Wych Elm is the species least affected by DED, so the most likely to be found in woodland edges and hedgerows. Sometimes called Scotch Elm, its Scots Gaelic name is 'Leam' and Irish 'Leamhan Sleibhe'. Usually only a minor component of mixed woodlands, it often grows with Common Ash, Sycamore and Rowan, especially on calcareous soils and screes.

Native to much of north-west Europe including Britain and Ireland, ranging on the continent from the mountains of northern Spain and southern France east to the Urals, its northern limit in southern Finland and southern limit by the Caspian in Iran. It is very widely distributed in Britain and Ireland, but more frequent in northern areas.

Monoecious, with usually hermaphrodite, self-incompatible flowers. Wind-pollinated (though insects are drawn by nectar) and, unlike most elms here, it sets viable seed and rarely suckers. Wind-dispersed. It commonly hybridises with other elms, especially Field Elm, to produce Dutch Elm (Ulmus × hollandica). Moderately long-lived (400 years).

A large forest tree (35-38m) with an open crown becoming broad and domed. Bark grey and smooth when young, darkening with long fissures and corky ridges, often with epicormic shoots and large basal burrs. Twigs dark and stiffly haired; buds purple-black, hairy. Leaves oval, very large (to 18cm, the largest of any native tree), rough above, downy below, doubly serrate, with a strongly asymmetric base and almost no petiole. Red-green flowers cluster before the leaves. Field Elm differs: smaller, smoother, longer-petioled leaves.

Cold-hardy and moderately drought-tolerant. Propagate by seed, not cuttings, to promote genetic diversity. Prefers some sun, thriving in hedgerows and woodland edges, but also more shade-tolerant than oak species. Can be coppiced. Foliage is favoured by browsing deer.

Food plant for larvae of the beautiful yet vulnerable White-letter Hairstreak butterfly (Satyrium w-album). Seeds enjoyed by finches.

Wych Elm is affected by DED but less than many elms, its decline less dramatic, partly because it grows where elm bark beetles (which carry the pathogen) are less at home, and because females find it a less desirable egg-laying target than Field Elm. Reproducing by seed, it is also more genetically diverse than clonal elms, and so inherently more resistant.

A valuable timber, used like Field Elm's but a little heavier and often with an attractive green hue. Primarily a forest tree, it also has several ornamental cultivars varying in foliage and form, including dwarf and weeping types.