treeblog - All posts tagged: sycamore

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.

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.

treeblog update (Set A, Day 1102): cider gums. Set C(r) rowans are sprouting!

On parade today are all fifteen Set A cider gums, lined up and ready to be inspected for the first time since August! These poor young eucalypts have been ravaged by the harshest winter for many a year, and it looks as though six of our comrades have fallen (and most of the survivors have frost-damaged tips) – yet there may be still be hope. The previous winter (2008-2009) looked to have dealt fatal blows to cider gums Nos. 3 and 15, but they somehow managed to crawl back from the precipice of the grave. Hardy buggers. Can this miracle be repeated in 2010? (Photographs taken yesterday, 1102 days since I planted Set A.)

Cider gum No. 3 - one of the three Class III runty gums. The dead upper part of No. 3 was killed off by the previous winter, but the winter-just-gone looks to have put paid to its recovery efforts.

Cider gum No. 7 – the tallest of all the cider gums. A real Class I über-gum. It now shares its pot with a brassy young sycamore (Acer pseudoplatanus) that has recently sprouted.

Cider gum No. 13 – the only treeblog tree still on crutches. Some of the other gums are looking a bit leany or loose in the soil, so support canes will probably be making a comeback.

Cider gum No. 15 - Class III. Has this winter managed what the previous one couldn’t? Poor things looks dead as a door-post.

Set C news: There are Set C(r) rowans sprouting by the bucketload! These beauties will be the subject of the next post, but I’ll tell you right here and now that yesterday I counted thirty-three seedlings in the Whitwell Moor section and two in the Upper Midhope section. I photographed them this afternoon, along with the Set C birches, which are just beginning to put out their first leaves of the new year. treeblog is in a good place!

Fairholmes – Derwent & Howden Reservoirs – Alport Castles – Fairholmes (13th February 2010)

The imposing Derwent Dam. When the reservoir is full, as it was on Saturday, water pours from between the two towers to cascade foamily down the mighty stone wall.

A spot of super weather was forecast for Saturday so in the morning I headed off to Fairholmes, the visitor hub for the Derwent Valley. The weather didn’t live up to my high expectations, but it wasn’t too bad. At least it’s spring now; winter seems to have been abruptly switched off on the 28th of Feb. From Fairholmes I headed north along the western shores of Derwent and Howden reservoirs, before turning west and climbing up onto the moors to reach the spectacular Alport Castles. Following the high ground south-east, I eventually ended up back at Fairholmes. (Have a go at sussing it out on Google Maps!)

Horse chestnut (Aesculus hippocastanum) buds are amazingly sticky. This one has glued itself to a few stray conifer needles.

This brave young alder (Alnus glutinosa) was growing part-submerged in the reservoir.

The road running up the side of the reservoir is bordered for a few hundred metres by a hawthorn hedge. It has been recently savaged along most of its length, probably by rabbits. They have stripped the bark from most of the stems an inch or less in diameter; anything larger was left unharmed.

Illuminated fruticose lichens (and unilluminated foliose lichens) growing on sycamore (Acer pseudoplatanus) bark on the site of Tin Town. (For the fascinating history of Tin Town, or Birchinlee, see here and here.)

A fine beech (Fagus sylvatica) growing on the site of Tin Town – so it can’t be any older than a hundred years.

This is another beech, but instead of having the lovely, smooth, silver bark typical of its species, this tree was all over disfigured by cankers.

This is the tip of the westwards-pointing spur of Howden Reservoir where it is joined by the River Westend – and look! There is still ice on the surface in the middle of March!

Looking back at Howden, having attained the lofty heights of the moors. There were still plenty of snow pockets around up on the tops. It hasn’t snowed for weeks!

Almost back at Fairholmes – this is the view across the northern tip of Ladybower Reservoir.

Next month’s edition of the Festival of the Trees will be hosted by Vanessa of Vannessa’s Trees and Shrubs Blog. Send in your submissions to treesandshrubs [dot] guide [at] about [dot] com. The deadline is the 29th of March. (The optional theme, in honour of April’s Fools Day, is humourous trees.)

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.

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.

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”.

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 - 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 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 - 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.

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.

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 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?

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 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).]

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.

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.

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.

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

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.

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.

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.

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].

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!

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.

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?

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!

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 a forester himself at one time” ². 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 ³. According to Wikipedia, Rushforth’s Trees of Britain and Europe ⁴ 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 ⁵ (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.
² According to Wikipedia, “on 22 June, [Chaucer] began as deputy forester in the royal forest of North Petherton, Somerset”.
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.

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.

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

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

Blackford Hill gallivanting (3rd May 2007)

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.

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

Tricotyledonous sycamore: first true leaves

Below is a photo of my tricotyledonous sycamore (taken by my father on Saturday), 23 days after I discovered it. Its first true leaves are now developing, and I am glad to see that there are three of them. As the tree develops, growth (branches, leaves and so on) will be trifurcate (in threes), as opposed to normal dichotomous (in twos) growth. Basically, this tricotyledonous sycamore is to a normal dicotyledonous sycamore what a four-leafed clover is to a normal three-leaved clover (Trifolium repens). I am interested to see whether or not its offspring will be tricotyledonous, although it's going to be quite a wait to find out.

Tricotyledonous sycamore!

Aaah, the humble cotyledon. The Oxford Dictionary of Biology defines ‘cotyledon’ thus:

A part of the embryo in a seed plant. The number of cotyledons is an important feature in classifying plants. Among the flowering plants, the class known as Monocotyledoneae have a single cotyledon and Dicotyledoneae have two. Conifers have either two cotyledons, as in Taxus (yews), or five to ten, as in Pinus (pines). In seeds without an endosperm [*], e.g. garden pea and broad bean, the cotyledons store food, which is used in germination. In seeds showing epigeal germination e.g. runner bean, they emerge above the soil surface and become the first photosynthetic leaves.

[* The endosperm is a nutritive tissue that surrounds the developing embryo in a seed.]

The sycamore (Acer pseudoplatanus) is a non-native yet extremely common tree in Britain. It is dicotyledonous and undergoes epigeal germination.

Out walking on the 5th of April, I spied a sycamore seedling with three cotyledons. An amazing mutant tricot! This is the second time I have seen one of these; the first was on a field trip in spring 2005. Back then I was amazed by my lucky find. Although I took it home with me, it rapidly perished due to a long day in the field with no suitable way to preserve it. Back to the 5th of April… This particular day I was walking down a country lane with my friend, and noticing all of the newly germinated seedlings in the edge of the road, I was reminded of my encounter with the tricot. From time to time I would glance into the edge looking for another – and as luck would have it, I found one! I wasn’t taking any chances with this one, so I left it in situ, returning later in the day to collect it. Behold!

Hermitage of Braid (6th March 2007) ii

More photos from my Wednesday wander in the Hermitage of Braid. Monochrome!

First up: a stand of trees on a small mound. Some beech and a huge sycamore in there, so I remember. A lot of storm damage though, with plenty of deadwood on the ground and a couple of dead trunks.

This next photo is a closeup of a nicely decomposing dead standing trunk. Check out the little holes made by woodworm or perhaps some kind of bark beetles.

This tall and skinny tree looked like a sycamore. I'm not totally certain it was though - I can't ever remember seeing one so gaunt. But with this being in the bottom of a narrow valley, it would have had to grow tall out of necessity.

Finally, I have a photograph of a fallen branch in the Braid Burn (a burn is the Scots word for a stream or small river).

Hermitage of Braid (6th March 2007)

Yesterday I took a walk in the Hermitage of Braid, a small valley woodland area in Edinburgh. The trees are mainly broadleaved species, and there are quite a few big old specimens. Take the following, for example:

Unfortunately, I didn't pay too much attention to what flavour tree it was. From the photograph the branches look beechey but judging by the bark I'd say this is probably some kind of lime (Tilia) or maybe an oak.

The next photograph shows another tree of the same species with an impressive wound. There was a fair bit of wind damage like this in the Hermitage.

Even with all the deciduous trees still devoid of leaves, this little sycamore seedling growing on a burn-side rock appeared like a symbol of the impending spring.

The beech buds in the next picture might remain closed for another month or so yet. Bring on the summer!

sycamore

Spring and decay (24th April 2010)

treeblog update (Set A, Day 1102): cider gums. Set C(r) rowans are sprouting!

Fairholmes – Derwent & Howden Reservoirs – Alport Castles – Fairholmes (13th February 2010)

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

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

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

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

Young sycamore leaves

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

Five favourite photos from 2007

Sycamore in Britain: native or non-native?

Photos from a field trip in Ormsary (September 2007)

Blackford Hill gallivanting (3rd May 2007)

Tricotyledonous sycamore: first true leaves

Tricotyledonous sycamore!

Hermitage of Braid (6th March 2007) ii

Hermitage of Braid (6th March 2007)

sycamore

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