Harts-tongue: does a deer tongue really look like this?
This is a common plant in the south west of England and especially so in many places in Dorset. The hart's-tongue fern (Phyllitis scolopendrium) can be abundant where the environment is suitable. It can be food in woods, especially woodland on hill sides, hedgerows, among rocks, on walls, on the sides of ditches, even inside water wells. In short, it likes warm, darkish, damp places.
The classic ferns have rather complex leaves but hart's-tongue has a smooth, shiny, undivided leaf in this familiar 'deer's tongue' shape which is so unique and enables it to be easily identified.
Hart's-tongue is, in fact, a 'spleenwort' which are a sub-family of the fern group. The spores are released from little brown 'pockets' that form on the back of the leaf. The Hart's-tongue is in leaf all year round but produces new ones each spring.
Adders-tongue: appearances can be deceptive
Adder's-tongue (Ophioglossum vulgatum) is a small plant you can walk by and not know it is there. It is little more than an inch or so high and it looks like the leaves of a flower that has just come up above the ground. It is really a case of getting down on your hands and knees for a good look at this. It is a bit like wild arum with a sheath enclosing a central spike. It is, however, a spleenwort (part of the fern family structure) and not an flower at all. I only found this thanks to help from a ranger at Durlston which is the only place I have knowingly seen it.
The plant is visible from May through until November; the central stem that is supposed to resemble a snakes tongue is not a flower spike in the conventional sense but it is the organ that emits the spores. This stem is not alwys present.
My book describes it as widespread and frequent in lowlands, especially in damp meadows, scrub and open woodlands on limestone soils and so I guess that is why it grows at Durlston! I have never seen it anywhere else and I understood this to be a rare plant, after all limestone is not that common a rock or soil type.
Rustyback Fern: bricks and mortar
I have to say that the rustyback fern (Ceterach offinarum) is a pretty insignificant little plant! If I had not set out to find it at the location at Durlston given in Ted Pratt's excellent "Wild Flowers of Purbeck" guide I would never have found it at all. It grows in cracks in limestone and particularly in the mortar of old stone walls so it gets little nutrient and so does not grow very large. It is an amazingly tolerant little plant and can withstand drought by curling up to protect itself and then it quickly recovers when it becomes wet again.
The fronds are green on the upper surface but if you turn them over and look at the back they have a silvery sheen when young but these become rust-coloured with age and that gives rise to its common name.
It is a member of the spleenwort order of ferns and was once used as a herbal remedy for spleen and liver disorders although I have no idea how effective this was. It apparently contains high concentrations of phenolic compounds such as chlorogenic acid and caffeic acid which may be a clue to its medicinal qualities; I am no chemist so I have no idea if this is so.
Hard Fern: a hard fern to identify?
Actually not all ferns are difficult to identify, some are quite unique in appearance and cannot be confused with any other. The hard fern (Blechnum spicant) is one such species and is not hard to identify at all! The fronds are very thin and give a 'serrated' appearance, a bit like a double sided comb perhaps? No other Britsh fern is like this and so can be named on sight.
It prefers acid soils and is found mainly in the east of Dorset in shady woods and hedgerows; I see it most frequently along ditches and stream sides. it apparently also occurs on rock ledges but as I don't climb rock faces I can not confirm that!
Some of the fronds die back in winter but others stay evergreen and so you can find the hard fern easily any time you are out and about in suitable habitat.
Polypody: money may not grow on trees ... butthese ferns do!
When out and about in Dorset's deciduous woodland from time to time you will find ferns growing up in the trees, quite often in mature oaks. I had seen this elsewhere but it was not until I went through details of the Dorset Wildlife Trust reserves when we first moved here to Dorset some years ago that I spotted something called 'polypody' listed on some woodland reserve species lists. My curiosity aroused I read up about it and went looking for it.
There are three types of polypody fern; common, southern and intermediate (also called western) and they are very difficult to tell apart especially when they are high up in a tree! To make things worse, where two different species of polypody grow close together they can also hybridise and you get something in between! Yelling them apart is a job fore the experts and so I just refer to them as polypody ferns (Polypodium agg.).
Polypody ferns can also be found on walls and rocks and even on roofs of old farm buildings. it also occurs on the ground on acid soils and it likes shady banks. They are not rare but they are certainly unusual so keep an eye out for them, especially if you are enjoying a woodland walk.
Maidenhair spleenwort: somewhat off the wall
Maidenhair spleenwort (Asplenium trichomanes) is a charming little plant with a rather unusual name. Spleenworts are members of the fern family with special structural characteristics. They do not usually grow in the ground like many other plants, instead preferring rocky or wooden substrates. Many spleenworts are found in fairly unique places like crevices in rocks on mountain sides and are quite hard to find but the maidenhair spleenwort is widespread and can be found on walls and rocks virtually anywhere. Bridges and garden walls are the usual places to find them but this one was on the disused platform at Wareham Station.
They are not difficult to identify as they are small plants, have a typical fern-like appearance, and have a distinctive black central stem off of which the 'leaves' form alternately, left then right.
I cannot find where the name originates from but presumably spleenworts were considered to be beneficial to the spleen if eaten, this may or may not be true and I do not suggest you try it to see!
Sea Spleenwort: seaside survivor
Not all plants are interesting with lots to have told about them and not all plants are really special to look at. Sea spleenwort (Asplenium marinum) is rather boring and a bit scruffy! That said, it is an uncommon plant and found in very restricted habitat.
Sea spleenwort is, I believe, the only member of the fern family that can tolerate salt from the sea and can survive in conditions other ferns would find impossible. It grows in crevices and cracks in rocks, often within the spray zone, a pretty inhospitable environment. That is probably one of the best indicators to identification; if you find a fern growing in exposed rock by the sea then it is a pretty good bet it is sea spleenwort!
Given the lack of nutrients in rock crevices it does not grow to be a particularly big plant and given the buffeting it gets from the wind it can look rather worn, wrinkled and faded.
Its entry in Wikipedia runs to just 30 words, I have managed more than that so I feel I have done this insignificant plant some justice and, perhaps, put it on the map!
Male-fern: and the invisible man
The male-fern (Dryopteris filix-mas) is probably the most common British fern and is found in damp woods, ditches, hedgerows and other shady places. It is certainly common in Dorset and is especially prominent in winter when there is little competition from other foliage.
The male-fern has big, bold, broad fronds, set alternately up the stem. The base of each stem is a little scaly but, in general, this is a very green fern. Although this is the male-fern please do not think there is a female-fern! Ferns reproduce asexually. There is a lady-fern but it is a totally different species
I was intrigued to read that the male-fern is steeped in country folklore. It was thought that the fern had the power to make anyone carrying it invisible! It seems, too, that the roots were dug up on St John's Eve, carved into the shape of a hand and then baked to make a charm to ward off witches and evil! I am not sure we still hold these superstitions, do we?
Narrow buckler fern: a tough call
There are many challenges for the casual, non-specialist, naturalist. Identifying narrow buckler fern (Dryopteris carthusiana) is certainly one of them because it has a very similar close cousin, the broad buckler fern. The problem starts if your not a fern expert by telling which ferns are actually bucklers in the first place!
Once you have decided it is a buckler then it is most likely going to be broad buckler (here in Dorset anyway). Closer inspection is needed to check for narrow buckler and there are differences that sound obvious but in the field are difficult to be certain of. Firstly, the broad buckler has large, broad, triangular shaped fronds whereas the narrow buckler has ... yes, much narrower fronds with almost straight sides apart from the pointed top end. Both species have scales at the base of the stem, narrow buckler are pale brown, broad buckler are much darker.
There are other differences which you can use to separate them but you will need a good field guide to establish the features of each. One other way to separate them is by the habitat in which you find them. Narrow buckler likes fen and wet woodland whereas broad buckler is more likely to be found in shady damp places (rather than wet) on acvid soils.
So broad or narrow buckler? It's a tough call.
Soft Shield Fern: add it to the armoury
In researching and writing about ferns in my nature notes I noticed a tendency for ferns to be named after armour! There is male-fern which seems to have derived its name from chain mail and the buckler ferns where a buckler is a shield buckled to the forearm. So now I have soft shield fern (Polystichum setiferum) for which I can find no notes about the origin of the name but the fern is undoubtedly shield shaped so I presume that is why it is a shield fern. The soft shield fern has soft fronds, there is a hard shield fern which are stiffer and more brittle.
The soft shield fern is a native of damp woods in the west of Britain, in Ireland and Iberia but it also occurs as far away as Turkey and the Crimea. It is an attractive fern that is often found in gardens and there are some cultivated varieties available from garden centres. This may account for why the only site I have found for it in Dorset so far is at Durlston in the woods near the castle which, some years ago now, were part of the castle gardens. Other 'introduced' plants occur here and I am guessing that soft shield fern was introduced in this way.
At first glance it looks like the common male-fern but closer inspection reveals various differences, but the most significant is the ornamental, attractive 'leaflets' on the fronds which, on the male-fern, are quite plain and uninteresting!
Lady fern: the feminine touch
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.
Royal Fern: a right royal fern
I have been unable to track down why this fern should be called the royal fern (Osmunda regalis), the best suggestion seems to be that it is due to its imposing size and stature. There is no reason why this should not be the case, of course, but it would have been far more interesting if King Peter the first had hidden behind one to avoid capture by elephants! What is interesting I suppose is that the royal fernmay have derived its Latin name from Osmunder, the Saxon name for the Viking god Thor. Regalis implies regal so the common name seems to be a direct link to its scientific name. Why it is connected to Thor remains lost in time it seems!
The royal fern can be found right across Europe and favours damp, even boggy, wooded areas. In Dorset I have not found it that often but where it does occur it is likely to be present in some profusion. At the Dorset Wildlife Trust at Tadnoll there is lots of it near the Tadnoll brook. In general this a fern that is declining due to habitat loss from drainage schemes and past over collection.
It is not evergreen like some ferns, creating new fronds each year from the ever increasing clump of roots. This can make the whole plant extremely imposing as it grows with age. It is quite unmistakable for anything else, it is really a right royal fern!
Wall-rue: will the wall rue the wall-rue?
Dorset's rivers have lots of bridges crossing them and many are built of limestone. It is always worth taking a look at these bridges to see how, despite being brick or stone, nature colonises them. Crustose lichens are usually well established on the upper stone surfaces but look over the sides and you will find plants, especially spleenworts, and frequently this one, the wall-rue (Asplenium ruta-muraria).
Wall-rue is common across Britain and is certainly well established on rocks, walls and bridges across Dorset. Some people think that these tiny plants harm the wall it is growing on by weakening the mortar but, in reality, the plant roots are so fine that they tend to cling on to the surface rather than eat into the substrate. The wall has no reason to rue the wall-rue!
As an aside, if you ever develop a dose of rickets then this is supposed to be a cure - how about that as a bit of chat to slip into the conversation at the next works party?
Black Spleenwort: a cracking little plant
Not many plants can survive on the limited nutrients and moisture afforded by cracks in rock faces or stone walls but many ferns can, usually the sub-family of spleenworts. The black spleenwort (Asplenium adiantum-nigrum) is certainly one of them. In fact it only grows on rocks and walls, mainly in the west of England.
You might ask "Why 'black' spleenwort, it looks green to me?". The base of the stipe (that is the stem to you and me) is black; or dark brown and so appears black. It may seem difficult telling all these ferns apart but of the ones occurring on rocks and walls this is the only one with a true 'fern' appearance forming a triangular shape with bigger and wider fronds (leaves!) at the base getting smaller as they go up the stipe (stem!). So although it might look like many other ferns by being this shape it is the only one of this shape that grows on rocks and walls. Does that make sense?
Given we do not have a lot of rocks and stone walls in Dorset black spleenwort is not that common here.
Broad Buckler Fern: the shield of the woods
Ferns take some getting used to and even after several years of trying I am till struggling to sort them out! I always find a good strategy with any form of plant or creature is to try and get to know the common species in any taxa as they are, of course, the most likely ones you will encounter in the field. This gives you a bench mark and then you can take a closer look if you encounter something you do not recognise. After the male-fern then next most commonly encountered species by my reckoning is the broad buckler fern (Dtyopteris dilatata) which is frequently found on woodland floors and shady hedgerow banks and is most common on acid soils and so the lower Poole basin is a good area for it.
It is a darker green than the male-fern but I think the overall shape of the 'leaf' or frond is more triangular than the fan shaped male-fern. The individual 'petals' on each leaf are more feathery than those of the male-fern which are more rigid in form. The broad buckler fern can be anything from one to three feet tall and is variable in size which can be quite misleading in itself so size is not a good indicator.
I often wonder how some plants get their names. According to my dictionary a buckler was a small round shield buckled to the forearm. Now looking at the broad buckler fern I cannot see any resemblance to this at all!
Bracken: the ubiquitous fern
I guess that of all the fern family bracken (Pteridium aquillinum) is the one that we could all name quite readily. Bracken seems to grow just about anywhere and everywhere. It is not only the most common fern in Dorset, it is the most common fern in Britain and indeed, in the whole world! Yes, we are all familiar with bracken.
Not only is it diverse in its choice of habitat growing on heathland, moorland, open woods, unploughed pasture and hedgerows, where it grows it is usually the dominant vegetation of the area totally swamping everything else and not giving other plants any light to grow. Sometimes bramble, campion or perhaps gorse compete but not much else can. A few insect species like bracken but not much else does. Unlike some other ferns it is not evergreen. It starts to grow in April and May and then it dies back in the autumn.
Attempts to control bracken by burning are doomed to failure as the plant has deep rhizomes that are totally unaffected by the flames and once the competitive vegetation goes so bracken is able to increase its grip. Indeed, unintentional heath fires can hasten the spread of this unwelcome plant.
Water Horsetail: breakfast for Rudolph
So, there is field horsetail, marsh horsetail and water horsetail (Equisetum fluviatile), I guess it is not difficult to work out which one you are most likely to find in ponds, lakes and slow moving rivers! Water horsetail is common in the muddy margins of fresh and in such suitable habitat there can be lots and lots of it. It has been designated an obnoxious weed in some places as it can be virtually impossible to get rid of once established.
Water horsetail is bright green all over with dark scales around the 'branch' joints and it is a tall, slender plant compared to some of the other horsetails. The stem is hollow and will collapse under very little pressure from a couple of fingers sqeezing it.
As with other species of horsetails it is adept at absorbing metals from the soil and is used for analysis and extraction of these substances. It also has some long standing medicinal properties but different parts of the world consider it to be cures for differeing ailments so I suspect none of these are really well founded. Horses refuse to eat it (why would they eat their own tails? [joke]) but reindeer apparently love it as it is so juicy. One animal's meat is another's poison I suppose!
Common Horsetail: rubbing up the wrong way
Although called the common horsetail (Equisetum arvense) its scientific name of Equisetum arvense means 'horsetail of the field' and flield horsetail might be a more acuate name for it as it is not as common as the giant horsetail, well not in Dorset anyway.
This plant is related to ferns and produce fertile spores rather than pollen to fertile eggs (or seeds) that one finds in vascular plants. The common horsetail produces a fertile stem with no 'leaves' just a spore dispersing head in March and then these die back to be replaced by the green foliage from May onwards lasting into October.
The common horsetail can be seen on waste ground, road sides and bare patches of ground almost anywhere, footpaths along old railway lines are a good place to see them. They can be a troublesome weed if they get established where they shouldn't - especially in gardens. Like other horsetails they are poisonous to livestock and yet the buds are eaten as a vegetable in Japan and Korea.
The plant contains several medicinal elements including silicon, potassium and calcium and has been used as a cure for chilblains and open wounds. It is also used as an abrasive to polish pewters and wood!
Giant Horsetail: a polished performer
Horsetails are curious plants. Related to ferns through their botanical structure but very different in appearance and life style.
Horsetails actually have two separate identities; the main 'green' plant that we may all be familiar with but, before that, it puts up a fruiting body which contains the spores. These can be seen from March to May, the sterile green stems follow and can be seen until October.
The giant horsetail (Equisetum telmateia) can be seen on waste ground where the soil is rich and, perhaps, a little damp. It is much larger than its three other frequently encountered cousins (field, marsh and water horsetails) with a central stem that is nearly white with dark rings where the 'branches' occur. The branches bend upwards. They usually grow in clusters and can make a fine sight when at their best in early summer.
Long ago horsetails were one of the most widespread, diverse and common plants on the earth, many as big as trees, and much of our oil and coal reserves come from those plants. Many species of horsetail have rough, abrasive stems and are used in many parts of the world for scouring and polishing metal objects, particularly those made of tin.
Marsh Horsetail: cud do better!
Horsetail's are pretty unmistakeable but deciding which specific species can be a bit tricky. Fortunately, the various species tend to have their own habitat preference and if you find a horsetail in damp meadows then it will almost certainly be marsh horsetail (Equisetum palustre). There are other differences between this and its cousins but you need a good field guide to help you with that although, in general, you will also find the 'fronds' are shorter and pointing upward in this species!
Where it grows it will usually be quite common, even abundant, but as many meadows have been drained for 'agricultural improvement' it is considered a declining species. It can be found in some profusion on Wareham Common in summer. It is poisonous to both horses and cattle and yet cattle frequently graze on the common and presumably do not touch this stuff! Cows do seem to know what is good for them and what is not.
Sadly, horsetails seem to be rather boring plants and no one ever takes any notice of them.