The elm

cultivar A cultivar is a kind of Horticulture, cultivated plant that people have selected for desired phenotypic trait, traits and which retains those traits when Plant propagation, propagated. Methods used to propagate cultivars include division, root a ...

''Ulmus'' 'Toledo' was raised from seed collected in 1999 from a tree believed to be ''Ulmus minor'' growing in the eponymous city (), by researchers at the Escuela Técnica Superior de Ingenieros de Montes, Universidad Politėcnica de Madrid. However, retrospective

DNA analysis Genetic testing, also known as DNA testing, is used to identify changes in DNA sequence or chromosome structure. Genetic testing can also include measuring the results of genetic changes, such as RNA analysis as an output of gene expression, or ...

revealed that the clone also had ''

Ulmus pumila ''Ulmus pumila'', the Siberian elm, is a tree native to Asia. It is also known as the Asiatic elm and dwarf elm, but sometimes mistakenly called the "Chinese" elm (''Ulmus parvifolia''). ''U. pumila'' has been widely cultivated throughout A ...

DNA Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...

, the species introduced to Spain at the end of the 16th century, and has consequently been dropped from the research programme.Brookes, A. H. (2020). ''Great Fontley Elm Trial, 2020 Report''. Butterfly Conservation, Lulworth, UK. 'Toledo' was introduced to the UK in 2020 as part of an assessment by ''

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 butterf ...

'' of DED-resistant cultivars as potential hosts of the endangered

White-letter Hairstreak The white-letter hairstreak (''Satyrium w-album'') is a butterfly in the family Lycaenidae. Appearance and behaviour A dark little butterfly that spends the majority of its life in the tree tops, feeding on honeydew, making it best observed thr ...

Description

'Toledo' grew at a comparatively fast rate of 89 cm per annum in the trials at Puerta de Hierro, Madrid. The erect branches form an irregular crown and are devoid of corky tissue. The leaves, on 6 mm

petiole Petiole may refer to: *Petiole (botany), the stalk of a leaf, attaching the blade to the stem *Petiole (insect anatomy) In entomology, petiole is the technical term for the narrow waist of some hymenopteran insects, especially ants, bees, and ...

s, are

ovate Ovate may refer to: * Ovate (egg-shaped) leaves, tepals, or other botanical parts *Ovate, a type of prehistoric stone hand axe * Ovates, one of three ranks of membership in the Welsh Gorsedd * Vates or ovate, a term for ancient Celtic bards ...

, typically acuminate at the apex, the average length and width 47 × 27 mm, the margins doubly serrate. Foliar density relative to 'Sapporo Autumn Gold' is described as 'high'. In the Madrid study, the appearance of the tree was rated 2.9 / 5. The leaves flush in early April (week 14) in southern England.

Pests & diseases

'Toledo' was 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 diff ...

'Sapporo Autumn Gold'.

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 Ceremonial counties of England, ceremonial county in the East Midlands and Yorkshire and the Humber regions of England. It is bordered by the East Riding of Yorkshire across the Humber estuary to th ...

, UK. Acc. no. not known. *Great

Fontley Funtley – from the Anglo-Saxon, "Funtaleg", " spring field (clearing)", is a hamlet or exurb north of Fareham, Hampshire, England. It forms a projection towards the South Downs National Park and is generally included within Fareham's popul ...

Farm, Hampshire, UK. ''Butterfly Conservation'' elm trial plantation. One small sapling planted 2020.

References

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