Worcestershire Record No. 3 November 1997 p. 4
English Elm Ulmus procera Salisbury (syn. Ulmus campestris Miller)There are three species of elm and several interspecific hybrid combinations that are either native or naturalised in Worcestershire. English Elm Ulmus procera is by far the most widespread of the three species. In spite of the ravages of Dutch Elm Disease it is probably found within most 1x1 km squares in the county. Its characteristics are that mature trees have a massive straight trunk persisting half way through the crown, the bark is deeply cracked which in maturity form square plates, there are branches at all levels which twist and ascend at the top of a dense domed crown, lower limbs become rapidly diffuse becoming short and slender. In sub-mature trees the majority of branches are ascending. The leaves are 5-9cm in length, ovate to circular with a short pointed apex; they are harshly roughened above and rough on the underside, when fully developed they are unusually curled or puckered (Mitchell 1994). The leaves are nearly always attacked by the elm leaf-gall mite Eriophytes ulmicola (Rackham 1980).
The reasons for English Elm's U. procera continued widespread distribution is that it is native to our region and was widely planted right throughout the medieval period through to the 20th century, mainly in hedgerows (Rackham 1994). Although all mature English Elm trees have succumbed to the disease it survives in hedgerows because of its ability to produce vegetative suckers. Indeed it has largely abandoned sex as a means of reproduction. Its success is further enhanced by the fact that it is invasive and over time out-competes neighbouring species - hence where English Elm U. procera is present we get dominant stretches of elm hedges and dominant stands of suckering elm in woodland (Peterken 1981), often with no other shrub species present. Rackham (1994) considers that its ability to sucker profusely may have developed over time in response to the disease which has struck in past centuries.
The status of Small-leaved Elm U minor within the county is so far undetermined. Its main centre of distribution is in the east of England which is why it is also referred to as East Anglian Elm. Small-leaved Elm U. minor is probably not native to Worcestershire with its presence being due to deliberate introduction. It is scattered along a 5 kilometre stretch of the A449 between Crossway Green and Ombersley.
The most likely candidate for a naturalised hybrid elm is the so called 'Lineage' Elm which is specifically a woodland elm (Rackham, 1980). It has an intermediate leaf shape between Small-leaved Elm U. minor and Wych Elm U. glabra, but unlike the more familiar hybrid Dutch Elm Ulmus x hollandica it is non-invasive and coppices well. Lineage Elms are often found in homogenous stands and were probably deliberately planted in most situations. This tree is known to occur in Tiddesley Wood where it is locally common and may be scattered in other ancient woodland sites in Worcestershire. Whilst in the Lineage Elm and in some of the other hybrid combinations, phenotypic features can be reasonable determined, their true parentage can probably only be resolved as and when chromosomal analysis is undertaken*
So how many fully grown elm trees remain in Worcestershire? The answer is we do not know because we have no recorded data. However, we know of the existence of several Wych Elms trees, other still await discovery. One Huntingdon Elm Ulmus x hollandica var. Vegeta is present at Barnard's Green - are there others in urban situations? Recently a mature specimen of what is probably Small-leaved Elm U. minor was seen in a hedge to the north of Bewdley.
If we can find and record where our Worcestershire elm trees are distributed we will be able to replace elm trees using seed or cuttings from Worcestershire stock. If you are interested please pick up a copy of the Elm Newsletter in March 1998 at the Worcestershire Biological Recorders meeting.
* A phylogenetic reconstruction of the Ulmus genus based upon morphological and sequence data is being developed by Jayne Armstrong of the Division of Environmental and Evolutionary Biology at the University of Glasgow. This will provide a new taxonomic framework which could enable the comprehensive identification of hybrid elms and other forms within the county.
|Armstrong, J, Gibbs, J, Webber, J, and Brasier, C. 1997. Elm Workshop Proceedings. Elm Newsletter No. 1. April 1997. The Conservation Foundation.
||Mabey, R. 1996. Flora Britannica. Sinclair-Stevenson, London pp 58-62.
||Milner, J.E. 1992. The Tree Book. (Channel Four Books) Collins & Brown, London pp 49-52.
||Mitchell, A. Reprint 1994. Trees of Britain & Northern Europe. HarperCollins Publishers, London pp 247-253.
||Peterken, G.F. Reprint 1994. Woodland Conservation and Management. Chapman & Hall, London.
||Rackham, 0. 1980. Ancient Woodland. Its History, Vegetation and Uses in England Edward Arnold, Norwich pp 255 -281.
||Rackham, 0. 1986. The History of the Countryside. J.M. Dent and Sons, London pp 232-247.
||Rackham, 0. 1994. The Illustrated History of the Countryside. Orion Publishing Group, London pp 88-92
||Richens, R.H. 1983. Elms. Cambridge University Press.
||Rodwell, J. S. (Ed) 1991. British Plant Communities, Volume 1: Woodland and Scrub. Cambridge University Press.
||Stace, C.A. 1991. New Flora of the British Isles. Cambridge University Press pp 137-141.
||Wilkinson, G. 1978. Epitaph for the Elm. Hutchinson & Co. Ltd, London.
|WBRC Home||Worcs Record Listing by Issue||Worcs Record Listing by Subject|