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The Wych Elm cultivar Ulmus glabra 'Camperdownii', commonly known as the Camperdown Elm, was discovered about 1835–1840 as a young contorted elm growing in the forest at Camperdown House, in Dundee, Scotland, by the Earl of Camperdown's head forester, David Taylor. The young tree was lifted and replanted within the gardens of Camperdown House where it remains to this day. The original tree, which grows on its own roots, is less than 3 m tall, with a weeping habit and contorted branch structure. The earl's gardener is said to have produced the first of what are commonly recognised as Camperdown elms by grafting a cutting to the trunk of a wych elm.
Ulmus rubra, the slippery elm, is a species of elm native to eastern North America, ranging from southeast North Dakota, east to Maine and southern Quebec, south to northernmost Florida, and west to eastern Texas, where it thrives in moist uplands, although it will also grow in dry, intermediate soils. Other common names include red elm, gray elm, soft elm, moose elm, and Indian elm. The tree was first named as part of Ulmus americana in 1753, but identified as a separate species, Ulmus rubra, in 1793 by Pennsylvania botanist Gotthilf Muhlenberg. The slightly later name U. fulva, published by French botanist André Michaux in 1803, is still widely used in dietary-supplement and alternative-medicine information.
Ulmus thomasii, the rock elm or cork elm, is a deciduous tree native primarily to the Midwestern United States. The tree ranges from southern Ontario and Quebec, south to Tennessee, west to northeastern Kansas, and north to Minnesota.
Ulmus pumila, the Siberian elm, is a tree native to Central Asia, eastern Siberia, the Russian Far East, Mongolia, Tibet, northern China, India and Korea. It is also known as the Asiatic elm and dwarf elm, but sometimes miscalled the 'Chinese Elm'. It is the last tree species encountered in the semi-desert regions of central Asia. Described by Pallas in the 18th century from specimens from Transbaikal, Ulmus pumila has been widely cultivated throughout Asia, North America, Argentina, and southern Europe, becoming naturalized in many places, notably across much of the United States.
Ulmus 'Homestead' is an American hybrid elm cultivar raised by Alden Townsend of the United States National Arboretum at the Nursery Crops Laboratory in Delaware, Ohio. The cultivar arose from a 1970 crossing of the Siberian Elm Ulmus pumila with the hybrid N 215, the latter grown from seed sent in 1960 to the University of Wisconsin-Madison elm breeding team by Hans Heybroek of the De Dorschkamp Research Institute in the Netherlands. Tested in the US National Elm Trial coordinated by Colorado State University, 'Homestead' averaged a survival rate of 85% after 10 years. 'Homestead' was released to commerce without patent restrictions in 1984.
The hybrid elm cultivar Ulmus × hollandica 'Belgica', one of a number of hybrids arising from the crossing of Wych Elm with a variety of Field Elm, was reputedly raised in the nurseries of the Abbey of the Dunes, Veurne, in 1694. Popular throughout Belgium and the Netherlands in the 19th century both as an ornamental and as a shelter-belt tree, it was the 'Hollandse iep' in these countries, as distinct from the tree known as 'Dutch Elm' in Great Britain and Ireland since the 17th century: Ulmus × hollandica 'Major'. In Francophone Belgium it was known as orme gras de Malines.
The hybrid elm cultivar Ulmus × intermedia 'Coolshade' is an American hybrid cultivar cloned from a crossing of the Slippery, or Red, Elm Ulmus rubra and the Siberian Elm Ulmus pumila at the Sarcoxie Nurseries, Sarcoxie, Missouri, in 1946. At Arnold Arboretum, where there was a specimen, herbarium material was labelled Ulmus pumila 'Coolshade'.
Ulmus 'Morton Red Tip' is a hybrid cultivar raised by the Morton Arboretum from an open pollination of Accolade. The tree has occasionally been reported as a hybrid of Accolade with the Siberian Elm Ulmus pumila, an error probably owing to the commercial propagation of the tree by grafting onto U. pumila rootstocks. Tested in the US National Elm Trial coordinated by Colorado State University, Danada Charm averaged a survival rate of 77.5% after 10 years.
Ulmus 'Morton Stalwart', is a Morton Arboretum hybrid cultivar arising from a controlled crossing of Accolade with the hybrid of a Field Elm U. minor from eastern Russia and a Siberian Elm U. pumila. Tested in the US National Elm Trial coordinated by Colorado State University, Commendation averaged a survival rate of 85% after 10 years.
The Siberian elm cultivar Ulmus pumila 'Green King' was once believed to have been derived from a crossing of the Siberian Elm Ulmus pumila with the American Red Elm Ulmus rubra. However, it is now apparent the tree originated as a sport of U. pumila in 1939 at the Neosho Nurseries, Neosho, Missouri.
Ulmus 'Exoniensis', the Exeter elm, was discovered near Exeter, England, in 1826, and propagated by the Ford & Please nursery in that city. Traditionally believed to be a cultivar of the Wych Elm U. glabra, its fastigiate shape when young, upward-curving tracery, small samarae and leaves, late leaf-flush and late leaf-fall, taken with its south-west England provenance, suggest a link with the Cornish Elm, which shares these characteristics.
The Siberian elm cultivar Ulmus pumila 'Dropmore' was grown from seed collected by F. L. Skinner, of Dropmore, Manitoba, in Harbin, China.
The hybrid elm cultivar Ulmus 'Den Haag' is a Dutch development derived from a chance crossing of the Siberian Elm cultivar Ulmus pumila 'Pinnato-ramosa' and the Belgian Elm Ulmus × hollandica 'Belgica'. S. G. A. Doorenbos (1891-1980), Director of Public Parks in The Hague, finding that seeds he had sown in 1936 from the Zuiderpark 'Pinnato-ramosa' had hybridized with the local 'Belgica', selected six for trials. The best was cloned and grafted on 'Belgica' rootstock as 'Den Haag'; it was planted first in that city, then released to nurseries elsewhere in the Netherlands. The other five were also planted in The Hague.
The elm cultivar Ulmus 'Koopmannii' was cloned from a specimen raised from seed sent from Margilan, Turkestan by Koopmann to the Botanischer Garten Berlin c. 1880. Noted in 1881 as a 'new elm', it was later listed by the Späth nursery, catalogue no. 62, p. 6. 101, 1885, as Ulmus Koopmannii, and later by Krüssmann in 1962 as a cultivar of U. minor. Margilan is beyond the main range of Ulmus minor. Augustine Henry, who saw the specimens in Berlin and Kew, believed Koopmann's Elm to be a form of Ulmus pumila, a view not shared by Rehder of the Arbold Arboretum. Ascherson & Graebner said the tree produced 'very numerous root shoots', which suggests it may be a cultivar of U. minor. Until DNA analysis can confirm its origin, the cultivar is now treated as Ulmus 'Koopmannii'.
The hybrid elm cultivar Ulmus 'Hamburg' was originally raised by the Plumfield Nurseries, Fremont, Nebraska, circa 1932, after its discovery by Mr. Lloyd Moffet in a bed of Siberian Elm Ulmus pumila seedlings from Tekamah. It was later marketed by Interstate Nurseries, Hamburg, Iowa, in 1948, and claimed to be a hybrid of Ulmus pumila and Ulmus americana. However it is now considered more likely that Ulmus rubra was the male parent.
The hybrid cultivar Ulmus 'Androssowii'R. Kam., an elm of Uzbekistan sometimes referred to in old travel books as 'Turkestan Elm' or as 'karagach' [:black tree, = elm], its local name, is probably an artificial hybrid. According to Lozina-Lozinskaia the tree is unknown in the wild in Uzbekistan, and apparently arose from a crossing of U. densa var. bubyrianaLitv., which it resembles, and the Siberian Elm Ulmus pumila.
The 'dwarf' elm cultivar Ulmus 'Jacqueline Hillier' ('JH') is an elm of uncertain origin. It was cloned from a specimen found in a private garden in Selly Park, Birmingham, England, in 1966. The garden's owner told Hillier that it might have been introduced from outside the country by a relative. Hillier at first conjectured U. minor, as did Heybroek (2009). Identical-looking elm cultivars in Russia are labelled forms of Siberian Elm, Ulmus pumila, which is known to produce 'JH'-type long shoots. Melville considered 'JH' a hybrid cultivar from the 'Elegantissima' group of Ulmus × hollandica. Uncertainty about its parentage has led most nurserymen to list the tree simply as Ulmus 'Jacqueline Hillier'. 'JH' is not known to produce flowers and samarae, or root suckers.
The Siberian elm cultivar Ulmus pumila 'Dwarf Weeper' was discovered in a western Illinois garden and sold by the Arborvillage Nursery Holt, Missouri.
The Siberian elm cultivar Ulmus pumila 'Pinnato-ramosa' was raised by Georg Dieck, as Ulmus pinnato-ramosa, at the National Arboretum, Zöschen, Germany, from seed collected for him circa 1890 in the Ili valley, Turkestan by the lawyer and amateur naturalist Vladislav E. Niedzwiecki while in exile there. Litvinov (1908) treated it as a variety of Siberian elm, U. pumilavar.arborea but this taxon was ultimately rejected by Green, who sank the tree as a cultivar: "in modern terms, it does not warrant recognition at this rank but is a variant of U. pumila maintained and known only in cultivation, and therefore best treated as a cultivar". Herbarium specimens confirm that trees in cultivation in the 20th century as U. pumilaL. var. arboreaLitv. were no different from 'Pinnato-ramosa'.
The elm cultivar Ulmus 'Turkestanica' was first described by Regel as U. turkestanica in Dieck, Hauptcat. Baumschul. Zöschen (1883) and in Gartenflora (1884). Regel himself stressed that "U. turkestanica was only a preliminary name given by me; I regard this as a form of U. suberosa" [:U. minor ]. Litvinov considered U. turkestanicaRegel a variety of his U. densa, adding that its fruits were "like those of U. foliaceaGilibert" [:U. minor].
References
- ↑ Santamour, Frank S.; Bentz, Susan E. (May 1995). "Updated Checklist of Elm (Ulmus) Cultivars for use in North America". Journal of Arboriculture. 21 (3): 122–131. Retrieved 20 June 2016.
- ↑ Ulmus pumila 'Park Royal', millettegardenpictures.com
- ↑ Ulmus pumila 'Park Royal', guelph.arboretumexplorer