7 posts tagged with

Prunus - the cherries

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Forest forensics

You might not notice anything special about this scene at first glance, but something caught my eye as I drove past. I noticed that a branch had come down, although upon closer inspection that wasn’t everything…

Here’s how I think it happened:

This pine (not a Scots pine, Pinus sylvestris – its needles were too long) had fallen (blown?) over…

…and smashed into a roadside horse chestnut (Aesculus hippocastanum), breaking off half of the tree at a weak union between co-dominant stems with included bark. The resulting nasty wound can be seen in the top-right of the photo; the guilty pine is in the bottom-left.

The half of the chestnut that snapped out fell across the road and hit a tall wild cherry (Prunus avium), breaking a couple of high-up branches.

After hitting the horse chestnut, the pine tree carried on falling across the road. Here is the top section lying on the other side of the road; the middle section that would have blocked the road has been removed.

The pine struck a second horse chestnut on the far side of the road to the first, smashing through a few branches (the lowest in the photograph was probably substantial enough to have been called a co-dominant stem).

I took this photo sat atop the top section of the pine, looking across the road to the pine’s stump and the first chestnut that it damaged. The large wound where the chestnut used to fork can be seen maybe fifteen feet up the stem.

This carnage occurred sometime between Sunday afternoon and Tuesday afternoon. Obviously somebody has been out to clear away the fallen branches and reopen the road, but no attempt has been made to clean up the wounds. The first of the horse chestnuts really wants felling because of the danger it poses to users of the road.

By coincidence, all of this happened just a few metres away from where I was photographing fungal fruiting bodies on a cherry tree on Sunday afternoon – the subject of the previous post in fact! According to its name-tag, that cherry tree was No. 0852. The trees in this post were tagged as 0855, 0856 and 0858 – the cherry, first chestnut mentioned and second chestnut mentioned respectively (I couldn’t see a tag on the pine). Isn’t that funny?

So just to recap how I pieced together the sequence of destruction, I’ve scribbled all over the first photo at the top of this post. The blue hoops ring the leaning pine stump (right of the road) and its detached, recumbent upper section (left of the road). As it fell it struck horse chestnut No. 0856 (red) and horse chestnut No. 0858 (orange). Half of chestnut 0856 was broken off and fell across the road, striking wild cherry No. 0855 (pink). The resulting wounds of 0855, 0856 and 0858 are all circled. Carnage!

Posted in Miscellany

Chicken of the woods?

About five weeks ago I was driving along the bottom of the Ewden Valley when I caught sight of a big bracket fungus growing eight or nine feet up the trunk of a wild cherry or gean (Prunus avium). I returned later in the week with my camera, but as the fungus was a few feet above my head and it was quite dark under the canopy of trees my photos didn’t turn out very good. I intended to come back with a step-ladder and take some better pictures but for whatever reason I didn’t get back again until yesterday. Over the last month the fungus has degraded somewhat. It’s sadly no longer the fresh specimen it was at the end of May. It has a not-unpleasant, cheesy sort of smell to it. The big brackets were more or less a foot wide.

A month ago the fungus was quite yellow (at least it was below, which was all I could see of it), and my first thought was that it was chicken of the woods (Laetiporus sulphureus). I still think this may be the case, but I’m not so sure. When am I ever sure? Maybe it’s something like Inonotus cuticularis? Listen - dear reader, if you are able to shed any light on this matter I would greatly appreciate it! (Just bear in mind that the fungus is past its best and is starting to look a bit ropey.)

This is the best of the photos I took when I first discovered the fungus five weeks ago.

This is the host tree: one very tall cherry. Its lower branches are dead, but it’s uppermost branches are still leafy. There is a big, old wound on the stem just below the fungus, and the fungus itself grows from an old wound. A shiny new tag identifies it as ‘0852’. 0852 isn’t a brill tree.

Is this weird? It’s a little weird, right?

Posted in Pests and diseases

One big Ganoderma bracket

Ganoderma sp. bracket at the base of a small cherry (Prunus sp.) tree, not a million miles from York. Seen yesterday - the 24th of September.

This Ganoderma sp. is a saprophytic fungus: it will only attack the “non-living” heartwood and won’t harm the “living” sapwood. Infected trees may appear normally healthy in external appearance, but inside they can be a soft and mushy mess liable to collapse or fall over at any time. In my new job as an apprentice arborist I’ve already seen a few examples of cherries with healthy canopies, but with Gandoderma fruiting bodies (the brackets) growing from the roots or base of the trunk. These roadside trees had to be felled in the interests of public safety, and I’ve seen from the stumps how rotten the infected heartwood becomes: far too soft to provide the tree with any kind of structural support.

Zounds! Some good egg has stuck his hand in the frame for scale!

One small cherry, one large bracket. If you can’t find it yourself, it’s at ground level right at the base of the tree trunk.

Posted in Pests and diseases

A walk in the sun (Part 1): over Whitwell Moor

Last Monday (the 1st of June), in the middle of a period of brilliant weather, I went for a walk up Whitwell Moor, down into Ewden, through Millstones Wood, then back down Whitwell Moor. The sun was shining, the birds were singing, the trees were rustling…and I enjoyed every minute!

The branches of an ash (Fraxinus excelsior) hang low over an abundance of flowering cow parsley (Anthriscus sylvestris).

A cherry sapling (Prunus avium) growing amongst more cow parsley by the side of a lane.

The view to the west across Whitwell Moor from the Set C(r) parent rowan (right). The lush ground cover in the foreground is bilberry (Vaccinium myrtillus).

Looking across the Moor - studded with naturally regenerating birch – to Emley Moor Mast. The mast is a Grade II Listed Building and the tallest freestanding structure in the UK at 330.4 metres. It may look as if it stands on top of the hill in the photograph but it is actually much further away, standing roughly ten miles distant.

Male Scots pine (Pinus sylvestris) flowers.

English oak (Quercus robur) leaves in the sun.

Standing amidst the heather and bilberry, Whitwell Moor’s most iconic oak: the Lonely Oak (also an English or pedunculate oak).

A developing European larch (Larix decidua) cone. Remember all those photos of larch roses on treeblog in March? This is what they have grown into!

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The 36th edition of the Festival of the Trees is up at Roundrock Journal - go check it out.

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

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.


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

Wild cherry and gorse (30th April 2007)

wild cherry flowers

Wild cherry (a.k.a. gean) (Prunus avium) flowers in the garden.

wild cherry in blossom

Wild cherry blossom.

gorse with Arthur's Seat in background

Gorse in flower, with Arthur's Seat in the background.

Posted in Gone for a walk

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