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Platanus - the planes

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Birthday Tour (Part 3): Loch Tay & the Ardeonaig Sycamore - Killin

…Continuing from Part Two, in which I visited the Glen Lyon Ash.

I don’t think I have ever seen Loch Tay looking so beautiful as it appeared on my 27th birthday – the whole scene was absolutely breath-taking. This is the view west towards the Killin end of the loch…

…and this is the view east. The town of Kenmore (which I had just driven through on my way from Fearnan) can be made out at the point where the River Tay, the longest river in Scotland, exits the loch en route to Perth and Dundee.

Blue skies, snowy mountains, and reflections in a still loch… lovely!

This monster sycamore grows close to the hamlet of Ardeonaig, beside the road which runs just to the south of Loch Tay along its full length between Killin and Kenmore. I’m calling it the Ardeonaig Sycamore, although a more fitting (but probably misleading) name may be the Ardeonaig Plane Tree, as that was the common name for Acer pseudoplatanus once in common usage in Scotland. I discovered this tree last June, being immediately struck by its immense size as I walked by on the Rob Roy Way with a couple of friends (although I had driven along this road at least a couple of times previously without spotting it).

The trunk – and these photos don’t do it justice – really is enormous. It’s just a solid wall of wood. Unfortunately, I didn’t have a measuring tape with me and so can’t provide an accurate size. As you can see, before long the trunk branches into three major stems. Each one would be a respectable sycamore on its own!

When the trunk is examined from the lane, as in the above photo, or when the whole tree is admired from down the lane in either direction, the Ardeonaig Sycamore appears to be in exceptional health. The crown is full and healthy and the stem is flawless – for a tree of such outstanding stature, the expected depredations of age are surprisingly absent.

However… This time I climbed up the little banking / decrepit wall to get a look at the back side of the tree, only to be equally surprised at the amount of decay visible back there! The back half of the tree tells a completely different story to the front half. It appears as though the Ardeonaig Sycamore once had four massive stems, but at some point the back stem broke off completely, probably falling harmlessly into the field behind. In the photograph above, taken looking up at one of the remaining stems, the bottom half of the picture is almost all decaying wood and the associated new growth (the fourth wall of CODIT). The presence of this significant amount of decayed wood right at the base of this huge stem has worrying implications for the tree. I cannot envisage this stem remaining upright for long. In fact, with this amount of decay where all three major stems join the main bole, I would say that in all likelihood this tree is close to disintegrating, with one, two, or all three of the remaining stems falling outwards.

This photograph of the eastern side of the tree shows part of the old wound created when the fourth stem snapped out. Presumably decay was already present to cause that stem to fall, unless it was broken by entirely mechanical forces; however, a wound of this size has undoubtedly promoted further decay, and now the enormous bole is actually mostly hollow at ground level. This is a massive shame. When I came across the Ardeonaig Sycamore last year I thought I had discovered something really special: an enormous veteran tree enjoying the good health of youth. Now I know that it was only putting on a brave face.

And here is one more view of Loch Tay – I can’t resist!

Having left behind the Ardeonaig Sycamore (and Glen Lyon Ash and Fortingall Yew), I made my way to Killin and stopped for refreshment at the Falls of Dochart Inn. The Falls themselves were in low flow and very tame. Unfortunately, before long I had to tear myself away from this enchanting part of the country and make a start on the drive back to Edinburgh… Still, I trust it shan’t be too long before I’m back up at Loch Tay. I am well and truly under its spell!


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Coming soon: a long-awaited update on the Set A grey alders…


Posted in Holidays and field trips + Notable trees





Summer in March: A walk on the moors

A couple of days ago I returned home from half a week on Mull & Iona, where I saw an enormous fossil tree… but that’s another post! The weather up there was for the most part dull and drizzly, and in Sheffield today it put down a few inches of late snow. Yet before I went away we had some incredible weather at home. It was like high summer, but in March…

Holt House, an abandoned farm on the other side of the Ewden valley, stands close to some quite old and fairly gnarly trees. In the foreground, Rhododendron ponticum is colonising the moorland – it has already claimed the valley side down to the river. It would be the mother of all nightmares to eradicate at this stage, and it gets worse every year.

Park Cote, the walled area, is on the same side of the valley as Holt House. With another abandoned building or two (they draw me in!), it’s been on my list of Places To Visit for a while now.

A typical Oaken Clough scene: a lovely, big, lichen-encrusted birch, plus rowan, more birch, bracken, moss, holly, heather, lichen-encrusted rocks, a wee burn… it’s paradise.

Birch.

A rowan in its prime leans out over Ewden Beck high up the valley. The river was very low; much of the riverbed was exposed and dry. This section is bare bedrock.

A close-up of one of the exposed stumps you sometimes stumble upon out on the moors, usually in groughs: relics from a time long ago when the moor was not a moor but a wood. The peat preserves the timber really well.

A larch rose in the making! I love larch roses. They can’t fail to put a smile on your face.

Holt House again, surrounded by mature sycamores. Today it’s just a deteriorating shell, but when I win the lottery (once I’ve started playing the lottery) I’ll do it up and turn it into treeblog HQ. That’s the dream!


Posted in Gone for a walk





Mushrooms of Langsett (Part Two)

…Continued from Part the First.

The black patches on this sycamore (Acer pseudoplatanus) leaf, known as tar spots, are the fungus Rhytisma acerinum. Those clusters of red spots are galls caused by the mite Aceria macrorhynchus. Neither have any significant impact on the host tree.

A razor strop or birch polypore (Piptoporus betulinus) juts from a dead downy birch (Betula pubescens).

An immature fungal fruit body begins to emerge from the soil. Maybe an Amanita?

?????

As above.

I’m fairly sure this is a Suillus something - perhaps a dried-out slippery jack (S. luteus)?

Another Leccinum, but which one? There is so much variation within the different species, I just can never say with any certainty. Could this be a blushing bolete (L. roseofractum)?

Hawthorn (Crataegus monogyna) and a dry stone wall – a lovely combination. At this time of year the hawthorns are covered in little red fruits called haws. I suppose you could make a jam from these (edit: of course you can!).

Looking up into the rather open crown of the same hawthorn (or one of its neighbours).


Posted in Gone for a walk





Holiday snaps from the French Riviera

Whizzing past a vineyard in the south of France.

I flew to France with three mates a couple of weeks ago. We landed at Nimes, picked up our hire car, and set out on a six-day jaunt along the Côte d’Azur taking in Marseilles, Toulon, Saint-Tropez, Cannes, Monaco, Nice and Arles. It was awesome. A few observations: the French don’t know what real tea is / beer costs twice as much as it does in the UK / the French aren’t afraid to bash into things (other cars, bollards, etc) when parking / the French don’t appear to drink milk (or chocolate milk) / London plane (Platanus x acerifolia) is the street tree of choice / street trees and trees at campsites are almost all kept perpetually pollarded and/or subjected to extreme butchery! (And never, ever take your car into a French multi-storey car-park if you value your paintwork.)

The top of a pollarded London plane. All those wounds are bound to let in disease, and most of the trees were partially or entirely hollow. I have a photo of my friend stood inside one!

This square in Saint-Tropez was lovely with its dozens of plane trees. I wish we had somewhere like this in Sheffield!

Pine trees at one of the campsites. These pines grew in great abundance everywhere but I don’t know what species they were.

This olive tree (Olea europaea) stood in a beautiful public garden in Monaco. Judging from the size of its base, I’d say it was very old indeed.

I think this is some kind of fig tree (Ficus), but again I don’t know the species. There were quite a few growing in Monaco. I thought these buttresses made a good throne.

Some of the figs were dropping aerial roots down from their crowns. This group had almost reached the ground.

Another fig’s buttresses had formed a impressive wall!

Palm tree, Saint-Tropez.


Posted in Holidays and field trips





Spring is sprung

The weather did an amazing impression of summer this weekend. On Friday I went for a little walk to take in some of the spring greenery that has suddenly appeared. It took me past this picturesque hawthorn (Crataegus monogyna) that grows in the field between Whitwell Moor and Hunger Hill.

These pictures of a neighbouring hawthorn show how far along they are in unfurling their new leaves.

What a tangle!

I’m looking forward to seeing all the hawthorns clothed with white flowers in a couple of months, but right now it’s great seeing them clothed in green again.

Hole in the bole.

Looking down into Ewden Valley from Heads Lane.

Sycamores (Acer pseudoplatanus) are beautiful at this time of year with their unblemished leaves illuminated by the sunlight.

The bluebells are out in Yew Trees Wood!

I saw these catkins on a male goat willow (Salix caprea) in Ewden Village. My friends’ new house has a female goat willow growing in the garden – it too was covered in catkins yesterday.

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April’s edition of the Festival of the Trees is hosted by Georgia of local ecologist. Go read!


Posted in Gone for a walk





Hallowe'en (Part One)

After a night in town dressed as a zombie steel-pirate, I required a dose of fresh air to purify my brain. There’s an old barn I found photographs of on Flickr that I’ve been wanting to visit for a couple of weeks now, so that’s where I headed: Swinden Barn. It was a very foggy day.

My eyes were drawn by a young field maple (Acer campestre) standing out from the misty gloom with an impressive display of yellow autumn leaves.

This auld track goes by the name of Badger Lane. It is home to a rather haphazard avenue of oak trees.

Each cobweb drooped under the weight of a thousand tiny jewels.

Part of Badger Lane is lined with some really strange trees that look as though, at some point in the dim and distant past, they were trained to become a hedgerow. But these trees aren’t the species to make a hedgerow: downy birch (Betula pubescens), horse chestnut (Aesculus hippocastanum), sycamore (Acer pseudoplatanus). What is the story here?

This sycamore grows immediately to the right of the one in the previous photo. They might well be the same tree. Viewed as a whole, it is one long tree.

Swinden Barn. It is the only remaining building of Swinden Farm, which was apparently occupied until the 1930s or 1950s and demolished in 1991. The barn is in good condition. It’s hard to see from my photograph, but the end wall on the left shows that a smaller building was once attached to it. The end wall on the right, which cannot be seen at all in my photograph was very interesting in that it is covered with another wall built of uncut stone in the style of a dry stone wall. It didn’t look as though this was once the end wall of another building, so what was it built for? Another wall close by the barn has stone shelves built into it. A very interesting place indeed – how I wish I could see how the place looked when the whole farm was there (working time machine required). From the Peak District National Park Education Website:

Farms in the water catchment area of the reservoirs were seen as a danger to the purity of the water… The water catchment area was ‘sterilised’ by eliminating any cattle from the land around. Sheffield Corporation Waterworks therefore allowed a policy of depopulation of the farmed land around the reservoirs to control pollution of the water catchment area.

In the Swinden area, (whose name Swine Dean meant the wooded area where pigs foraged for acorns) there were five farms which all fell into decay. Swinden Farm was the last to be abandoned and was lived in until the 1930s.

[To put all this into context, the nearby Langsett Reservoir is the one that necessitated the depopulation of these farms. Work on the reservoir started in 1889 and it was completed in 1904. Another of the five depopulated farms is North America Farm, which I have been to loads of times; I don’t know anything of the other three.]


In this part of the woods fallen larch needles had coloured the floor a strange butterscotch hue. This photo doesn’t do it justice.

After descending down a steep slope I was pleasantly surprised to come out on the banks of the Little Don River, only a few hundred metres upstream of… (To be continued).


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Hallowe’en (Part Two)
Hallowe’en (Part Three)


Posted in Gone for a walk





Spring and decay (24th April 2010)

A European larch (Larix decidua) female flower. The larch roses have arrived later than they did last year, but they were out in force last weekend when I went to check on the progress of the Set A grey alders.

A mature birch polypore a.k.a. razor strop (Piptoporus betulinus) bracket on a fallen downy birch (Betula pubescens). Razor strop fruiting bodies are annual; this is one of 2009’s.

Wee mushrooms growing on another fallen birch.

A gnarly, lichen-encrusted rowan (Sorbus aucuparia) twig with unfurling leaves.

A pair of sycamore (Acer pseudoplatanus) seedlings growing in the fork of a mature sycamore.


Posted in Gone for a walk





Pests, diseases, disorders, competing growth and unfavourable conditions (a field trip): the diseases

Last Thursday my arboriculture class set out from college on a field trip to see a smörgåsbord of pests, diseases, disorders, competing growth and unfavourable conditions afflicting a variety of trees in the vicinity of York and Malton. Some of them were new to me, most I were already aware of, but it was a highly interesting way to spend a day and we got to see some cracking trees. Here’s a quick run-through of the diseases that we saw:

Supermassive sycamore (this photo falls a long way short of doing it justice) with decayed Dryad’s saddles. The one on the floor has fallen off the tree.

Dryad’s saddle (Polyporus squamosus) – A bracket fungi. Described in Jordan’s Fungi 1 as “Large, creamy-brown scaly cap with cream pore-bearing under-surface, annual; parasitic on broad-leaf trees, also on stumps, favouring beech, elm and sycamore.” We only saw old and decaying specimens, but the sycamores (Acer pseudoplatanus) they had grown on were jaw-droppingly colossal - easily the biggest I’ve seen! These ancient sycamores formed an avenue along a road near Birdsall House. I’ve got to go back and get some decent photos of them in the summer before they collapse or get felled for safety reasons.

These crazy patterns are galleries produced by elm bark beetles.

Dutch elm disease – The Big Baddie. The current epidemic is caused by the fungus Ophiostma novo-ulmi, spread by elm bark beetles of the genus Scolytus. It is the most catastrophically devastating tree disease ever recorded in British history. On the field trip we saw a dead elm (Ulmus) replete with bark beetle galleries in the wood beneath the bark.

Cankers on a sycamore.

Canker – There are various kinds of cankers and a variety of causes of cankers. Strouts and Winter 2 define a canker as a “clearly defined patch of dead and sunken or malformed bark”. We saw cankers on sycamore and red horse chestnut (Aesculus x carnea) - a hybrid amusingly described in the Collins Tree Guide 3 as a tree of “rather endearing ugliness”.

Huge ivy-covered canker on a red horse chestnut.

Razor strop on silver birch.

Birch polypore or razor strop (Piptoporus betulinus) – Another bracket-producing fungus, it is restricted to birch (Betula). We saw loads of razor strops on dead and drying silver birches (Betula pendula) in a small piece of woodland that has become waterlogged as a consequence of mining subsidence.

Ganoderma on a veteran English oak.

Ganoderma - A genus of bracket- (polypore) producing fungi that is parasitic on broad-leafed species. We saw a large, dead Ganoderma at the base of a huge and ancient English oak (Quercus robur), but we didn’t identify it to species level. The oak was extremely diseased and its days are sadly numbered.

Slime flux on the same oak.

Slime flux or bacterial wetwood – A bacterial infection causing the host to ooze infected sap from wounds or apparently healthy bark. According to Strouts and Winter 2, bacterial wetwood is “common yet rarely results in overt disease”.

Inonotus hispidus on an ivy-clad ash.

Inonotus hispidus - Another polypore-producer that is parasitic on broad-leaves, particularly ash (Fraxinus excelsior). We saw several dead brackets on an ivy-covered ash growing by a stream.

Fomes fomentarius on silver birch.

Hoof fungus or tinder bracket (Fomes fomentarius) – Like you’d expect, the brackets of this fungus look like hooves. It favours birch – its modus operandi is similar to that of razor strop. We saw several of these brackets on the waterlogged birches.


1 Jordan, M. (2004). The Encyclopedia of Fungi of Britain and Europe. Frances Lincoln.
2 Strouts, R. G. and Winter, T. G. (2000). Diagnosis of ill-health in trees. The Stationary Office.
3 Johnson, O. and More, D. (2006). Collins Tree Guide. HarperCollins Publishers.


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Call for Submissions: Festival 44 Returns to the treeblog. Submit!


Posted in Pests and diseases





London planes by the riverside, York


Late summer; a summery resurgence. A hot day, a beautiful clear blue sky. A river: the Ouse in York. A riverside, an avenue of London planes. An icecream, a flake. The sun through the leaves, the sunlight plays on the water. Late summer perfection.

London plane (Platanus x acerifolia) leaves. No pom-poms.

London planes are a common sight in cities, being planted for their high tolerance of air pollution and soil compaction.

A goose on the Ouse. Photos taken yesterday.


Posted in Gone for a walk





Out on the bike: around Langsett and back (Part 3 of 4)

Continuing on from Part 1 and Part 2… my bike ride from the Sunday before last (24th May 2009).

A dandelion (Taraxacum officinale) seedhead in a forest clearing. An old English name for the species is blowball; I like that better than the current prevalent common name, a corruption of dent de lion, which is French for ‘lion’s tooth’ – a reference to the jagged leaves.

The leaves of a wild cherry (Prunus avium). The green balls on long stalks are the developing fruits.

Wild cherries have an obvious pair of red glands on their petioles: these are extrafloral nectaries. Whereas floral nectaries evolved to attract insects (and other creatures) to assist in the pollination process, certain plants have evolved extrafloral nectaries to attract predatory insects; these mercenaries keep down the populations of plant-eating insects.

Langsett Reservoir. It is surrounded by coniferous forestry plantations on all sides except the dam wall; further back, behind the trees, the moors stretch for miles to the west and south: Thurlstone Moors, Langsett Moors, Harden Moor and Midhope Moors. The reservoir is fed mainly by the Porter or Little Don, which enters from the west and runs out to the east; a couple of miles downstream that river flows into Underbank Reservoir.

These two photos were taken from the dam wall. When I first arrived at the spot, the reservoir surface was perfectly calm. After I’d stood there awhile, mesmerised by the water, the wind picked up and the surface became slightly disturbed. This caused the phenomenon seen in this photograph: yellow swirls along the water’s edge where it lapped against the stones of the dam wall. My guess is that the yellow swirls are pollen.

A sycamore (Acer pseudoplatanus) inflorescence.

A closer look. Sycamore inflorescences are complex, but I believe I can tell the male parts from the female at this range – I think the the wood-coloured ‘heads’ on stalks are stamens (♂), while the bright greenish-yellow, plumper, stalk-less ‘heads’ are stigmas (♀).

Common hawthorn (Crataegus monogyna) flowers. They have only one style, whereas the flowers of our other native species, the Midland hawthorn (Crataegus laevigata), have two or three.

I was made aware of the sad loss of two familiar trees on this bike ride. The first was the rowan near Upper Midhope; the second was a sycamore growing next to a farm building in Upper Midhope, shown here on the 26th of March 2007. It has been cut down. Perhaps the owner of the farm building is planning to do it up and sell it as a house, and while it was fine to have a tree growing next to an uninhabited barn, it wouldn’t do to leave one so close to a home. That’s just pure guesswork on my part, but come on Upper Midhope! What are you doing to your trees?


Posted in Gone for a walk





Out on the bike: around Langsett and back (Part 2 of 4)

The Porter or Little Don river just above Brookhouse (or Brook House) Bridge. This little section looks nice in the photo but I tell you it’s ten times better when you see it in the flesh on a sunny day. Every time I’ve been there on such a day, as last Sunday was, there’ve been people sunbathing on the flat grassy area and kids playing in the river. I sat myself down on a large, flat stone poking above the water and let the river cool my feet. The babbling of the burn and the beautiful surrounds were highly relaxing and I reposed for almost an hour. The presence of all the people playing and chilling out (there were more than in the photo when I arrived, and there were many more behind me) added to the carefree, summery atmosphere, whereas normally I’d rather be away from the general public while enjoying the countryside.

A lovely, pebbly bit of riverbed next to my rock.

A large sycamore (Acer pseudoplatanus) – just right of centre in the first picture – and Brookhouse Bridge. All the stones in the lower right have built up behind a large weir, built to prevent such sediment from entering Langsett Reservoir, which isn’t much farther downstream. The bridge takes its name from Brook House farm, which had to be abandoned to prevent its livestock polluting the reservoir – Langsett was built to supply the rapidly-growing population of Sheffield with drinking water. There are old books and magazines describing the farm’s unusual rent, payable to the lord of the manor (a modern book has it being paid in 1588, but the older books imply it was a annual arrangement over several years):

BROOK HOUSE, Yorkshire.--A farm at Langsett, in the parish of Peniston and county of York, pays yearly to Godfrey Bosville, Esqre., a snowball at Midsummer, and a red rose at Christmas.

[ - from A righte Merrie Christmasse!!! The Story of Christ-tide by John Ashton (1894).]

Estates have often been held by the tenure of a rose – a red one – at times being stipulated for, and these floral tributes generally had to be paid on St. John the Baptist’s Day… For Brook House, Langsett, Yorkshire, it is said that a rose had to be provided at Christmas, and a snowball at Midsummer, and as evidently there would often thus be much difficulty in paying the rent, we are probably correct in surmising that in this case a money fine was the alternative.

[ - from Hardwicke’s Science-Gossip: An Illustrated Medium Of Interchange And Gossip For Students And Lovers Of Nature, Volume XVII, edited by John Eller Taylor (1881).]

The weir and the sycamore.

A wych elm (Ulmus glabra) leaf backlit by the sun. Wych elm is the only elm that is undisputedly native to Britain.

A cluster of unripe wych elm samaras (a type of winged fruit). Each samara has a seed centred between two symmetrical wings.

These leaves belong to a field maple (Acer campestre), another tree native to Britain. They always make me think of extra-large hawthorn leaves.

Bluebells are a classic British wildflower, the kind of plant that almost everyone can recognise. But there isn’t just one species in Britain anymore; there are two species and a hybrid. Our native bluebell is the common or English bluebell (Hyacinthoides non-scripta), but there is an alien species about too: the Spanish bluebell (Hyacinthoides hispanica), popular with gardeners and introduced around 1680. Both species hybridise to give the hybrid bluebell (Hyacinthoides x massartiana a.k.a. Hyacinthoides hispanica x non-scripta) which was first noticed growing wild in 1963. The genetics of our native bluebell are therefore threatened by dilution, and a lot of ecologists aren’t happy about that at all. According to Plantlife International, a recent study conducted by their volunteers found one in six British broadleaved woodlands surveyed contained hybrid or Spanish bluebells.

I think that these are hybrid bluebells. Why? Our native species have their bells all on one side of the stem, which droops over with the concentrated weight. Spanish bluebells have a thicker, straight stem with bells all around. The hybrid has bells around a slightly drooping stem - which is an accurate description of the bluebells in this photo.

In case you missed it, here is a link to Part 1 of this four-part series of posts. And here is a link to Bluebells for Britain: A report on the 2003 Bluebells for Britain survey, a leaflet in .pdf format by Plantlife that sheds more light on the subject and gives some simple advice to gardeners.


Posted in Gone for a walk





Flowers of the ash, the wild cherry, and the sycamore

Spring is in the air and flowers are everywhere. So far this year treeblog has carried posts on the flowers of the hazel, the alder, the larch, and the goat willow; also last week, a crab apple on the verge of flowering; and if I may whet your appetite for posts to come, have a sniff of these soon-to-be-flowering trees: the rowan, the horse chestnut, the birch, and the hawthorn. What a bounty! What a feast! In today’s post: the flowers of the ash, the wild cherry, and the sycamore.

Cherry blossom.

The wild cherry or gean (Prunus avium) is a spectacular sight at this time of year as whole trees are covered with white flowers - the magnificent cherry blossom. All wild cherry flowers are hermaphrodite, each flower having a single style (♀) surrounded by several stamens with orange anthers (♂). By mid-summer, the bee-pollinated flowers will have developed into small red then red-black fruits; they are eaten by birds.

Cherry blossom at sunset.

These three wild cherry photos were taken yesterday evening in the Ewden Valley.

Ash flowers.

On the flowering front, the wind-pollinated ash (Fraxinus excelsior) is a bewildering, polygamous mess. From my Trees of Britain & Northern Europe (Mitchell, 1974):

Total sexual confusion: some trees all male, some all female, some male with one or more female branches, some vice versa, some branches male one year, female the next, some with perfect [hermaphrodite] flowers. Male flowers in dense globular bunches along shoots of previous year, purplish then dark red in bud, open yellow with slender anthers in early April well before leaf-buds; female flowers similar but open more widely into a filigree of purple then pale green.

and from my Trees of Britain & Europe (Aas & Reidmiller, 1994):

Flowers: Apr-May, before the leaves open, trees may be monoecious or dioecious, and the flowers hermaphrodite or unisexual, arranged in many-flowered panicles, at first upright, but later drooping, at the tips of the previous year’s growth. Individual flowers are inconspicuous and lack petals [and sepals]. Stamens 2(3), are brownish-red to violet; ovary has 2-lobed stigma.

Ash flowers.

I’m having difficulty discerning whether the ash flowers in my photos are male, female, or perfect, a problem possibly compounded by the flowers perhaps being past their best. With help from this this excellent page by Eva Wallander, I’m fairly sure the pinkish-red-headed parts are anthers (♂), but I’m not at all sure whether the black-headed parts are stigmas (♀) or just anthers that have already lost their pollen. If you can help me out, please email or leave a comment.

These three ash photos were taken on Friday.

Sycamore flowers seen yesterday on a tree in the Ewden Valley. Most local sycamores hereabouts are a little behind it with their inflorescences.

Figuring out which parts of a sycamore inflorescence are male and which are female sounds like another pain in the ass! From a paper by Binggeli (1990):

In Sycamore, Acer pseudoplatanus L., all flowers are functionally unisexual and appear sequentially on a single inflorescence… In a single inflorescence the sex of sequentially opening flowers may differ more than once in time, and de Jong… described eleven different modes of sex expression within an inflorescence…

and from Rusanen & Myking (2003):

The reproductive system is complex. The majority of flowers are morphologically hermaphrodite, but all flowers are functionally unisexual. In each inflorescence there are both male and female flowers – but the number of male flowers is higher, and the duration of the male flowering sequence is always much longer than that of the female sequence. At the tree level, half of the individuals function predominantly as male or female, but there may be some annual variation in sex expression. Flowers are a vital source of pollen and nectar for bees and bumble bees, which are the primary vectors for pollination. A small proportion of the flowers are also pollinated by the wind.

Sycamore leaves illuminated against the sky yesterday afternoon.


References

Aas, G. and Riedmiller, A. Translated by Walters, M. (1994). Trees of Britain & Europe. HarperCollins Publishers. – A Collins Nature Guide.

Binggeli, P. (1990). Detection of protandry and protogyny in Sycamore (Acer pseudoplatanus L.) from infructescences. Watsonia, 18, 17-20.

Mitchell, A. (1974). Trees of Britain & Northern Europe. HarperCollinsPublishers. – A Collins Field Guide.

Rusanen, M. and Myking, T. (2003). EUFORGEN Technical Guidelines for genetic conservation and use for sycamore (Acer pseudoplatanus). International Plant Genetic Resources [Rome]. Available from: http://www.ipgri.cgiar.org/publications/pdf/853.pdf [Accessed 26th April 2009].


Posted in Dendrology





Young sycamore leaves

Tree leaves: are there any so inherently beautiful as a sunlit young sycamore leaf? I resent Acer pseudoplatanus, a British non-native, for being naturalised across the whole country; but those luscious young leaves, goldenly illuminated by the sun; how appealing a token of spring!


Posted in Gone for a walk





Photos from a walk down Ewden (21st February 2009): Part One

My legs took me on a wee walk down Ewden valley the other day... I found a tunnel in the woods.

This young holly tree (Ilex aquifolium) looked beautiful bathed in the late afternoon sun, but unfortunately this photo doesn’t do it justice! And I don’t know whether it was this particular holly, or if I’ve just never noticed before, but the butter-coloured leaf margins were quite striking.

The vigorous-looking leading shoots of the same holly.

Three hawthorns (Crataegus monogyna) provide the backdrop for this barb. The hawthorns have spikes too.

A weird little twig sticking out of a sycamore (Acer pseudoplatanus) trunk. When this tree gets older the smooth bark will turn platey and flaky-looking, like this.

A tiny-weeny twig sticking out of the same sycamore. I think you can see it in the top left of the previous photo.

A reflection of sycamore and ash (Fraxinus excelsior) trees. Not in the Ewden valley, this one! Can you guess what is doing the reflecting?


Posted in Gone for a walk





Five favourite photos from 2007

As 2008 draws to a close, I thought it would be nice to look back on some of my favourite photos of the year. Then I realised that I never did this for 2007, so perhaps I ought to cover that year first, and look back on 2008 next week. This is good time to mention that I have been going through the archives and replacing a lot of the old lo-res (500px by 375px) images with higher resolution copies (1024px by 768px). To view the full-size versions, just click on the photo to be taken to its Flickr photo page, and then click on the ALL SIZES button (above the top left-hand corner of the photo).

To be included on this most exclusive of lists, each photograph had to satisfy the criteria of 1) having been taken by myself during 2007 and 2) subsequently featuring on treeblog while 3) being one of my stand-out faves. I limited myself to just five, and I had a hard job on narrowing it down. But here they, are in chronological order!

3rd May 2007 Yes, this photo did feature in the previous post (an unfortunate coincidence), but it originally featured in a post entitled ‘Blackford Hill gallivanting’. It was a sunny day at the end of my third year at Edinburgh when I photographed these new sycamore (Acer pseudoplatanus) leaves on a walk up Blackford Hill, which was my territory of choice back then as I lived so close by. I love how the sun highlights every detail of the tender young leaves.

16th June 2007 I took this photograph on a visit to Derwent Reservoir - the towers of the stunning dam wall are seen in the background. I love how the sunlight catches some of the hawthorn leaves.

16th August 2007 Just before I started my final year at Edinburgh, one of my classes went on a field trip to the Italian Dolomites, part of the Alps. It was a brilliant trip in every respect, and the scenery was most conducive to photography. In fact, three of these five favourite photos were taken on that trip! This photograph was taken on our first proper day, when Bruno, a local forester or park official, acted as our guide on a walk up a valley. I have never been anywhere so beautiful in all my life, and this photo is a good one in that it gives some sense of the enormity of the mountains.

24th August 2007 We visited this stunning locale twice. Another place so beautiful words or photos cannot do proper justice. I have got to go back one day, and that day can not come soon enough! The lake is called Lago di Calaita, and off this photo to the right is an old rockslide that we climbed up to reach a higher part of forest.

24th August 2007 The sky at night as photographed from our accommodation for the last three nights of the trip: two log cabins in the middle of nowhere perched halfway up a mountainside! It was really pitch black, but a long exposure brought out detail that the human eye couldn’t see. The remoteness from any kind of built-up area meant that the stars were very prominent, lending the sky a quality I haven’t been able to see in Britain. This photo featured in a post entitled Field trip to the Italian Alps (Part One). The previous couple featured in Part Two.

It’s funny how three of those five photos came in the space of eight days in the Dolomites. It might be something to do with associating the positive memories of the field trip with the photographs. No winter photos made it onto the list. I haven’t picked out five favourites from 2008 yet, but I wonder if any wintry pix will make it into those. Regardless, I can’t see the list being dominated by one trip!


Posted in Miscellany





Sycamore in Britain: native or non-native?

Sunny young sycamore leaves from a walk up Blackford Hill, Edinburgh, on the 3rd of May 2007.

Sycamore (Acer pseudoplatanus L.) is a large deciduous tree common throughout the British Isles. It may be known in Scotland as the plane. Foreign readers of this blog should not confuse the British sycamore, with which I am concerned, with different species growing around the world which are also commonly called sycamore or plane.

The popular view is that sycamore is not a native of Britain. However, I recently read an article from a 1987 issue of the Quarterly Journal of Forestry by Esmond Harris 1, who puts forward a case for sycamore being a British native.

Harris begins with a little digression. The English used to call sycamore “the great maple” or the “mock plane tree”, and in fact the taxonomic name means maple (Acer) masquerading (pseudo) as a plane (platanus), as sycamore leaves are similar to those of planes such as the London plane (Platanus x hispanica) and the Oriental plane (Platanus orientalis). Harris writes that the modern common name “seems to have come from monks returning to Europe who saw its similarity to “sycomorus” of the Bible which is the sycamore fig (Figus sycomorus) of the Middle East”.

Back on the topic of sycamore’s provenance, Harris states the popular view is the tree was introduced to Britain by the Romans, but disputes this by arguing that there is no evidence for this “and anyway, why should they introduce a tree for which they would have no apparent use?” The Romans are known to have introduced useful trees, such as the sweet chestnut (Castanea sativa), which was grown for its nuts.

Harris dismisses the theory that sycamore was introduced from France in the Middle Ages on the grounds that, even though many writers have referred to this, none provided any evidence. Sycamore’s natural distribution in France does not reach the English Channel, a fact, Harris writes, used to support the non-native theory. Further support for this theory comes from the lack of sycamore pollen in ancient deposits, although Harris argues that sycamore pollen being gelatinous, it “could not be expected to preserve well” compared with “the hard pollen grain of most trees and shrubs”.

“However, with no positive evidence for introduction” Harris writes, “my own view is that sycamore may well be a native because it grows so well all over Britain, even in the most inhospitable places, and regenerates so freely.” I think this is a rather shaky foundation on which to base a theory of British nativity, for there are known introduced species that grow well and regenerate freely all over Britain (e.g. Rhododendron ponticum) while there are also known British natives that are confined to certain localities or habitats (e.g. wild service tree, Sorbus torminalis).

Harris provides examples of references to sycamore from the Middle Ages: a fourteenth century carving of a sycamore leaf in St. Frideswide’s shrine in Christchurch, Oxford; a written record in Turner’s Herbal in 1551; and a mention by Chaucer in Canterbury Tales, written about 1380, who was once a forester. But if sycamore was introduced by the Romans or during the Middle Ages, then why shouldn’t it appear in carvings or books from this time?

The next piece of evidence Harris uses to try to support his theory is also rather flimsy. “Unfortunately the wood of sycamore is so like maple that it cannot easily be distinguished in old wooden artefacts, furniture and musical instruments, where it is usually referred to as maple anyway. However the native field maple [Acer campestre] is too small to have been a significant timber tree.” Actually field maple can reach a height of 25 m (~80 ft) and a girth (circumference) of 3 m (~10 ft) at breast height 2. According to Wikipedia, Rushforth’s Trees of Britain and Europe 3 describes field maple wood as hard and strong and used for furniture and flooring.

Harris’ case for sycamore being native to Britain ends with a whimper. “The question needs to be asked, “what is the positive evidence that sycamore is an exotic in Britain?” After all, it is the only supposed non-native for which there is no evidence of introduction. We know how all the other introduced trees came here.” Not knowing how sycamore was introduced is no argument for saying that it wasn’t introduced! The rest of the article is rather interesting and goes on to describe the growth of sycamore in Britain, and its usefulness in terms of timber, amenity, shelter, and biodiversity.

Harris didn’t manage to convince me that sycamore is a British native. I’m sticking with the popular view that it is an introduced species, albeit a fully naturalised one nowadays. From the Royal Forestry Society of England, Wales and Northern Ireland’s site:

[Sycamore] is not native to Britain. Its real home is high ground in southern and central Europe extending northwards to Paris and east to the Caucasus.

When and who first introduced sycamore to Britain is uncertain. It may have been the Romans but it was still scarce here in the 16th century and has only really become established over the last 200 years.

As an epilogue to Harris’s article, there was a response by M. P. Denne 4 (of the Department of Forestry and Wood Science, University College of North Wales) published in the next but one issue of the Quarterly Journal of Forestry. Denne writes that she has “not yet found any sycamore amongst the fragments of charcoal that I have been asked to identify from a number of Neolithic sites in North Wales”. The second half of her letter is a good response to Harris, so I’ll give Denne the last say in this matter.

Judging from the uses they seem to have made of the different timbers on these sites, Neolithic people must have had considerable knowledge of the wood properties of different tree species. Since sycamore can produce good quality timber on a wide variety of sites, and the wood is strong and easy to work, one would have expected it to have been in frequent use if it had been widely available at the time. As Esmond Harris points out, sycamore regenerates freely and grows well all over Britain, even on inhospitable sites. So if it was native to Britain, is there any reason why it might have been relatively rare in Neolithic times?



1 Harris, E. (1987) The Case for Sycamore. Quarterly Journal of Forestry, 81 (1), 32-36.
3 Mitchell, A. (1978). Trees of Britain & Northern Europe. Collins Field Guide, HarperCollinsPublishers.
4 Rushforth, K. (1999). Trees of Britain and Europe. Collins.
5 Denne, M. P. (1987). Is Sycamore Native to Britain? (Correspondence). Quarterly Journal of Forestry, 81 (2), 201.


Posted in Miscellany





Photos from a field trip in Ormsary (September 2007)

I was on a field trip for a week at the beginning of September. A bunch of ecological science final year students in a cluster of chalets and a palace-like bungalow near Ormsary, Kintyre, Scotland. Galls, silver birch provenance trials, etc.

oak

Oak overhead! (Photo taken on the 2nd of September 2007).

sample plot in oak woodland

Standing in a sample plot in oak (probably sessile) woodland. Check out all the bracken! The red and white thing is a two metre tall ranging pole and marks one corner of the square plot. (Photo taken on the 2nd of September 2007).

tar spots on sycamore leaves

Tar spots on sycamore leaves. Tar spots are caused by the fungus Rhytisma acerinum and don't really harm the host tree, apart from reducing the photosynthetic area of the host's leaves. (Photo taken on the 3rd of September 2007).

larch and a pine

Larch and a pine at the edge of a grassy area. (Photo taken on the 3rd of September 2007).

mushroom cloud

An interesting cloud. Mushrooms, anyone? (Photo taken on the 3rd of September 2007).


Posted in Holidays and field trips





Red Rose (27th July 2007)

plane tree in Red Rose 'fun pub', Marmaris, Turkey (27th July 2007)

A plane tree at sunset in Red Rose 'fun pub', Marmaris, Turkey.


Posted in Holidays and field trips





The Plane Tree of Hippocrates

the Plane Tree of Hippocrates (June 26th 2006)

On the Greek island of Kos, an ancient plane tree occupies Platanou Square in the capital, Kos Town. Located close to the harbour and the Castle of the Knights, it is under this plane tree that Hippocrates, oft regarded as the 'Father of Medicine', is according to legend said to have taught many of his students some 2400 years ago. Another legend tells of St Paul the Apostle standing beneath the plane tree, speaking to the inhabitants of Kos and spreading the word of Christianity. According to Wikipedia its crown has a diameter of about 12 metres, which is currently supported by a cage of green-painted metal.

the Plane Tree of Hippocrates (June 26th 2006)

Contrary to the legends, the current tree is almost certainly not as old as they require. Yet it is likely that this tree is a descendant of the original tree, or perhaps a new tree that grew from the still-living roots of the original tree once its above-ground parts had expired. Thomas Pakenham, in his Remarkable Trees of the World (2002, Weidenfield & Nicolson), writes:

For centuries people have believed that this is the tree under which the great healer sat when he taught medicine to his disciples in the 5th century BC. I would like nothing more than to share their faith. [...] But kill-joys will point out that the wood of the oriental plane tree, Platanus orientalis, rots relatively quickly. Today the main trunk is a hollow shell like an old gourd. True, there are large branches growing out of the cage from the east side of the gourd; and there is a new trunk, layered from a branch on the west side about a century ago, now forming a delightful dome of young branches. But I doubt whether the original tree, whose trunk is now a shell, is older than 600 or 700 years.

But wait, say the fans of the great healer. Suppose there was a plane tree there in Hippocrates' day. Of course, it didn't live 2500 years. But its roots did. [...] The trunk, this old gourd, may be the fourth generation of the great healer's trees sprung from the roots.

the Plane Tree of Hippocrates (August 3rd 2004)

I have visited the Plane Tree of Hippocrates twice; in August 2004 and again in June 2006. I must confess to being disappointed upon first seeing it, after hearing rumours of this legendary, ancient tree. But after visiting it for a second time, I could imagine its true size, as if its hollow trunk was still solid and whole.

the Plane Tree of Hippocrates (August 3rd 2004)


Posted in Notable trees + Holidays and field trips





Blackford Hill gallivanting (3rd May 2007)

young sycamore leaves

Sycamore (Acer pseudoplatanus) - flower and new leaves.

young sycamore leaves - backlit

Young sycamore leaves backlit by the Sun.

early elder inflorescence

Early elder (a.k.a. elderberry) (Sambucus nigra) inflorescence.

young sycamore leaves

The young leaves of a small sycamore which was decapitated when a patch of gorse was cleared. The sycamore is a lot quicker off the mark in terms of recovery, by the look of things.

gorse shieldbug

The gorse shieldbug (Piezodorus lituratus). Tenuous tree link: feeds on gorse, which is almost a tree. A wannabe tree.


Posted in Gone for a walk





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