Elms of the Essex/Cambridgeshire border

In his book “Elm”, H.R.Richens wrote: “Essex is holy ground for the elm systematist. Nowhere else in England, nowhere else in Europe, is so complex an assemblage of elms to be found”.

This gallery features some of the remaining Ulmus minor (Field Elms) in just one of the Essex hybridisation zones. In fact it lies on the county’s border with Cambridgeshire and Suffolk, broadly straddling the A604 which runs south west from Cambridge towards Colchester.

Although elm disease is currently rife within this area, and has done immense damage in the last year or two, certain distinctive strains of elm seem largely to be avoiding it. Without proper testing, it is impossible to say whether this is the result of chance or of actual resistance. However, it does seem reasonable to propose that if significant resistance is to be found in Field Elms, it is most likely to be encountered within the most complex gene pools.

All photographs were taken in July 2014.

  Bartlow1 – The southernmost of a line of three mature trees on Dean Road north of Bartlow. In the centre of the tree a patch of leafless twigs  is just visible. In 2008 this patch showed symptoms consistent with elm disease. Whatever the true cause, the symptoms did not spread.

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  Bartlow2 – The middle tree.

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  Bartlow3 – The northernmost tree.

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  Bartlow4 – The three Bartlow trees seen from the north west. In July 2014 all three were completely free of current disease symptoms.

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  Bartlow5 – The base of one of the Bartlow trees. Compare with the bark of the Haverhill trees below.

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  Bartlow6 -All three trees appear once to have been pollarded, and have therefore made lower and more spreading growth than would  otherwise have been the case.

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  Bartlow7 – Suckers opposite the line of trees. It is usual for vigorous growth of this type to be far more vulnerable to infection than the slow- growing twigs of mature trees.

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  Bartlow8 – Sadly, and despite first impressions, there is wilting in the sucker growth. It can be assumed to be elm disease. The crucial  question is whether it will develop as rapidly as in other strains of U. minor, or to some extent be contained.

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  Bartlow9 – Foliage of the Bartlow trees. Leaves are small, leathery, slightly glossy, and Lammas growth is common. All these features strongly  distinguish this strain of U. minor from others in the locality.

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  Bartlow10 – The underside of the same spray of leaves. Galls (as visible here) seem endemic around Bartlow, but were not seen elsewhere.

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  Linton1 – A small elm between Bartlow and Linton. It is neither very impressive nor attractive, but the fact is that it and all its associated  sucker growth is completely free of disease.

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 Linton2 – Foliage of the same tree, strongly distinct from that of the three trees on Dean Road.

 

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  Linton3 – Another fairly small but mature elm at Cardinal’s Green, near Linton. Its growth appears rather pendulous. Unfortunately there are  signs of elm disease in a smaller tree apparently of the same strain.

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  Haverhill1 – A line of some eight Field Elms in the centre of Haverhill, one of them about 110 feet high (all the others were topped). All but  one were fairly healthy until 2014, but disease is now all too apparent. In the case of the tallest tree, there are signs of root infection from an adjacent tree which had died outright but been left in situ.

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  Haverhill2 – The base of the largest Haverhill tree. Parts of the crown remain healthy, so the wilting of epicormic shoots so far down the trunk  suggests disease spread by root infection. With regard to the bark, compare that of the Bartlow trees above.

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  Haverhill3 – South of Haverhill; different in form and leaf from other elms in the locality.

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  Haverhill4 – Leaf of the tree above.

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  Granta1 – Leaves from a large elm (c.60 foot) overhanging the River Granta at Granta Park. The leaf shape suggests U. minor x U. glabra,  but is distinct from the two standard notomorphs of that crossing – namely x hollandica (Dutch Elm) and x vegeta (Huntingdon Elm). The tree grows in an area of wet woodland in which five or more strains of elm can be identified, including some intermediate forms.   The only plausible explanation is that hybridisation has occurred at this site.

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  Granta2 – Part of a larger area of young and semi-mature trees beside the lawn at Abington Hall, Granta Park. Given that disease is rife on  the borders of the park, signs of it would fully be expected in a stand of this size, but there are none.

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  Granta3 – Two of the larger stems at Abington Hall, showing a manner of growth rather unlike native elm. One wonders whether there has  been hybridisation involving exotic elm at Abington, once famous for its planted trees. Some ingress of U. macrocarpa is thought possibly to have occurred at Vicary Gibbs’ Aldenham estate; something similar may have happened here.

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  Granta4 – The interior of the canopy at Abington Hall; the sinuous branching and relatively sparse foliage (neither feature is apparent from  outside the stand) seem little related to U. minor.

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  Granta5 – A spray of leaves from the Abington Hall trees. Notable features are the extreme basal asymmetry, dark hue, semi gloss, twisted  acuminate tips and finely formed serration. Insect attack is significantly less than occurs locally in hedgerow trees (compare the leaves from Linton, above).

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 Granta6 – A single leaf from the spray above, showing the base of the long side of the leaf curving to overlap its petiole.