The starting-points for List of elm cultivars, hybrids and hybrid cultivars were fourfold: (1) Green's 'Registration of Cultivar Names in Ulmus ' (1964),Arnoldia : Bulletin of the Arnold Arboretum, 24 July 1964, Vol 24 Nos 6-8, pp.40-80 based on the contemporary nomenclature of elm species and wild hybrids; (2) Krüssmann's confirmation or correction of cultivar-names in his monumental Handbuch der Laubgehölze (1976);Krüssmann, Johann Gerd, Handbuch der Laubgehölze (Vol. 3) (Paul Parey, Berlin and Hamburg, 1976); trans. Michael E. Epp, Manual of Cultivated Broad-Leaved Trees and Shrubs (Vol. 3) (Batsford, Timber Press, Beaverton, Oregon, 1984-6), pp.403-413 (3) Heybroek's table of Netherlands research clones in his essay 'Resistant elms for Europe' (1983; updated to include North American cultivars, 1996);D. A. Burdekin & K. D. Rushforth, revised by J. F. Webber: Agricultural Research Note 2: 'Elms resistant to DED' (Arboricultural Advisory & Information Service, 1996) and (4) Santamour and Bentz's 'Updated Checklist of Elm (Ulmus) Cultivars for use in North America' (1995).Santamour, Frank S.; Bentz, Susan E. (May 1995). 'Updated Checklist of Elm (Ulmus) Cultivars for use in North America', Journal of Arboriculture. 21 (3); pp.122–131. Since the 1990s there have been many new cultivars, some 'disease-resistant', either species cultivars (e.g. U. americana 'New Harmony') or cultivars with complex hybrid origins, the subject of ongoing trials. Information on these is taken from post-1990 scientific papers (see 'Further reading' below), pteleologists' articles,Tijdgat, M. (2020): Ulmus – Gebruikswaarde- en sortimentsonderzoek in de praktijk. Dendroflora Nr. 56-2020, p.73 Koninklijke Vereniging voor Boskoopse Culturen & Nederlandse Dendrologische Verenigingtreesandshrubsonline, UlmusUlmen-handbuch; ulmen-handbuch.deLars Lagerstedt, 'Almar i Sverige', Lustgarden, 2014, pp.53-78 and updated handbooks.Hillier, H. G., & sons. Hilliers' Manual of Trees & Shrubs (1970 - 2002). David & Charles, Newton Abbot, UK. There has not yet (2024) been a single recent collation comparable to Green's.
Green and Krüssmann acknowledged their debt to Rehder's list of elm-cultivar synonyms (1949),Rehder, Alfred, Bibliography of cultivated trees and shrubs hardy in the cooler temperate regions of the Northern Hemisphere (Jamaica Plain, Mass., 1949), pp.135-143 and to Schneider (1906),Schneider, Camillo Karl, Illustriertes handbuch der laubholzkunde (Jena 1906) pp.212-222 but the digitisation of older dendrologies, handbooks, and nursery-cataloguese.g. Späth, L., Catalogue 104 (1899–1900; Berlin), p.132-135, one of Späth, L., & sons, Baumschulen Nursery catalogues (1870s –1930s), Berlin.e.g. Hesse, Hermann Albert. Baumschulen: Preis- und Sortenliste. Nursery catalogues (1920s and 1930s). Weener, Germany.e.g. van Houtte, Louis, & son. Cultures de Louis van Houtte: Plantes Vivaces de Pleine Terre. Nursery catalogues of van Houtte & son, 1870s - 1890s. Ghent, Belgium. added cultivars and cultivation information missed or omitted by these four authorities.Among extant cultivars missing from Green and Krüssmann are U. glabra Huds. 'Superba' Blandford elm, the largest-leaved wych cultivar; U. glabra Huds. 'Concavaefolia', formerly U. montana var. cucullata, a 'boat'-leaved wych; U. × hollandica 'Canadian Giant', present in quantity in Victoria, Australia; U. × hollandica 'Viminalis' Späth, a narrow-leaved hybrid; Nottingham elm, discussed by Richens (1983); and U. pumila 'Pendula' Meyer, Dragon's Claw elm from northern China. The list below makes good some of these omissions, additions justified by the survival of extensive elm collections in disease-control locations such as Edinburgh (known to have been stocked from one such nursery), Brighton, Sweden, and New Zealand. Australia remains disease-free (2024) and has in quantity both well-known clones (e.g. 'Lutescens') and at least one old cultivar missed by Green and Krüssmann ('Canadian Giant'), as well as others that do not match European 'types'.Spencer, Roger, ed., Horticultural Flora of South-Eastern Australia, Vol. 2 (Sydney, 1995), Ulmus, p. 103-118 "Deliberate planting of selected clones," wrote Spencer (1995) "combined with chance hybridisation, has resulted in a mix of elms [in Australia] rather different from that in England"Spencer, Roger, ed., Horticultural Flora of South-Eastern Australia, Vol. 2 (Sydney, 1995), Ulmus, p.105 (see Elms in Australia).
The older elm cultivars (sometimes called 'varieties') usually bore simple descriptive Latin names (e.g. 'Tortuosa', 'Argenteo-Variegata', 'Stricta') under their contemporary species headings, or, later, under hybrid headings, as hybrids were then understood. Early lists, with no more information than this,e.g. Hand-list of trees and shrubs grown in the Arboretum, Kew Gardens (London, 1902), p. 613-625 abound, and are a further source for the articles listed below; one of the fullest is, e.g., Beissner's (1903).Beissner, Ludwig, Handbuch der Laubholz-Benennung (Berlin 1903), p.82-88 Amongst the more discursive treatments, however, that included cultivation-history and subjective comment (and sometimes illustrations), used in articles in this list, were those of Loudon (1838)Loudon, J. C., Arboretum et Fruticetum Britannicum (London 1838; 2nd edition 1854, pp.1373-1409 and Elwes and Henry (1913) in the UK,Elwes, H. J., and Henry, A., The trees of Great Britain & Ireland, Vol 7 (London 1913), p.1847-1929 Browne in USA (1851),Browne, Daniel Jay, The Trees of America (New York, 1851), pp.467-513 Petzold in Germany (1864),Petzold, Eduard Carl Adolf, and Kirchner, Arboretum Muscaviense (Muskau, 1864) p. 550-570 and Fontaine in the Netherlands (1965). These more discursive and subjective dendrologists are frequently cited in the articles listed below for information that would have been out of place in Green and Krüssmann.
The turn of the 20th century was the heyday of ornamental elm cultivation,A 1905 survey of tree types along main roads in Belgium found that of the 806,985 trees counted, 294,725 were elms, the most numerous genus. Elwes & Henry (1913), p.1870, note Bean, William Jackson, Trees and shrubs hardy in the British Isles (London 1916), pp.611-621 and Green noted that many cultivars had been inadequately described or illustrated before they were almost wiped out by the catastrophes of two Dutch elm disease epidemics and two world wars. Some had been described only from juvenile specimens whose ultimate size was unknown (e.g. U. minor 'Umbraculifera Gracilis' Späth). The digitisation of university and arboretum herbarium specimens, however, (leaves and fruit), bearing original labels, – a process more advanced, by the 2020s, in EuropeanNetherlands digital herbarium collection; bioportal.naturalis.nl and American collectionsAmerican digital herbarium collections; vplants.org than in those of the UK,Kew Herbarium's Digital Collection; apps.kew.orgRoyal Botanic Garden Edinburgh, Herbarium's Digital Collection; data.rbge.org.uk – and of old photographs of known cultivar-locations (see e.g. 'Atropurpurea'), has confirmed or supplemented the descriptions in many of the listed items. 'Lost' cultivars identified by Royal Botanic Garden Edinburgh since 2016 through such old planting-location information, and through herbarium specimens, – and returned to cultivation, – include U. × hollandica 'Wentworthii Pendula', U. minor 'Umbraculifera Gracilis' Späth, and U. glabra 'Concavaefolia'.Dr Max Coleman, 'Strange fruit offer lifeline to rare elms', Royal Botanic Garden Edinburgh; stories.rbge.org.ukDr Max Coleman, 'Survey of the elms of Holyrood Palace', Royal Botanic Garden Edinburgh, 22/07/2016 (updated 11/08/16)
Until the early 20th century, both wych cultivars and those of large-leaved European hybrids were often classified as Ulmus montana. The likely hybrid origin of some of the latter had, however, long been suspected, English carpenters for example referring to their 'Dutch elm' as 'bastard elm', while nurserymen knew that popular cultivars like 'Belgica' and 'Vegeta' could be raised reliably only by vegetative propagation or cloning, their seedlings not coming true to type. Not all hybrid elms planted in towns, therefore, were, strictly speaking, cultivars: some may have been one-off seedlings, unique genotypes, never repropagated vegetatively. (The same applies to species seedlings, for example non-cultivar wych planted in towns.)Information from Dr Max Coleman, RBGE. The nomenclature of hybrids was systematised by the mid-20th century. Research leading to the selection and breeding of cultivars resistant to Dutch elm disease was under way in the Netherlands from the 1920s, in the US from the 1930s, in Italy from the 1970s, and in Spain from the 1990s.Mittempergher, L., and Santini, A., 'The history of elm breeding'; researchgate.net
Species cultivars
Ulmus alata Lace Parasol UAMTF = Dwayne C. Moon, Ulmus alata 'UAMTF' description: Patent application, 28 August 2017; patents.justia.comElm Patents: 'UAMTF', PP30543, published 28 February 2019; patents.justia.com
Ulmus americana
Ulmus chenmoui JAB Morton =
Ulmus crassifolia Brazos Rim
Ulmus davidiana var. japonica
Ulmus glabra
Ulmus laevis
Ulmus minor
Ulmus parvifolia
Ulmus pumila
Hybrids and hybrid cultivars Ulmus × arbuscula U. glabra × U. pumila. Russia
Ulmus × arkansana U. serotina × U. crassifolia. US
Ulmus × brandisiana U. chumlia × U. wallichiana. India, Pakistan
Ulmus davidiana var. japonica × U. minor Ulmus davidiana var. japonica × U. minor. US
Ulmus × diversifolia U. glabra × U. minor 'Coritana' × U. minor 'Plotii'. UK
Ulmus × hollandica U. glabra × U. minor. [Dutch Elm, (US) Netherland Elm.] Europe
Ulmus × intermedia Ulmus pumila × Ulmus rubra. US
Ulmus × mesocarpa U. macrocarpa × U. davidiana var. japonica. Korea
Ulmus × androssowii U. minor × U. pumila. Central Asia, Spain, Italy Kew, Plants of the World Online, Ulmus × androssowii Litv.
Complex hybrids and other crossings Ulmus 'Amsterdam'. 'Bea Schwarz' × U. minor. Netherlands, before 1950. Ulmus 'Arno'. 'Plantyn' × U. pumila. Italy, 2006. Ulmus 'Cathedral'. U. davidiana var. japonica × U. pumila. US, 1994. Ulmus 'Charisma': See under 'Morton Glossy' = Ulmus 'Clusius'. ('Exoniensis' × U. wallichiana) × 'Bea Schwarz' selfed. Netherlands, 1983. Ulmus 'Columella'. 'Plantyn' × U. minor. Netherlands, 1992. Ulmus 'Curro'. U. minor R1 × U. minor S22. Spain, 2022. Dominguez, J., Macaya-Sanz, D., Gil, L, and Martin, J. A. (2022) Excelling the progenitors: Breeding for resistance to Dutch elm disease from moderately resistant and susceptible native stock. Forest Ecology and Management 511 (2022) 120113. Amsterdam: Elsevier. Ulmus 'Den Haag'. U. pumila × 'Belgica'. Netherlands, 1936. Ulmus 'Dodoens'. ('Exoniensis' × U. wallichiana) selfed. Netherlands, 1973. Ulmus 'Endeavor'. (U. americana × U. davidiana var. japonica) . US, 2022. West, T. P. (2022) Elms, the Good, the Bad and the Ugly. NDSU North Dakota Agricultural Experiment Station. Colleen Zacharias, 'The long game: a better future for new generation of disease-resistant elm trees' 'Endeavor' (photo 3); winnipegfreepress.com 9 Sept. 2022 Ulmus 'Europa'. ((U. glabra × U. minor) × 'Commelin'). Netherlands, 2021. Ulmus 'Fagel'. (U. wallichiana × ‘Commelin’) × (‘Dodoens’ × (U. glabra × U. minor)). Netherlands, 2021. Ulmus 'Frontier'. U. minor × U. parvifolia. US, 1990. Ulmus 'Klondike'. 'Plantyn' × 'Wredei'. Netherlands, 2021. Ulmus 'Homestead'. U. pumila × ('Commelin' × (U. pumila × 'Hoersholmiensis')). US, 1984. Ulmus 'Lobel'. ('Exoniensis' × U. wallichiana) × 'Bea Schwarz' selfed. Netherlands, 1973. Ulmus 'Marga'. U. minor R2 × U. minor S32. Spain, 2022. Ulmus 'Morfeo'. (U. × hollandica × U. minor) × U. chenmoui. Italy, 2010. Ulmus 'Morton' = . U. davidiana var. japonica × U. davidiana var. japonica. US, 2000. Ulmus 'Morton Glossy' = . 'Morton' = × 'Morton Plainsman' = . US, 2000.