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Elm trees in Eastern Herefordshire David Taft
Elm trees especially Wych Elms in Eastern Herefordshire
- David Taft
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As this is a considerable article I am keeping it separate from my general garden musings! The Wych Elm (Ulmus glabra) and English Elm (Ulmus procera), are the two common and widespread elms found in Herefordshire, although nationally there are other species and clones. I mainly wish to discuss the Wych Elm as it occurs in local woodlands and I have several in my woodland garden. For some background context it is worth knowing that Elms in general have been afflicted with ‘Dutch Elm disease’, both here, on the continent, the North Americas, and the Antipodes. The disease is a fungus which kills the above ground part of the tree but not the roots. An outbreak of a different strain of the disease occurred on the continent about 110 years or so ago, and was researched by Dutch Scientists which is how it received its common name.
The current outbreak is due to a more virulent related fungus (Ophiostoma novo-ulmi) that was imported on Elm logs from North America in the 1960s. This problematic importation of diseased organisms was repeated again when continentally grown Ash trees were imported for woodland planting schemes, introducing the new fungal pathogen Hymenoscyphus fraxineus (initially incorrectly identified as Chalara fraxinea) into the country. I remember the death and disappearance of Elm trees in the 1960s-70s, when hedgerows were being transformed by the loss of these stately trees, often 30 metres or more in height. They regularly towered over the nearby hedgerow oaks. The local Rooks also seemed forlorn as they lost nearly all of their long-established rookeries. These hedgerow trees were English Elms and the roots remained alive in many cases, and they subsequently suckered and re-grew eventually starting to make new trees. However, as they become small trees their bark develops fissures and cracks which allow the ingress of the Large Elm Bark Beetle (Scolytus scolytus), the main vector for the spread of the fungus, and so they succumbed once more. Also acting against the recovery of these Elms is the now widespread use of mechanised hedge-cutting tractor attachments. This chops the top off the trees as soon as they poke their heads above the hedgerow, and so consigns any potential tree that may be immune to being nothing more than a hedgerow shrub and also, more often than not, prevents them from flowering. A casual look at local hedgerows will show that English Elm is still fairly plentiful, 50 or so years after it first succumbed. Authorities on trees and woodlands now generally agree that the English Elm is endemic and found nowhere on the continent except where it has been planted from imported cuttings. It is mainly found in lowland England in the southern counties and the Midlands. It is rather strange that this tree, however it arose, now spreads by suckers, as seeds are usually infertile and so not viable. But, I wanted to describe my first-hand face-to-face experience with our native Wych Elm (Ulmus glabra) which is typically a tree of woodlands rather than hedgerows. Why these two elms tend to have different habitats I do not know and I have not found a satisfactory
explanation or theory. And although this is a general rule, it is occasionally possible to find the wrong species in the apparently wrong habitat. I should mention that Elms are easily identified by their leaf shape and that if you have any doubt you only need to feel a leaf between your fingers. These two species have very coarse hairy leaves that remain hairy all summer long. The upper surface has short stiff hairs that run from the base of the leaf to the tip and make it hard to run your finger or thumb against the nap. I was demonstrating this recently in some local woods, and the audience said they could hear the rasp like sandpaper on wood. The leaves of Wych Elm are much larger than English Elm, often several times so and even more. Whereas English Elm leaves are usually oval or often nearly round with a point at the end where the central vein extends to form a drip tip; the Wych Elm leaves have their widest point nearer to the tip which looks very strange. They also often have an auricle at the base so that the leaf stalk (petiole) attaching it to the twig is virtually non-existent. Also, several of the side veins often develop drip tips, making the leaf look as if it terminates with a pair of Donkeys’ ears with a point in the centre.
The name Wych Elm is unusual, and it is believed that the word Wych is Old English in origin and referred to things that were either pliant or flexible. However, it is not clear whether this description referred to the tree and its branches or perhaps the bark and fibres; but people’s relationship with trees was formerly much more intimate and everyday and no doubt this name had some significance. Some sources say ‘wych’ derives from ‘wice’ meaning pliant or supple and refers to the bark which, for example, is still used for cordage, and lashing birch bundles used to make besoms.
The Wych Elm sets viable seed and I often find seedlings in the garden. They flower very early in the year, regularly in early March, and are pollinated by the wind. Strangely, it is reported that flowers are usually hermaphrodite, but may also be just male (stamens) or just female (pistil). However, I have not seen flowers as they are such small tassels that I overlook them, although the seeds that follow are impossible to miss. The picture on the opposite page show, on the left, the wind pollinated flower in March and, on the right, the nearly fully developed seed on the 15th April 2021. Each seed can be seen in a transparent green papery disc which will enable it to be carried away on the wind when ripe; these types of seed are known individually as samara.
Wych Elm (Ulmus glabra), showing the widest point nearest the tip Wych Elm (Ulmus glabra), showing multiple drip tips
As you can see from the picture below there is a mass of seed produced by Wych Elms, which in spring is almost as substantial as the leaves will be later in the month. A few of the darker unfurling leaves can also be seen in this picture.
It is said that Wych Elms are less susceptible to Dutch Elm Disease, but they do succumb, and the few I have in my woodland garden have died to the ground at least once in the 30 or so years I have lived here, and then re-grown from the base at ground level, not as a sucker as is usual with English Elm. However, as you can see they grow quickly and large enough to flower and set seed profusely. Seedlings are frequently found as the seed is obviously viable. The flowering tree pictured is now about 15 metres tall, and is sadly starting to die, for the second time. The process affects some branches before others, presumably indicating where the beetle has found a way in, making it a gradual death for the tree over several years. A final note on this disease; there is evidence that some trees are now resistant, and that eventually large trees will grow again. This is inferred from the pollen record which is laid down in the soil and can be analysed by using a soil auger. By aging the soil horizons and using a microscope, each species of tree can be identified by the pollen grains found therein. It shows that about 6,000 years ago Elm pollen quite suddenly disappeared from the pollen record. So, it seems this or a similar disease has afflicted Elm in the past and they subsequently recovered.
Wych Elm (Ulmus glabra) on 15th April 2021. With winged seeds & first leaves