British trees,  Wildlife & Nature

The spirit of the alder

Time once again for another in my British trees series, and I’m going to take a look at the alder…

“Its very existence seems to hang on the proximity of water.”

Gertrude Clarke Nuttall, ‘Trees and How They Grow

If you’re walking along a river bank or by the side of a loch, it’s most likely that you will come across a grove of alder trees.   Alders aren’t spectacular in the way that oak or beech trees can be:  they don’t grow to a massive size, nor do they display brilliant colours in autumn.   What they have is a strong affinity for water, and this element is woven into their life cycle as well as their properties.

Alnus glutinosa, the common or black alder, is the only native alder in Britain.  It is widespread across most of Europe, and its range extends eastwards across Russia to Siberia, and south to Turkey and Iran.   It was introduced to North America, probably in the 1600s, and has become naturalised in eastern Canada.

Alders by Loch Caolisport, Kintyre
Alders by Loch Caolisport, Kintyre
Alders by Loch Etive
Alders by Loch Etive

To ecologists the alder is a pioneer species, being one of the first trees to colonise clearings in a forest.  Rarely does it grow to more than 70 feet or live longer than 150 years.  This is a true water-lover, hugging the banks of rivers and lochs, and flourishing in damp meadows and boggy areas:  if its roots are in water, the alder is happy.

Alder is monoecious, producing male and female flowers on the same tree.  “Clusters of new and pointed female catkins typically develop over winter.  These expand into green, cone-like structures during summer, blackening over winter.  They release their tiny seeds the following year.”  (Gabriel Hemery, ‘The New Sylva‘)  More showy are the dangling male catkins, golden lambs’ tails that look like hazel at first glance – but on closer inspection you’ll see they are slightly shorter than hazel catkins, and more compact.

Old female cones (brown); younger female cones (upright, greenish) and male catkins (greenish yellow)
Old female cones (brown);  new female catkins (small and upright, greenish) and male catkins (long, greenish yellow)
Female catkins ripening into cones. The twigs are sometimes sticky to the touch, hence the name 'glutinosa'.
Female catkins ripening into cones. The twigs are sometimes sticky to the touch, hence the name ‘glutinosa’.
Female cones in winter
Female cones in winter

“When the seeds fall ripe from the parent tree and are seeking a lodgment, they are not furnished with wings or parachutes for flight, as are those of the sycamore or the poplar;  but they are provided with airtight cavities inside their walls, so that they will float unharmed along the surface of the stream or lake… Sometimes they may be in the water all the winter;  sometimes they do not fall till the spring, and their voyage is short;  but one day it ends – perhaps the stream subsides a little – and they drift to the shore, and there in the soft mud they may germinate.”

Trees and How They Grow’ by G Clarke Nuttall (1913)

The oval – almost pear-shaped – leaves of alder are quite distinctive, being indented rather than pointed at the tip, which makes them easy to distinguish from hazel.  They are bright green and deeply veined, often with a serrated edge.

Alder leaves and catkins 1While the mature bark can be brown or dark grey, young alder branches are smooth and often greenish in colour.  New shoots may sprout naturally from the base of the trunk.  Alder trees are often found in the company of birch and willow.

Alder (3)

Lichen on alder trunk
Lichen on alder trunk

Alder is a food plant for several moths including the delightfully named alder kitten (its head, body and legs are just as furry as you’d imagine);  alder catkins are an early source of nectar and pollen for bees, and the seeds are eaten by birds such as siskins and redpolls.

Alder with catkins near Keills Chapel in Knapdale
Alder with catkins near Keills Chapel in Knapdale

The alder has an important symbiotic relationship with a bacterium, Frankia alni, which forms nodules on its roots.  These absorb nitrogen from the air and make it available to the tree;   in return, the alder provides the bacteria with carbon.  In this way, alder improves the fertility of the soil where it grows, creating nutrients for species that follow it onto new ground:   “The nitrogen-fixing nodules on the alder’s roots improve soil fertility and so make this tree ideal for reclaiming degraded soils and industrial wastelands…”   (Trees for Life)

“There are a sort of husbands who take excessive pains in stubbing up their alders, where-ever they meet them in the boggie places of their grounds, with the same indignation as one would extirpate the most pernicious of weeds;  and when they have finished, know not how to convert their best lands to more profit than this (seeming despicable) plant might lead them to, were it rightly understood.”

John Evelyn, ‘Sylva’, 1664

The Crannog Centre, Loch Tay
The Crannog Centre, Loch Tay

As a wood, the great strength of alder is its resistance to decay, even under water – in fact, once it has been submerged, it gradually becomes as hard as stone.  For this reason, ancient people chose it for building tracks and bridges over marshy ground, and crannogs stood on beds made of alder trunks.  But once it is taken out of the water and exposed to the air, alder quickly begins to decompose.

The cities of Venice and Amsterdam were built mostly upon alder timber piles.”

Gabriel Hemery, ‘The New Sylva

Woods and shoreline south of Ballachulish
Woods and shoreline south of Ballachulish

The Ballachulish ‘goddess’

In 1880 a small but enigmatic female figure, carved from a single piece of alder with pebbles for eyes, was discovered in a peat bog known as Ballachulish Moss on the shore of Loch Leven.  It is thought to date from somewhere between 728 and 524 BC, and is currently on display in the National Museum of Scotland.

Alder trees in place names

In England, names such as Allerton, Allerbeck and Ellerslie recall the existence of an alder wood.   The old Gaelic word for alder is ‘feàrn’, and there are plenty of occurrences of this throughout Scotland and Ireland.  The author Gavin Maxwell’s house was called Camusfeàrna’, the ‘Bay of Alders’.   The Welsh form is ‘gwern‘, sometimes mutated to ‘wern’, and these crop up so often in the east of Wales that historians have wondered whether alder trees were grown there commercially in medieval times, so that their timber could be sold to rich Norman estates in Herefordshire and Shropshire.   The theory is that the wood may have been made into clogs for farm workers.

Waterlogged alder woods are called carrs, and this has also been preserved in some English place names.


‘Sure-hoofed is my steed impelled by the spur;
The high springs of alder on thy shield;
Bran thou art called, of the glittering branches.

Sure-hoofed is my steed in the day of battle:
The high sprigs of alder are in thy hand:
Bran thou art, by the branch thou bearest
Has Amaethon the Good prevailed!”

Traditional Welsh englyn associated with the Cad Goddeu (‘The Battle of the Trees’) in the Book of Taliesin

In the Welsh Mabinogion, the alder tree is the emblem of the Celtic giant-god, Bran.  One story tells how Bran’s sister, Branwen, was being mistreated by her husband, Matholwch, the King of Ireland.  Bran calls his men together and sets off to rescue her;  when they come to the River Llinon, they find that the only bridge has been dismantled on the orders of the Irish king, so Bran lies down across the river to allow the men to pass over his body.  This may be a reference to the alder’s natural empathy with water.

Alder - male catkins (1)

Alder was the tree of prophecy and sacrifice, and a shield made from its wood was believed to imbue the carrier with ferocity and protection in combat.  Once it has been cut down, the pale wood of alder turns deep orange and releases an orange-red sap, and it may have been this phenomenon that convinced early warriors of its power:   to them, it appeared that the alder’s spirit was bleeding and would thus prevent them from being wounded themselves.   Warriors became deeply attached to their shields;  in Irish mythology they were given individual names and believed to have magical powers in their own right.

However much they loved the qualities of its wood, the Irish considered it unlucky to pass an alder tree on a journey.   This may derive from the fact that alder groves were usually dark, boggy places where evil spirits were thought to dwell.  Given the widespread distribution of alder, I’m guessing that this must have led to some pretty roundabout routes!  And just to compound the problem, it was also believed that putting some alder leaves in your shoes at the start of a long walk would cool the feet and prevent soreness.  Plenty of careful planning must have been the secret here!

Glen Etive 21Deirdre of the Sorrows…

According to an Irish legend, the royal storyteller at the court of King Conchobar mac Nessa had a beautiful daughter named Deirdre.  She was destined to marry the King, but she fell in love with Naoise, a handsome warrior.  To escape the King’s wrath, Deirdre and Naoise fled across the sea to Scotland where they hid in the alder woods of Glen Etive.

But there was no happy ending:  they were tracked down by Conchobar’s men who murdered Naoise and brought Deirdre back to Ulster where she was forced into marriage.  One version of the story says that she took her own life by throwing herself from a chariot.  Is there any more romantic name than Deirdre of the Sorrows?

Alder (6)Dyes made from alder flowers were once used to colour fabric for garments, and folklore says that fairies’ clothes were dyed with alder pigment to conceal them from human eyes.    Three colours could be obtained:  brown from the twigs, red from the bark and green from the flowers.  Both the bark and the wood contain tannin, used for tanning leather.

Alder burns with an intense heat, making it an ideal fire for forging weapons, and some Bronze Age archaeological finds have revealed the use of alder to make charcoal.  Smoke from alder fires was used for divination, as was the movement of the flames.  On the living tree, omens were seen in the way the branches moved in the wind, and heard in the rustle of its leaves.   Whistles made from alder wood are said to summon the wind and enlist the help of benevolent water spirits.

Since 1956, the guitar manufacturer Fender has been using alder to build the bodies of its electric guitars, including the legendary Stratocaster.    (To be precise, the species used is the red alder, Alnus rubra, native to the west coast of America.)   But who knew that the unmistakeable notes of Mark Knopfler and Eric Clapton owed their tone to alder wood?  Fender’s website explains:  “It has a resonant, balanced tone brighter than other hardwoods… It imparts excellent sustain and sharp attack.”

Fresh alder leaves are said to make a good insect repellent, although I haven’t tried it myself.  As a treatment for rheumatism, dried alder leaves may be placed in a bed or sewn into a cushion.  It has antibacterial properties, and herbalists have prescribed it as a gargle for a sore throat.  A decoction of alder bark was traditionally used to treat burns, wounds and inflammations, and alder tree essence is said to relieve anxiety and nervous tension.

Alder fruits


“The alder is of all other the most faithful lover of watery and boggie places, and those most despised weeping parts, or water-galls of forests…” 

John Evelyn, ‘Sylva’


Photos copyright © Colin & Jo Woolf


Hawthorn berries (2)More in my British trees series…


    • Jo Woolf

      Thank you very much, Bella and Esme! (And to your Mum!) You are very kind. 🙂 I love finding out about the folklore of trees, and the alder was especially interesting.


    Thank you for a really interesting exposition on a tree that I’ve often passed without really noticing, though it is very common in these parts – seedlings everywhere, but Manche is a pretty wet Departement! I didn’t know about the insect repellent qualities – to me the best fly protection is elder rather than alder! I can remember riding horses which unaccountably thrust their heads into the bushes and refused to move, on fly-busy days.

    • Jo Woolf

      So glad to know you enjoyed it, Viv. I learned a lot while reading about the alder. Like you, I have often passed it without really noticing or identifying it – but no longer! That’s really interesting about the horses – they obviously know far more than we do!

    • Jo Woolf

      Thank you, Lynne! This whole thing started partly because I didn’t know much about trees either. I have learned to recognise many kinds now! There’s so much of interest in the folklore and natural history as well.

  • justbod

    Another great article – thank you! I’ve never really read about the Alder before and found it fascinating. Didn’t know about its underwater property. Great mix of fact, history, myth and folklore – thanks again 🙂

  • tearoomdelights

    Very interesting, as this series always is. Your photographs are a wonderful accompaniment to the rich and varied text. I think the alder is one of those trees that gets a bit overlooked, but it obviously has some unique talents. I was particularly struck by the point about it becoming as hard as stone in water, and about it ‘bleeding’ and protecting warriors in combat. That alder kitten moth you linked to is delightful. 🙂

    • Jo Woolf

      Thank you very much, Lorna, and I’m very glad you found the alder as interesting as I did. There’s just so much folklore connected with trees, and I could get completely absorbed in those old legends. I agree with you about the alder kitten! How cute is he?!

    • davidoakesimages

      Jo….I should have added that we live in what was once the village of Allestree. As the village has at its heart a Church, Local historians have linked the name to Saints…Alliards tree. But none that I have read have linked it to Alder. Yet Allestree is on bluff above the river plain of the Derwent and there was much woodland around and there still are many Alder along with other natives.

      • Jo Woolf

        That’s very interesting! You could be right there, David – I agree with your suggestion, although I would not wish to offend St Alliard who may well have a long and vested interest! 🙂

    • Jo Woolf

      Thank you very much! I love the myths and legends too, and I could get drawn into them with all their magic and hidden significance. I’ve no idea yet what the next species will be – perhaps juniper, but then there’s also ash, wild cherry, elm, willow, aspen, and many more – enough to keep me going for quite a while!

  • Di

    So glad I came across your very informative article. Our house is called “Alderstone” and now I know what it means! Thank you and I’m looking forward to reading the rest of your series.

    • Jo Woolf

      That’s so good! I am delighted to hear you’ve enjoyed this and it could not be more fitting with the name of your house! 🙂 Thank you for your comment!

  • Terry

    Gavin Maxwell’s house was not on Skye but on the mainland, the house is gone but the site is very atmospheric.

    • Jo Woolf

      Thanks, Terry. I should have known that myself, as I went past there many years ago. I know where it is – near Glenelg, in a very tranquil spot.

  • Matt Beamish

    Hi Jo,
    thanks for putting this together – it’s very interesting. Could you give me a specific reference for “d a shield made from its wood [Alder] was believed to imbue the carrier with ferocity and protection in combat.” It would help me with some research that I am doing.

    • Jo Woolf

      Hi Matt, thanks for your enquiry! I’m just taking a look into this and will probably drop you an email as it’s more direct. With best wishes, Jo

  • Angela Stoffregen

    This article is fascinating. I came upon it while researching the meaning of my grandmother’s name, “Nelda”. A couple of Internet sources say that the Anglo-Saxon meaning of it is ”from the alder”. I’m brainstorming names for my business, I like the idea of using the word “alder” in the business name because of this connection to Nelda. Thank you for all of this information and folklore.

    • Jo Woolf

      You’re most welcome Angela! That’s really interesting about your grandmother’s name. I haven’t heard the name of Nelda before, and it’s lovely. I think it’s a great idea to include alder in your business name! Wishing you every success. – Jo

      • Miranda

        I’m glad I found this article – my home is on the banks of a small river in Wales, and the land has many tall, beautiful Alders, so it was good to learn more about them. One with a twin trunk grows straight out of the riverbank near the house and its roots trail downstream in the water. It was interesting to read about its use in dyeing cloth; the leaves leave an exceptionally strong brown print behind where they fall on the patio paving in autumn. The house was originally a small woollen mill and I wonder if Alder was used to dye the cloth as it’s so abundant here. Thanks for the article, I enjoyed reading it.

      • Jo Woolf

        Thank you very much, Miranda, I’m really glad you found this interesting! Lovely to hear about the alders growing near your house. There are loads around here too – always near water (and there’s plenty of that!)

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