epithet connectilis.

Secondly, take a close look at the lowest pair of pinnae. These are opposite, backward-facing, and angled at about 90° to each other. They typically stand erect – resembling a pair of rabbit ears!

That’s all there is to it with this one.

Beech Fern *Phegopteris connectilis* at Hareshaw Linn, Northumberland

Distribution

In the North East, Beech Fern is an uncommon species. As the orange dots indicate, it hasn’t been recorded at many of its historic sites since the turn of the millennium.

Nevertheless, the species persists in several locations, with notable clusters in the Kielder and Cheviot areas of Northumberland, as well as in the North Pennines of County Durham. It can also be found along watercourses and in remnants of ancient woodland along the River Tyne, from Haltwhistle to Hexham.

Given the lack of recent records, it seems reasonable to conclude that Beech Fern has been lost from most lowland areas of the region.

*Phegopteris connectilis* in the The ferns of Great Britain and Ireland (Plate IV)

On the hunt for Dryopteris lacunosa

Last week, I visited an abandoned quarry in Upper Teesdale and found myself puzzling over an unusual-looking fern. It seemed to resemble both Borrer’s Male-fern Dryopteris borreri and the Common Male-fern Dryopteris filix-mas, but something didn’t feel quite right – at least to my novice eyes.

The main point of confusion was the distinctive ‘dark spot’ at the base of the costa which typically helps identify the scaly male-ferns. In this specimen, the spot was unusually extensive and, on the underside of the pinna, extended some way up the costa. From my hazy recollection, in D. borreri, this spot is usually fairly faint and confined to the point where the pinna meets the rachis.

Beyond that, I was stumped. Aside from snapping the photos below, I decided to leave it there. However, having revisited a few Facebook posts from local botanist, John Durkin, mentioning that same feature in another species, Alpine Male-fern Dryopteris lacunosa, I am beginning to wonder…

Unknown *Dryopteris* from Upper Teesdale

After a deep dive on the internet, I found relatively little information about Dryopteris lacunosa. It appears to be a fairly recent split from the Dryopteris affinis aggregate and has only recently started to be recorded in parts of the UK. From what I can gather, most records are concentrated in Cumbria, western Scotland, Wales, and southern Ireland. Pleasingly, however, the species has now been recorded at a few select sites in North East England – thanks to the efforts of recorders far more knowledgeable than I.

One of these sites, Blaydon Burn, lies just a short distance from home so with a day off work, I thought I’d try to seek it out for myself.

Dryopteris lacunosa at Blaydon

The most helpful information I’ve found on Dryopteris lacunosa comes from an excellent page by Roger Golding, which includes images highlighting the key features to look out for – most notably, that extended dark blotch on the costa. A very informative online talk by Alison Evans offers further insight, mentioning additional traits such as the distinctive double teeth, funnel-shaped gaps between the teeth, and the long stalks on the pinnae. A third mention, on a blog by the Kirkcudbrightshire Botany Group, echoed many of these points. All of it made for very useful reading on the bus to Blaydon!

Blaydon Burn Nature Reserve was entirely new to me, but with its steep, well-vegetated banks lining the burn, it immediately looked promising for ferns. And indeed, it delivered with plenty of Male-fern, Borrer’s Male-fern, and Broad Buckler-fern Dryopteris dilatata noted, along with Hard-fern Blechnum spicant, Lady-fern Athyrium filix-femina, and Hard Shield-fern Polystichum aculeatum. All species one can expect to encounter in Tyneside’s humid denes.

The first interesting fern (pictured below) came about 15-minutes into the walk…

Possible *Dryopteris lacunosa* showing extensive dark spot

In the individual pictured above, the dark mark at the junction of the costa and rachis was extremely pronounced extending, in some cases, a good inch up the stem. In this neck of the woods, that would suggest either D. borreri or D. lacunosa (it certainly wasn’t D. affinis). If you look closely at the zoomed-in image below, you can also make out double teeth on the auricles (the ‘ear’ or lobe at the base of the pinnule). These were distinctive in some cases but rather variable, and certainly not present on all of the lowest pinnules I examined.

The gaps between the teeth were even less clear-cut, and I must admit this isn’t an area I’m particularly familiar with. That said, in many instances, they could reasonably be described as funnel-shaped, though I do rather like the ‘fjord-shaped’ description mentioned in the video linked above.

After pottering further into the woods, I came across two more promising individuals on a slope among patches of both D. filix-mas and D. borreri. In these specimens, the dark marking was even more extensive and far more convincing. The pinnae stalks also appeared longer, and at least some double teeth were clearly visible. I still can’t quite wrap my head around the reference to ‘islands’ in this resource, but otherwise, the features seemed to line up well.

The fourth and final candidate I found was a small, immature specimen perched above an eroded area further up the bank. Most of its fronds had yet to develop the characteristic dark mark, but on one mature frond, the blotch was incredibly extensive – more so than I’ve seen on any fern before. This feature alone was more convincing than the presence of double teeth, though the auricles on the more mature frond were clearly toothed as well.

Having spent a good few hours now examining collected fronds and poring over photos from the trip, I feel reasonably confident that I’ve found something different from the ferns I usually encounter. After comparing my specimens to images associated with accepted records of Dryopteris lacunosa in the local area, I’m cautiously optimistic that this may, in fact, be it. That said, I wouldn’t be at all surprised if I’m mistaken – ferns are a notoriously tricky group, and despite the time I’ve been dedicating to learning them, they continue to frustrate me no end. If, by chance, a proper pteridologist stumbles across this post, please do feel free to correct me!

As for my original Teesdale fern – the jury is still out. The dark spot is certainly promising, but the absence of double teeth (or lobes, for that matter, as seen in Roger Golding’s images) is a bit disconcerting. I won’t be submitting a record for that one unless someone with more expertise can weigh in and help clarify things.

Along the Hareshaw Burn

I love Hareshaw Linn, so much so have that I have written about the plants there several times on this blog (see here and here). There is just something about remote but lovely dene, with its ancient woodland flora and impressive waterwall that makes me incredibly happy. Despite frequent visits, each time I travel there I manage to see something new and worth talking about so, despite a little repetition, here we are again!

Last weekend, Matt and I had run out of ideas for new places to visit in the local area, so with ferns in mind, we decided to return to our favourite local haunt for a walk along the Hareshaw Burn. Setting out from Bellingham, the walk into the dene was fairly uneventful, apart from the appearance of Downy Currant Ribes spicatum in scrub near the car park and an impressive patch of Good-King-Henry Blitum bonus-henricus in grassland about 100 metres into the walk. Both are elusive plants in the area.

Reaching the dene, we were immediately greeted by a burst of colour from countless woodland flowers, a welcome change given our tendency to visit later in summer, when most of the blooms have faded. The bluebells and anemones had long since passed, but in their place we found plenty of Sanicle Sanicula europaea, along with Wood Crane’s-bill Geranium sylvaticum and Water Avens Geum rivale. Slightly more interesting was the presence of several patches of Hybrid Avens Geum × intermedium, distinguishable by its yellow colouring inherited from its other parent, Wood Avens Geum urbanum.

**Wood Crane’s-bill**
*Geranium sylvaticum*

A little further into the dene, these relatively common woodland flowers faded into insignificance with the discovery of perhaps the day’s most exciting find: Herb-paris Paris quadrifolia. This rare and rather special plant typically grows only in the high quality woodlands and it is a joy to behold under any circumstances. I seem to be on a lucky streak with this species, having already encountered it this year at Letah Woods and Morpeth. However, while I knew it existed somewhere in the area, the Hareshaw population was entirely new to me. We came across a great many plants scattered across an area of about five metres, though realistically there could have been many more.

Prying ourselves away from the Paris, the next portion of the walk brought a few other interesting woodland plants. Common Cow-wheat Melampyrum pratense was a particularly nice find, and a species I rarely encounter, and plenty of Yellow Pimpernel Lysimachia nemorum was also seen along the path edges.

The grasses too were well worth a look with several ancient woodland indicators found in good quantity. By far the most abundant was False Brome Brachypodium sylvaticum, but we also noted Hairy-brome (Bromopsis ramosa), Wood Melick Melica uniflora and Giant Fescue Schedonorus giganteus. The most interesting grass, however, was Wood Fescue Drymochloa sylvatica. This rare species is limited in distribution to just a few parts of the UK, where it grows on near-vertical cliffs, rocky slopes and beside waterfalls. Northumberland supports one of the largest populations, with a strong concentration of sites along the River Tyne.

But what about the ferns? The steep-sided banks of the Hareshaw Burn and Hareshaw Linn are notable for supporting a range of uncommon – and in some cases, extremely rare – ferns. As we wandered along, we spotted many of the more commonplace species with relative ease, including Broad Buckler-fern Dryopteris dilatata, Lady-fern Athyrium filix-femina, Borrer’s Male-fern Dryopteris borreri and Male-fern Dryopteris filix-mas.

Much more exciting, however, was the presence of two rather uncommon ferns typically associated with shaded, humid woodlands like this: Beech Fern Phegopteris connectilis and Oak Fern Gymnocarpium dryopteris. Both are found predominantly in upland areas and tend to grow in moist, undisturbed settings, often on steep banks. Beech Fern in particular is a striking plant, easily recognised by its erect and distinctive ‘rabbit ear’ leaflets, which set it apart from all other species.

Also of note on the fern front was a small buckler-fern found on a steep bank beside the path. On closer inspection, it turned out to be Narrow Buckler-fern Dryopteris carthusiana – a species I must admit to having overlooked on all my previous visits to the site. It can be distinguished from the larger and more abundant Broad Buckler-fern by its uniformly pale scales and its rhizomatous habit, with fronds pointing in separate directions. This contrasts with the typical shuttlecock appearance of the latter species.

We also recorded Hard Shield-fern Polystichum aculeatum along this stretch, but failed to find the hoped-for Lemon-scented Fern Oreopteris limbosperma.

**Narrow Buckler-fern** *Dryopteris carthusiana*

Eventually, we reached the picturesque waterfall at Hareshaw Linn and after a spot of lunch, set about exploring the ferns growing on the steep limestone cliffs nearby. The rarest fern on site turned out to be the easiest to find, with hundreds of specimens of Lobed Maidenhair Spleenwort Asplenium trichomanes subsp. pachyrachis spotted during our short visit. I’ve written about this attractive little fern before, but suffice it to say that Hareshaw Linn is the only place in Northumberland where this subspecies can be seen.

Also present on the falls, though far rarer, was Green Spleenwort Asplenium viride – seen clinging to the cliff face. This species appears to be just barely hanging on here. Brittle Bladder-fern Cystopteris fragilis was thankfully more widespread and added a final touch of interest before we turned for home.

**Lobed Maidenhair Spleenwort** *Asplenium trichomanes* subsp. *pachyrachis*

An expedition to Falcon Clints

Upper Teesdale is a truly remarkable place, packed with rare and wonderful arctic-alpine plants. Each year, I try to visit at least once and each time manage to discover something new and exciting to make the trip worthwhile. Last week, my annual visit came around again and together with NHSN’s Urban Naturalist, Ellie, I set off in search of a group of species I’d yet to properly explore in this part of the world – ferns!

Of course, before the fern hunting could begin, we had to reach Falcon Clints, a truly stunning gorge nestled below the confluence of Maizebeck and the River Tees. To get there, we first had to cross Cow Green with all its botanical riches (such a chore, I know!). As expected, this leg of the trip was a delight with hundreds of Mountain Pansies Viola lutea now in full bloom. As you can see, these cheerful little plants come in a brilliant range of colours.

Despite the abundance of pansies, one thing that struck us immediately was the near-total absence of Spring Gentians Gentiana verna. They had all gone over, perhaps hastened by the warm weather. Nevermind; what we did find during this stage of the walk more than made up for it. In damper spots, the Bird’s-eye Primroses Primula farinosa were out in force Variegated Horsetail was a particularly nice find in the flushes. Hardly the most inspiring plant, I confess, but I’ve always had a soft spot for it.

Variegated Horsetail *Equisetum variegatum*

Further down the trail, about halfway to Cauldron Snout, more notable species were found. Mountain Everlasting Antennaria dioica was a highlight, and Sea Plantain Plantago maritima was in flower. In the drier, more exposed areas of sugar limestone, we also came across Spring Sandwort Sabulina verna, and grassy patches offered Lesser Clubmoss Selaginella selaginoides, Blue Moor-grass Sesleria caerulea, and countless sedges which we opted to overlook this time.

The initial descent down Cauldron Snout is truly beautiful and well worth a pause, if you’re ever passing. Falcon Clints is equally, if not more, breath-taking with its steep dolerite cliffs fringed by dramatic scree slopes. It’s worth taking a moment to appreciate the gradual shift in vegetation as you scan down the cliff face: moorland heather giving way to stunted trees and herbs, and eventually, to ferns. We even spotted a few Ring Ouzel – always nice to see.

The list of ferns found at Falcon Clints is impressive – if a little daunting – with species ranging from common woodland fare to truly rare plants found pretty much nowhere else in England. Some of the more familiar species we encountered early on included Lady-fern Athyrium filix-femina, Bracken Pteridium aquilinum, Narrow Male-fern Dryopteris cambrensis, Broad Buckler-fern Dryopteris dilatata and Hard-fern Blechnum spicant, but these quickly faded into the background as we began to explore the scree.

The first exciting discovery was the curious-looking Parsley Fern Cryptogramma crispa, a calcifuge pioneer often found on exposed rock and former mine waste. It is a rather lovely plant, as is the next species we came across – Beech Fern Phegopteris connectilis. Now that I think about it, this may be the first time I’ve seen this distinctive little fern outside of damp, humid woodland.

Arguably more exciting, at least for this novice pteridologist, was the presence of several stands of Mountain Male-fern Dryopteris oreades. Though similar in appearance to the ubiquitous Male-fern Dryopteris filix-mas that many of us see regularly, this species is far more particular about where it grows and favours upland slopes and boulder fields. It can be distinguished from its commoner relative by the underside of its fronds where the sori are confined to the lowest portion of the pinnule. If you spot distinctive clumps of ferns adorning a mountainside, it’s well worth taking a closer look.

As we meandered through the valley, it was hard not to be distracted by the trees. Though relatively sparse at Falcon Clints, the ones that do grow here are gnarled, twisted, and strikingly beautiful. Juniper Juniperus communis is easy to find, as are Aspen Populus tremula and Rowan Sorbus aucuparia. Perhaps more intriguing though are the birches and it is worth checking any with noticeably contorted trunks and branches for signs of the upland subspecies of Downy Birch, Betula pubescens subsp. tortuosa. We spotted one along the way though admittedly, we weren’t looking that hard.

While most of Falcon Clints is dry and exposed, there are pockets of deep shade — particularly beneath rocky overhangs. It was in these secluded spots that we searched for our next group of ferns, and before long we were rewarded with some healthy specimens of Green Spleenwort Asplenium viride, a species abundant in this part of the world but rather rare elsewhere. Growing alongside it were Brittle Bladder-fern Cystopteris fragilis and Maidenhair Spleenwort Asplenium trichomanes subsp. quadrivalens. The latter prompted a closer look just in case it turned out to be something rarer but alas, I think not. We also found a solitary Hard Shield-fern Polystichum aculeatum – a common species, yet the only one we encountered all day.

We paused for lunch and eventually decided to turn back roughly 1.5 miles into the valley, right at the point where the path disappears and you have to scramble over rocks to go any further (you’ll know it when you see it). During our break, we took the opportunity to explore a particularly diverse overhang that held more than a few interesting plants. Beneath some willows which we tentatively identified as Dark-leaved Willow Salix myrsinifolia, we found Bird’s-eye Primrose, Marsh Valerian Valeriana dioica, Butterwort Pinguicula vulgaris, and some fine examples of Northern Bedstraw Galium boreale, not yet in flower.

After that, all that remained was to head back the way we came, admittedly rather slowly so to spend as much time as possible in this incredible place. However, there were a few more discoveries to share…

At the start of this post, I mentioned that Falcon Clints is home to some incredibly rare and special ferns. One in particular stands out: Holly-fern Polystichum lonchitis.

This striking fern prefers well-drained, cool and moist conditions at the base of cliffs, typically in stabilised boulder scree. A poor competitor, it avoids densely vegetated areas and is considered vulnerable across much of its native range. It wasn’t a species I had seen before, so you can imagine my delight when, after scrambling up a particularly steep bank, we were rewarded with the specimen shown below. A real thrill, even if it did look a little weather-beaten.

I won’t share precise location details here, but the information is out there if you know where to look.

The Urban Ferns of Newcastle and North Tyneside

While recording for the Urban Flora, I’ve now encountered a total of 23 fern species growing in a wild or naturalised state within the conurbation. An additional three species have been submitted by fellow recorders, bringing the total to a healthy 26. This is quite an impressive number given the area covered, though it still represents a relatively small 2.3% of the total plant species recorded from the area.

Nonetheless, urban ferns are an interesting bunch. In the style of my previous posts [here] and [here], I thought I’d explore them properly on this blog — partly for reference, and partly in the hope that someone, somewhere, finds these rambles either useful or at least somewhat interesting.

Before I go any further, however, a very big thank you to Chris Barlow and David Jarema for making their photography available for projects such as this. It is most appreciated.

Common Ferns

The Big Five

The “big five” urban ferns represent the most common and widespread species within the conurbation. All are fairly familiar and either thrive in a wide variety of habitats or are associated with environments so ubiquitous that they’ve become an almost daily sight.

Chief among them is the Male Fern Dryopteris filix-mas, which has so far been recorded in 135 squares—an impressive 71% of those surveyed. It’s truly a fern that gets everywhere: from woodlands and hedgerows to urban walls, gutters, gardens, and even pavements close to overflowing drainpipes. While I doubt it will turn out to be truly ubiquitous across every square, it’s about as close as a fern can reasonably get.

Not far behind in the numbers game is Hart’s-tongue Asplenium scolopendrium, an evergreen fern of moist, shaded woodlands that is also frequently encountered on mortared walls and masonry. Recorded from 102 squares (53%), it’s certainly abundant.

Hart’s-tongue *Asplenium scolopendrium* © Chris Barlow

Two other “wall ferns” are also doing well: Wall-rue Asplenium ruta-muraria, noted in 84 squares (44%), and Maidenhair Spleenwort Asplenium trichomanes, in 70 squares (36%). While marginally less widespread, both can be prolific where they occur – typically in older, more unkempt terraced neighbourhoods, where less rigorous weeding allows them to thrive. In contrast, they can be surprisingly scarce in modern developments or more affluent areas where tidiness tends to take priority.

The final fern worthy of inclusion in this section is Broad Buckler-fern Dryopteris dilatata. Typically a species of somewhat acidic, damp soils, it’s most often encountered in woodland settings. However, it has proven far more catholic in its habitat preferences than many other woodland ferns, turning up readily in newer woodlands, plantations, hedgerows, rail embankments, and even grassy habitats on occasion. So far, it has been recorded in 48 (25%) survey squares.

Wall-rue *Asplenium ruta-muraria* © Chris Barlow

Localised Ferns

The next group of ferns are altogether more particular in their habitat preferences and occur much more sparingly across the conurbation — though not quite so sparsely as to be considered rare. With the exception of one notable species, all are best described as woodland ferns within Newcastle and North Tyneside. We’ll look at these first.

Hard Shield-fern Polystichum aculeatum and Soft Shield-fern Polystichum setiferum make for an interesting duo. The former is native to the area, typically inhabiting damp, shaded stream-sides and rocky ledges within woodland. The latter, meanwhile, is a more recent arrival, introduced occasionally but now subject to natural colonisation as well. Intriguingly, the two species are neck-and-neck in terms of occurrence, each recorded from 10 survey squares (5%). Both remain closely tied to the relic semi-natural woodland of Newcastle’s denes, though Soft Shield-fern has begun to spread a little more widely.

Hard Shield-fern *Polystichum aculeatum*
© James Common

Another interesting pair are the Scaly Male-ferns. Within the conurbation, we seem to host two fairly frequent species and one rarer one (which I’ll cover later). Among the more commonly encountered are Borrer’s Male-fern Dryopteris borreri and Golden-scaly Male-fern Dryopteris affinis.

Of the two, D. borreri is notably more abundant, recorded in 26 survey squares 13.7%. While it tends to favour older woodland habitats, it also turns up elsewhere including newer plantations. D. affinis, on the other hand, is much more selective, preferring damp locations in older woodlands, and has been recorded in just 7 squares 3.7%. In fact, the only places I’ve found it in any real abundance are Jesmond and Wallbottle Denes, now that I think about it.

The conurbation’s wooded denes are also just about the only places where you’re likely to encounter Hard Fern Blechnum spicant these days. Recorded in 8 survey squares 4.2%, it is largely restricted to Sugley, Walbottle, Jesmond, and Denton Denes – with the only notable outlier being a small population at Gosforth Nature Reserve where the acid soils suit it well.

Hard Fern *Blechnum spicant* © James Common

Distribution of Hard Fern *Blechnum spicant* within Newcastle & North Tyneside

Two more uncommon species associated with the conurbation’s woodlands – albeit with a bit more flexibility – are Lady-fern Athyrium filix-femina and Bracken Pteridium aquilinum.

Lady-fern, recorded from 21 squares (11.1%), remains fairly localised, with the best populations once again found within the area’s wooded denes. However, it will readily colonise other damp, shaded spots such as ditches, hedgebanks, and more recent plantations.

Bracken, by contrast, is quite the opposite. It favours somewhat acidic soils in the drier, upper reaches of older woodlands, where it can be particularly abundant. Still, it’s far from confined to such settings and occurs more broadly across the conurbation as a colonist of all sorts of habitats, especially rail sidings and grassy banks. In total, Bracken has been observed in 29 squares (24%), though it is by no means “common”.

Lady-fern *Athyrium filix-femina* © Chris Barlow

The final species worthy of mention at this stage is, rather refreshingly, not a fern of woodlands but instead a calcicole, favouring mortared walls in urban areas. Black Spleenwort Asplenium adiantum-nigrum has been recorded from 28 squares (14.7%) so far. While one of the less common wall ferns overall, it can be surprisingly plentiful in certain neighbourhoods, particularly around Walker, Heaton, and Wallsend. It also occurs sporadically in squares around Newcastle City Centre, including in spots where even more typical ferns like Wall-rue are absent.

Black Spleenwort *Asplenium adiantum-nigrum* © Chris Barlow

Distribution of Black Spleenwort *Asplenium adiantum-nigrum* within Newcastle & North Tyneside

Rare and Scarce Ferns

And so we come to the conurbation’s rare ferns – the ones that truly generate excitement when you stumble across them. There’s a surprising number of these, though they all tend to fall into two distinct categories: rare natives or exotic introductions. We’ll start by looking at the native species first…

Scarce Native Species

Kicking off our collection of rare woodland ferns is a duo found exclusively at Gosforth Nature Reserve —suggesting a preference for mildly acidic conditions.

Narrow Buckler-fern Dryopteris carthusiana has long been a rarity in the conurbation, with no local records since George Swan encountered it in the Gosforth Park back in the 1970s. That changed recently when local botanist, John Durkin, rediscovered it in wet woodland and relic acid grassland at the reserve. Found in just 1 square (0.5%), it is by all accounts a true local rarity. The same goes for its hybrid with Broad Buckler-fern, Dryopteris x deweveri, also noted from a single square (0.5%) during surveys by the same recorder.

Speaking of hybrids, Polystichum × bicknellii — the cross between Hard Shield-fern and Soft Shield-fern —has so far only been recorded from Jesmond Dene, where both parent species occur. Meanwhile, Gosforth Nature Reserve has produced two further exciting finds: Narrow Male-fern Dryopteris cambrensis and Lemon-scented Fern Oreopteris limbosperma, each recorded from just one square (0.5%). Both are, for now, exceptionally scarce within the conurbation.

Lemon-scented Fern *Oreopteris limbosperma* © James Common

Rustyback Asplenium ceterach has long been a rare fern on Tyneside. For years, it was known only from an exterior garden wall in North Shields where happily, it still persists today. Encouragingly, it was also recorded last year on an exterior wall in Brunswick, where it was growing in mortar alongside a mix of more familiar species. So far, Rustyback has been observed in just 2 squares (1.1%).

And since we’re on the subject of walls, now seems a fitting moment to turn our attention to the urban Polypodium species. Both Polypody Polypodium vulgare and Intermediate Polypody Polypodium interjectum are rare within the conurbation — though they may well be under-recorded.

P. vulgare has proven the more widespread of the two, typically occurring as a thinly distributed epiphyte of older woodlands, with records from Jesmond, Sugley, and Denton Denes. It also occasionally turns up on old walls, though here it remains quite scarce. To date, it has been recorded from 9 squares (4.7%). In contrast, P. interjectum is more characteristic of mortared walls and has been noted as a scattered colonist in 3 squares (1.6%).

Rustyback *Asplenium ceterach* © James Common

A final rare native worthy of mention is the unusual Adder’s-tongue Ophioglossum vulgatum, a species typically found in higher-quality, neutral to acidic grasslands. Within the conurbation, it appears to be in decline – likely as aa consequence of poor grassland management in many areas. So far, it has been observed from just two well-known sites: a verge along Salter’s Lane and, in greater numbers, from grassland near Havannah Nature Reserve. It remains restricted to 2 squares (1.1%).

Adder’s-tongue *Ophioglossum vulgatum* © Chris Barlow

Some Exotic Ferns

As I’ve touched on in previous posts, Jesmond Dene is home to its fair share of weird and wonderful exotic plants, including several ferns. Most of these have been encountered near the remnants of a derelict Victorian fernery, and it’s hard to say whether they’ve persisted here for decades or are the result of more recent introductions. Either way, three exotic species now appear to be growing wild in the Dene: Japanese Shield-fern Polystichum polyblepharum, Japanese Buckler-fern Dryopteris erythrosora, and Western Sword-fern Polystichum munitum, each recorded from a single square (0.5%).

A fourth species, House Holly-fern Cyrtomium falcatum is not found in the dene but instead, has been noted from the base of a sunny garden wall in Gosforth – clearly having spread from planted stock nearby.

And really, who doesn’t enjoy a touch of the exotic while botanising the big city?

House Holly-fern *Cyrtomium falcatum*
© James Common

And there we have it, a not-so-concise tour of the urban ferns recorded as part of the project so far. There’s a surprising number out there waiting to be discovered. With the conurbation’s woodlands now fairly thoroughly surveyed, I suspect the distributions of many woodland species will remain relatively stable by the time the project wraps up. That said, we may well see an uptick in species colonising walls and masonry, particularly as urban habitats are surveyed in more depth.

I can’t imagine there are too many more species left to uncover but given the exotics mentioned above, you never really know what might be lurking just around the corner, do you? Good job there are some handy resources out there…

Frustrating Ferns at Hareshaw Linn

I must confess that although I have been botanising for some time now, ferns have proven a difficult group to master. Indeed, master is probably the wrong word as despite countless trips in search of the species found across North East England, I am still but a novice. Or perhaps an improver!

Despite the difficulties associated with telling many of them apart, August is a great month to look closer at ferns and last week, I decided it was high time I bit the bullet and factored them into the programme of ‘Botanists Year’ trips I am currently leading for the Natural History Society. Knowing the perfect place, with 10 botanists in toe, we decided on a visit to the pteridologist’s paradise that is Hareshaw Linn in Northumberland.

Starting out, a variety of common and widespread ferns were easy to find as we made our way into the wooded valley. Broad Buckler-fern (Dryopteris dilatata), Bracken (Pteridium aquilinum) and Male-fern (Dryopteris filix-mas) came first, followed by the distinctive Hard-fern (Blechnum spicant) and later, some rather nice stands of Polypody (Polypodium vulgare). Upon scrutiny when I returned home, these were confirmed to the be common sort.

In the initial stages of our walk at Hareshaw Linn, several other interesting plants were noted too including Wood Melick (Melica uniflora), Giant Fescue (Schedonorus giganteus) and a sizeable patch of Good-king-henry (Blitum bonus-henricus) but ferns soon rose to the fore once more with new additions in Lady-fern (Athyrium filix-femina), with it’s lovely j-shaped sori, and the first of the day’s scaly male-ferns. After a closer look, this was revealed to be Golden-scaled Male-fern (Dryopteris affinis) on account of the rounded, toothed lower pinnule.

In my experience, most of the scaly male-ferns I check near Newcastle turn out to be Borrer’s Male-fern (Dryopteris borreri) but this did not appear to be the case at Hareshaw. Indeed, checking dozens of ferns along the initial leg of our walk, almost all proved to be affinis. We did, however, find a nice example of Borrer’s Male-fern a little further into the Linn, spending some time ogling its distinctive, square pinnules.

This aside, other new ferns included Soft Shield-fern (Polystichum setiferum), likely a new colonist at this site, and Hard Shield-fern (Polystichum aculeatum) which provided a nice opportunity for comparison. Other notable plants included Wood Horsetail (Equisetum sylvaticum) and Marsh Hawk’s-beard (Crepis paludosa).

The first true highlights came after crossing a small bridge in a deeper part of the Linn where we encountered an entirely new species for me in Beech Fern (Phegopteris connectilis). A rather rare species in our area, this fern is much more numerous in parts of Scotland, Cumbria and Wales were it favours woodlands dominated by Oak. It proved to be quite the lovely little plant.

Pausing for lunch about midway into the wood, we were pleased to stumble across a bankside strewn with Oak Fern (Gymnocarpium dryopteris) – a species I see very infrequently in the North East. This proved ample compensation for failing to find even a single example of Lemon-scented Fern (Oreopteris limbosperma) which I know from past walks inhabits the site also. Keen to add a few more species to our swelling tally, from here it was a straight hike to the site’s famed waterfall where a few more species awaited.

Arriving at the waterfall, we were pleased to note several examples of Hart’s-tongue (Asplenium scolopendrium), a typically common fern that had proved conspicuously absent thus far during our trip. The real excitement here was to be found in the walls of the ravine however, where, alongside some nice examples of Brittle Bladder-fern (Cystopteris fragilis) the group found many examples of Lobed Maidenhair Spleenwort (Asplenium trichomanes subsp. pachyrachis) – this being the only place you can see this lovely little fern in all of Northumberland. The subspecies of Maidenhair Spleenwort differs from that we see in garden walls in having scalloped margins to the leaflets and grows mainly on limestone outcrops, typically where conditions are very humid.

Interestingly, I had also expected to find Green Spleenwort (Asplenium viride) on this outcrop also, having noted it on trips in 2020 and 2022. Hopefully it is still kicking about there somewhere…

More Beech Fern (*Phegopteris connectilis*)

I make that 15 fern species in just a few hours – not bad going at all. In reality, the total was 18 including Wall-rue (Asplenium ruta-muraria), Maidenhair Spleenwort (Asplenium trichomanes subsp. quadrivalens) and Black Spleenwort (Asplenium adiantum-nigrum) observed as we departed from Newcastle. All in all, the trip was a success and I would strongly recommend that anyone with a penchant for ferns pay Hareshaw Linn a visit. You will not leave disappointed.

A Winter Walk at Hareshaw Linn

A short account of a frosty trip to Hareshaw Linn in Northumberland last weekend

Hareshaw Linn, a designated SSSI near Bellingham in Northumberland, is a truly lovely spot. One which I have visited previously in summer (writing about it here) but never during the colder months. Given the site’s reputation as a botanical hotspot perhaps that is little wonder – most plants tend to vanish in winter – but keen to get out and about in the winter air, we thought we would give it a go anyway. We certainly weren’t disappointed.

Ferns are a real specialty of Hareshaw Linn with the wooded valley and shady slopes here playing host to myriad rare and unusual species. While many of the ground-dwelling species had been flattened by recent frosts, during our walk, we noted several species including Lady-fern (Athyrium filix-femina), Male-fern (Dryopteris filix-mas) and Hard-fern (Blechnum spicant). The scaly ferns had taken a battering but it was still possible to discern Golden-scaled Male-fern (Dryopteris affinis) and its cousin, Borrer’s Scaly Male-fern (Dryopteris borreri). Hard Shield-fern (Polystichum aculeatum) with its rigid fronds also proved numerous – a welcome change to other sites I have visited recently.

Brittle Bladder-fern (*Cystopteris fragilis*)

Ferns growing higher up on rocks and trees seemed to have fared better than their relatives on the floor. On tree trunks strewn throughout the gorge, we noted both Common Polypody (Polypodium vulgare) and Intermediate Polypody (Polypodium interjectum), while boulders held Brittle Bladder-fern (Cystopteris fragilis) too. Of course, the area around the waterfall proved most productive with both local specialties observed. Lobed Maidenhair Spleenwort (Asplenium trichomanes subsp. pachyrachis) can be seen in good numbers here at its only Northumberland site. Green Spleenwort (Asplenium viride) was harder to come by but still present.

Of course, ferns are not the only thing to appreciate about Hareshaw Linn. The site is rather beautiful in any season but now, in the depths of winter, looks remarkable clad in snow and ice. Given the sub-zero temperatures, the famed waterfall here had partially frozen making for an impressive sight. Better still was the presence of ice pancakes on the burn itself. Believed to form when foam floating on the water’s surface begins to freeze, this was the first time either of us had seen these. An impressive sight!

While everything looked more than a tad wintery at the Linn, signs of spring could also be seen and heard. The leaves of typical spring flowers such as Wood Anemone (Anemone nemorosa) had begun to appear and in the wood, various birds had begun singing. It was nice to catch the drumming of Great Spotted Woodpecker (Dendrocopos major) in particular.

Fern of the Week: Lobed Maidenhair Spleenwort

For our first plant profile, we’ll cover an unobtrusive yet beautiful little fern found in only a select few corners of North East England: Lobed Maidenhair Spleenwort.

This is an extremely rare plant that thanks to an unexpected trip to Hareshaw Linn in Northumberland, I recently had the chance to see for the first time.

Lobed Maidenhair Spleenwort

Asplenium trichomanes subsp. pachyrachis

Many of us are familiar with with Maidenhair Spleenwort (Asplenium trichomanes), the delicate, trailing fern adorning garden walls and other structures throughout our towns and cities. What you may not know, however, is that the UK is home to several subspecies of this lovely little fern, one of which is the Lobed Maidenhair Spleenwort (Asplenium trichomanes subsp. pachyrachis).

This unassuming fern grows on calcareous rocks such as limestone in shaded, humid settings. Often under rock overhangs, on steep valley sides or beside waterfalls, such as at Hareshaw Linn. Unlike it’s more familiar cousins, it is seldom found on mortared walls and is unlikely to crop up in towns.

A genuinely rare subspecies in the UK, Lobed Maidenhair Spleenwort is found at only a scattering of sites. A notable concentration can be found in south Wales, with a further cluster of records near Chester. Elsewhere, it is found sporadically in small populations at isolated sites.

This fern is widespread in Southern Europe, particularly in Spain, France and Italy, so may well be under-recorded in the UK.

The specific epithet trichomanes refers to a Greek word for fern

Lobed Maidenhair Spleenwort, spotted at Hareshaw Linn in Northumberland

Identification

Lobed Maidenhair Spleenwort is a small, tufted plant that often appears to grow flat against the surface of rock. Its narrow, green fronds are usually 5-30mm long and contain at their centre a dark, glossy mid-rib – a useful feature for seperating this group from Green Spleenwort (Asplenium viride). The pinnae or leaflets usually number in at 20-30 pairs and are arranged oppositely along the frond. All of this, however, appeals to other Maidenhair Spleenworts too, so what sets this subspecies apart?

The main difference between Lobed Maidenhair Spleenwort and other subspecies is the margin of pinnae. As its name suggests, those of this fern are distinctly lobed, almost scalloped. In contrast, those of other subspecies may be asymmetrical or rectangular but only slightly toothed. It may only be an anecdotal observation, but I think the lobes give the leaflets of this fern an arrow-like shape…

Given it’s similarities to other Maidenhair Spleenworts, it is little wonder this fern is poorly recorded. Sure, it may be rare, but it must be present unnoticed at further sites. Will you find it?

Distribution

In the North East, Lobed Maidenhair Spleenwort is restricted to just a few locations: one in South Northumberland (VC67) and three in County Durham (VC66).

In Northumberland, the most notable colony is found at Hareshaw Linn SSSI, where the species thrives on the humid rock faces surrounding the site’s waterfall. In County Durham, it has been recorded at two sites near Barnard Castle and on crags along the River Tees near Bowlees.

A festival of ferns at Hareshaw Linn

An account of a fantastic day spent exploring fern identification at the glorious Hareshaw Linn.

Ferns have always scared me a little if I am honest. Sure, I can identify the easier ones but by large, I often ignore them on my travels in favour of less intimidating flowers. That said, I have been keen to improve my fern identification skills for a while now and on Friday set out with a friend to one of the most fern-rich sites in Northern England.

Hareshaw Linn is SSSI designated for its rare ferns and bryophytes. A scenic river gorge sporting ancient woodland and a rather beautiful waterfall, it is a site I had always wanted to visit but had not yet had the chance. Until now. Expectations already high, I am pleased to say I was not disappointed with fourteen fern species observed during our stay, including several new for me.

Starting out

Having given only an obligatory glance to the Male Fern (Dryopteris filix-mas) during our walk in, it wasn’t long until the first of the day’s more interesting ferns was discovered. The pictures below show Lady-fern (Athyrium filix-femina) found growing beside the path through the gorge. A lovely, feathery species with distinctive crescent-shaped sori, the best way to identify them is, of course, to turn them over.

Next up, a new species for me and further into the gorge, it was great to finally stumble across Lemon-scented Fern (Oreopteris limbosperma). Quite a nice one to identify, the best way to tell it apart from the pack is that the pinnae decrease in size as they go down the stem. It also gives off a pleasant citrus smell when crushed.

Hardly worthy of a mention but two more abundant ferns were added here too: Bracken (Pteridium aquilinum) and Broad Buckler-fern (Dryopteris dilatata).

Feeling brave, further into the walk, we decided to take a quick look at some of the other Dryopteris on site. I think the fern pictured below is a Golden-scaly Male Fern (Dryopteris affinis) having ruled out the Narrow-scaly Male Fern (Dryopteris cambrensis) based on the length of the lowest pair of pinnules. It also didn’t seem to fit Borrer’s Scaly Male Fern (Dryopteris borreri) either but I’d be happy to be corrected!

Golden-scaled Male Fern (*Dryopteris affinis*)

Moving on, new ferns soon started to come thick and fast. First came the first of many Hard Shield Ferns (Polystichum aculeatum) spotted during the trip and secondly, lots of Hard Fern (Blechnum spicant). Feeling empowered by the earlier male fern, we also chose to take a closer look at the Polypodys growing alongside the river. With pointed tips and fronds which gradually taper towards the top and bottom, I think these were Intermediate Polypody (Polypodium interjectum).

Hard Shield Fern (*Polystichum aculeatum*)

Nine species and counting

Drawing closer to the waterfall, a quick detour from the track revealed another new species for the day: Oak Fern (Gymnocarpium dryopteris). With fronds split roughly into three triangles, this is another nice one to identify and another new species for me.

Reaching the waterfall, it was difficult not to be taken aback by the visible storm damage. The plunge pool beneath the waterfall was littered with the corpses of felled trees, likely brought down during Storm Arwen. I wouldn’t have liked to be here that night…

The plunge pool beneath Hareshaw’s waterfall

Back to the ferns, and Hareshaw Linn is the only North East site for the rare Lobed Maidenhair Spleenwort (Asplenium trichomanes subsp. pachyrachis). A nationally scarce subspecies of Maidenhair Spleenwort, the difference between them comes from the lobed, crinkley-looking pinnae. We saw many plants during our stay, all concentrated around the waterfall where they grow within cracks in the bedrock.

Here too, the steep cliffs of the gorge and fallen rocks beneath them held a number of other ferns. Some, like Hart’s-tongue (Asplenium scolopendrium) were somewhat common, though others much less so. Green Spleenwort (Asplenium viride) is a rare species locally and took some finding among the much more numerous Maidenhair Spleenwort.

Slightly more conspicuous, Brittle Bladder-fern (Cystopteris fragilis) could be seen in abundance too. The latter species concluded the day’s tally at a very respectable 14 fern species.

Other wildlife

While ferns were the purpose of the day’s trip, plenty of other wildlife was seen at Hareshaw Linn. The plantlife was particularly interesting with sightings of several species I see infrequently in the North East. Among these, Wood Horsetail (Equisetum sylvaticum), Wood Melick (Melica uniflora) and Marsh Hawk’s-beard (Crepis paludosa). Of course, several Giant Bellflowers (Campanula latifolia) were also a highlight.

The combination of beaming sun and rain showers did not prove overly encouraging to insects. However, we did see a few goodies including new hoverflies for me in Epistrophe grossulariae and Leucozona laternaria. Returning to the car park, the bee below was also spotted foraging on a Solidago sp. Thanks to Chris, this was revealed to be Grey-banded Mining Bee (Andrena denticulata), an incredibly rare species in our region.

Fern Biology

Gathering Spores

Sowing the Spores

Watch and Wait

Watch the Prothalli Grow

Signs of Life

A Few Problems

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Beech Fern

Identification

Distribution

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Dryopteris lacunosa at Blaydon

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Common Ferns

The Big Five

Localised Ferns

Rare and Scarce Ferns

Scarce Native Species

Some Exotic Ferns

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Lobed Maidenhair Spleenwort

Identification

Distribution

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Starting out

Nine species and counting

Other wildlife

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