Fruit on a Wild Service Tree close to Heartwood Forest near St Albans

Dear Readers, it’s always a joy to see a Wild Service Tree thriving, and I was astonished at the amount of berries on this specimen, seen opposite the Heartwood Café in Sandridge (the café is highly, highly recommended, especially for breakfast). I had a look at my original post, from 2015, and note that I said then that summers in the UK were rarely hot enough for Wild Service to produce a good crop of fruit. How things have changed! This tree was not shaded, and so conditions were probably ideal for berries, but I would be very interested to know if any of you have noticed an increase in berries and other fruit this year – I’ve noted before that our Rowan street trees are laden with berries, so it will be a good year for thrushes, for sure.

Now, let’s have a look at the Wild Service Tree, in all its glory, with a trip back to 2015.

Wild Service Tree (Sorbus torminalis)

Dear Readers, when I was in Cherry Tree Wood last week I made a point of popping by to visit an old friend, the Wild Service Tree that grows next to the cafe. It is so easy to overlook trees, for all their size,  and indeed I would have walked right past this if it hadn’t been pointed out to me by Brenna Boyle of Wild Capital when we were on a wildlife walk (an experience that I can heartily recommend if you want to learn about London’s plants and animals). But once identified, a Wild Service Tree  is very distinctive, with its extraordinary criss-cross bark. This one also bears a little red triangular badge, which shows that it is under a Tree Preservation Order, and so should be protected from the worst excesses of over-enthusiastic council tree surgeons.

Never common, these trees are seen as being an indicator of ancient woodland, because they rarely disperse far from their parent tree – in his magisterial book ‘Woodlands’, Oliver Rackham describes the problem. The fruits (of which more below) are probably designed to be dispersed by birds, but for hundreds of years either the wrong birds have eaten them, or the seeds are not carried away. Rackham speculates that maybe the tree co-evolved with a bird that is no longer resident in the UK, or is extinct. So, when you see a Wild Service Tree, you can be fairly happy that it’s a relative of a tree that grew very nearby.

As Cherry Tree Wood was once part of the Bishop of London’s hunting grounds (as was Coldfall Wood) it is a reminder that this spot has not always had tennis courts, a children’s playground and regularly-graffitied public toilets. The Mutton Brook is said to arise somewhere in the wood (behind the aforementioned public toilets judging by the iris-covered bog behind them), and once upon a time deer and boar were killed amongst the oaks and the hornbeams. Maybe the ancestor of this tree was there when bugles were blown and hounds scuffled amongst the fallen leaves.

The Latin species name of the Wild Service Tree, torminalis, means ‘good for colic’, and the fruits, sometimes called ‘chequers’ were used as a remedy for this affliction. More to the point, though, the fruit was used to flavour a ratafia (another new word). This is a drink made by marinating berries or fruit in some kind of spirit – think of cherry brandy or (my favourite) sloe gin. This may account for the number of English pubs called ‘The Chequers’, though some folk also think it might refer to the pattern on the bark. And there’s me thinking that these hostelries were named for an innocent board game.

The fruit of the Wild Service Tree – Photo credit below.

The fruit is said to be too astringent for today’s tastebuds, and is described as only being edible when over-ripe and allowed to become almost rotten, a process known as bletting. This is also used with wild fruits such as medlars and rowan berries. In Flora Britannica, Richard Mabey describes the taste of Wild Service berries as being:

‘…not quite like anything else that grows wild in this country, with hints of apricot, sultana, overripe damson and tamarind, and a lightly gritty texture’.

Actually, that sounds like a perfect fruit for a Christmas pudding to me. I wonder if anyone has ever tried it?

Unfortunately, summers in the UK are rarely warm enough for the Wild Service Tree to produce much fruit, and it tends to reproduce by suckers instead. However, there are exceptions: Richard Mabey describes a tree at Parsonage Farm, Udimore, in East Sussex, which has a 13-foot girth and in a good year bears two tons of berries.

Some bletted medlars – photo credit below.

The leaves of a Wild Service Tree resemble those of a maple, though they also look to me like inverted angels.

Wild Service Tree leaves (photo credit below)

In spring, the tree produces flowers which look very similar to those of my garden Whitebeam (not surprising, as they are closely related)

Wild Service Tree flowers (photo credit below)

Why, though, is this tree called the Wild Service Tree? There are a number of possibilities. One is that the word Service is a corruption of the Roman word for beer, cerevisia (which will be recognised by anyone who has ever asked for ‘dos cervesas por favor’ in a Spanish bar), and that the berries were used to flavour this beverage. Richard Mabey thinks not, however, and disputes that there is any link between this plant and beer. He believes that the word Service relates to the Old English word Syfre. And, to my delight, I discover that there is an Old English- Modern English translation site on the internet, so I put in the word Syfre. And here’s what it says:

‘clean pure chaste sober not giving way to appetite or passion abstinent temperate circumspect ‘

What a perfect description of this tree as it stands quietly alone, bedecked with white flowers or golden leaves. It seems like a serious tree to me, one not given to frivolity or nonsense, for all that its fruit has probably engendered such behaviour in generations of drinkers. I love that it is growing next to the footpath here, sinking its roots into the London clay that it prefers to all other soils. There are reminders of the history that we share with plants and animals everywhere we go.

Photo credits:

The fruit of the Wild Service Tree – “Sorbus torminalis Weinsberg 20070929 5” by Rosenzweig – Own work (own picture). Licensed under CC BY-SA 3.0 via Commons – https://commons.wikimedia.org/wiki/File:Sorbus_torminalis_Weinsberg_20070929_5.jpg#/media/File:Sorbus_torminalis_Weinsberg_20070929_5.jpg

Bletted medlars – “Mespilus germanica 01” by Takkk – Own work. Licensed under CC BY-SA 3.0 via Commons – https://commons.wikimedia.org/wiki/File:Mespilus_germanica_01.jpg#/media/File:Mespilus_germanica_01.jpg

Wild Service Leaves – “Sorbus torminalis leaves kz” by Kenraiz – Own work. Licensed under Public Domain via Commons – https://commons.wikimedia.org/wiki/File:Sorbus_torminalis_leaves_kz.jpg#/media/File:Sorbus_torminalis_leaves_kz.jpg

Wild Service Flowers by Nicolas Turland at https://www.flickr.com/photos/nturland/4697884243

All other photographs copyright Vivienne Palmer

Dear Readers, it felt very strange to wake up this morning and realise that I had actually managed to get everything done that I wanted to get done yesterday, but I didn’t have long to cogitate as we had an organised Geology walk in Coldfall Wood today. It was on the subject of geology, which for me is the unheralded crux of ecology – what underlies the soil determines so many things, from the soil organisms that will thrive to the plants that will grow, as anyone who has tried growing chalk-loving flowers in a London clay garden will tell you. The walk was led by Diana Clements, who is currently revising her book ‘Geology of London’, which is well worth a look for anyone even vaguely interested in the deep history of our area.

We looked at the main rock types in the area – London clay, Dollis Hill gravel and glacial till. Diana’s walk rather cleverly takes us through the three stages of the history of the wood as reflected in their geological history, and I for one will never look at the them in quite the same way again.

The rather unprepossessing bit of the stream above shows that the banks are London clay, and Diana had a box full of fossils found in clay, from North London molluscs, shark’s teeth, palm seeds and magnolia seeds. The clay was first laid down about 50 million years ago, when the climate was probably tropical (though the magnolia seeds may suggest at least some seasonality). Magnolias are ancient flowering plants that are pollinated by beetles, as there were no specialist pollinators about at the time.

Next it was off to the wet woodland for a look at the Dollis Hill gravel. The Thames used to run to the north of London, through the Vale of St Albans and then into the North Sea at Clacton, until it was diverted by the glaciers of the Ice Age. Some of its tributaries flowed through what’s now Coldfall Wood, depositing gravel as it went. You can find all sorts of interesting things in gravel, including quartz and the flinty Lower Greensand Chert.

The bed of the stream into the wetland area is full of gravel.

And finally, there’s the glacial till. One finger of the last glacier of the Ice Age (which retreated about 400,000 years ago) reached as far south as Coldfall Wood (and also Hornchurch in Essex for anyone who lives in those parts). As it retreated it ‘dropped’ all the rock fragments that it was carrying (to a depth of 14 metres in Finchley), and simultaneously excised deep gullies as the water in the ice sheet melted, while the surrounding soil rebounded after being compressed by the ice. No wonder the woods are so undulating, although they’re probably less so than they used to be, as the London Clay is a very soft material, easily eroded.

So, it was a fascinating walk, and I seem to have retained rather more of it than I thought I had at the time. I will certainly look at the woods in a new light!

And for those of you who read my piece on Crape Myrtle last week, I stopped to check out the bark on the tree and it is indeed both rather attractive and very smooth. What amused me no end is that having noticed one small tree, I completely failed to notice that there was another Crape Myrtle next to it. It just goes to show how distracted I’ve been, but no longer!

Crape Myrtle bark

Dear Readers, as you might remember I was in Coldfall Wood yesterday for our spider walk, and a lot of fun it was too. Well, between midday on Saturday and first thing this morning, one of the dead standing trees alongside the boardwalk has toppled over and smashed part of the bridge.

For once, it’s very unlikely that this was caused by vandalism – it’s too far from the boardwalk for someone to pull, and it’s completely surrounded by stinging nettles so it’s unlikely that someone would have waded through them to give it a push. Standing deadwood is normally pretty stable, so what could have caused the problem? I have a  theory, so here goes.

First up, the area here in Coldfall is a habitat known as wet woodland, which is extremely rare, especially in urban areas. Water runs down into the area from a variety of culverted streams, and also seeps in from the higher ground that surrounds it. In the winter the area has, in the past, been flooded to a depth higher than the handrails, and the photos below give an idea of what it’s often like in a normal and exceptionally wet winter.

A normal winter

An exceptional winter (Photo courtesy of Neville Young from 2020)

However. In recent years, there have been some attempts to improve drainage – for one thing, one of the pipes that took excess water away was forever getting blocked, so the water backed up. This was then cleared.  But I am now a little concerned that the ‘wetlands’ is getting too dry – where there used to be water mint and water bistort, there’s now a sea of stinging nettles. Clearly, you can have too much of a good thing  where drainage is concerned, because the last thing  we need is for the wet woodland area to dry up altogether.

Naturally, the amount of water in the wet woodland is to a certain extent weather-dependent (and it has been a pretty dry summer), but I have never seen it this dry in late summer.

Water mint and water plantain in the wet woodland from 2014

Water Plantain, amphibious bistort and bulrushes from 2020

Now, of course a dead tree can topple over at any old time. However, I suspect that the  the weather (hotter than usual for this time of year) and the dryness (as evidenced by the changing vegetation) are contributing and helping to destabilise the soil.  We really do need to sort out the drainage issue here, before we lose this precious and unusual habitat for good.

You can read a bit more about the different kinds of wet woodland, and its value to wildlife, here.