The

field elm ''Ulmus minor'' Mill., the field elm, is by far the most polymorphic of the European species, although its taxonomy remains a matter of contention. Its natural range is predominantly south European, extending to Asia Minor and Iran; its northern ...

cultivar A cultivar is a type of cultivated plant that people have selected for desired traits and when propagated retain those traits. Methods used to propagate cultivars include: division, root and stem cuttings, offsets, grafting, tissue culture, ...

''Ulmus minor'' 'Majadahonda' was cloned by grafting scions from a tree found growing in the suburb of Majadahonda, 16 km north-west of Madrid, by researchers at the Escuela Técnica Superior de Ingenieros de Montes,

Universidad Politėcnica de Madrid The Technical University of Madrid or sometimes called Polytechnic University of Madrid ( es, Universidad Politécnica de Madrid, UPM) is a public university, located in Madrid, Spain. It was founded in 1971 as the result of merging different Te ...

in 1993. The tree is one of a number found to have a very high resistance to Dutch Elm Disease, on a par with, if not greater than, the

hybrid Hybrid may refer to: Science * Hybrid (biology), an offspring resulting from cross-breeding ** Hybrid grape, grape varieties produced by cross-breeding two ''Vitis'' species ** Hybridity, the property of a hybrid plant which is a union of two dif ...

'Sapporo Autumn Gold'. In the Madrid study, the appearance of the tree was rated 4.1 / 5.
/ref> 'Majadahonda' was introduced to the UK in 2016, by Hampshire & Isle of Wight Branch, ''

Butterfly Conservation Butterfly Conservation (BC) is a UK-wide nonprofit environmentalist organization and charity dedicated to conserving butterflies, moths, and the environment. The charity uses its research to provide advice on how to conserve and restore butterfly ...

'', as part of an assessment of DED-resistant cultivars as potential hosts of the endangered White-letter Hairstreak. Brookes, A. H. (2021). ''Great Fontley Elm Trial, 2021 Report''. Butterfly Conservation, Lulworth, UK.

Description

'Majadahonda' grew at a modest rate of 61 cm per annum in the trials at Puerta de Hierro, Madrid. The branches, devoid of corky tissue, form a rounded crown. The leaves, on comparatively long 11 mm petioles, are elliptic, typically acuminate at the apex, the average length and width 50 × 29 mm, the margins distinctively simply serrate. Foliar density relative to 'Sapporo Autumn Gold' is described as 'high'. 'Majadahonda' had the latest leaf bud-burst phenology of the seven clones, in mid-April, with leaves not fully expanded until the end of April in Spain, (mid May in southern England ). Specimens grown in southern England attained sexual maturity aged six years, commencing flowering in week 8.

Cultivation

The cultivar underwent further trials in different environments in Spain, where it was again tested by inoculation in 2018. If resistance remains satisfactory, the tree may be released to commerce under licence. 'Majadahonda' is also being assessed as part of ''Butterfly Conservations elm trials in southern

Hampshire Hampshire (, ; abbreviated to Hants) is a ceremonial county, ceremonial and non-metropolitan county, non-metropolitan counties of England, county in western South East England on the coast of the English Channel. Home to two major English citi ...

, England, where it attained sexual maturity aged six years. The tree is unusual in that it cannot be propagated from cuttings as they do not callus, and is most commonly propagated by root cuttings.

Accessions

Europe

Grange Farm Arboretum The Grange Farm Arboretum is a small private arboretum comprising 3 hectares accommodating over 800 trees, mostly native and ornamental species or cultivars, notably oaks, ashes, walnuts and elms, growing on a calcareous loam.Ostler, J. (2009) ' ...

Lincolnshire Lincolnshire (abbreviated Lincs.) is a county in the East Midlands of England, with a long coastline on the North Sea to the east. It borders Norfolk to the south-east, Cambridgeshire to the south, Rutland to the south-west, Leicestershire ...

, UK. Acc. no. 1267. One small whip planted 2016. *Great Fontley Farm, nr.

Fareham Fareham ( ) is a market town at the north-west tip of Portsmouth Harbour, between the cities of Portsmouth and Southampton in south east Hampshire, England. It gives its name to the Borough of Fareham. It was historically an important manufact ...

, Hampshire, UK. ''Butterfly Conservation'' elm trial plantation. One small whip planted 2016.

References

{{Elm species, varieties, hybrids, hybrid cultivars and species cultivars , state=collapsed Field elm cultivar Ulmus articles with images Ulmus Technical University of Madrid elm clones