Ulmus pumila 'Hansen' | |
---|---|
Species | Ulmus pumila |
Cultivar | 'Hansen' |
Origin | Not known |
The Siberian elm cultivar Ulmus pumila 'Hansen' is a little-known American tree of obscure origin, possibly raised from seed collected by the horticulturist and botanist Prof. Niels Hansen during his expedition to Siberia in 1897. [1]
Very similar to the species. [2] A specimen planted in 1978 at the Sir Harold Hillier Gardens in England had attained a height of 8 m by 2002.
The tree's current status in North America is not known; at least three mature specimens survive in the UK. Significantly, it is not listed in Green's digest of elm cultivar names published in 1964, suggesting a rather belated introduction to commerce. [3]
See under Ulmus pumila .
Ulmus rubra, the slippery elm, is a species of elm native to eastern North America. Other common names include red elm, gray elm, soft elm, moose elm, and Indian elm.
Ulmus pumila, the Siberian elm, is a tree native to Asia. It is also known as the Asiatic elm and dwarf elm, but sometimes miscalled the 'Chinese elm'. U. 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 wallichianaPlanch., the Himalayan elm, also known as the Kashmir elm and Bhutan elm, is a mountain tree ranging from central Nuristan in Afghanistan, through northern Pakistan and northern India to western Nepal at elevations of 800–3000 m. Although dissimilar in appearance, its common name is occasionally used in error for the cherry bark elm Ulmus villosa, which is also endemic to the Kashmir, but inhabits the valleys, not the mountain slopes. The species is closely related to the wych elm U. glabra.
Ulmus davidiana var. japonica, the Japanese elm, is one of the larger and more graceful Asiatic elms, endemic to much of continental northeast Asia and Japan, where it grows in swamp forest on young alluvial soils, although much of this habitat has now been lost to intensive rice cultivation.
Ulmus davidiana, also known as the David elm, or Father David elm, is a small deciduous tree widely distributed across China, Mongolia, Korea, Siberia, and Japan, where it is found in wetlands along streams at elevations of 2000–2300 m (6,500–7,500 ft). The tree was first described in 1873 from the hills north of Beijing, China.
The Dutch hybrid elm cultivar Ulmus × hollandica 'Groeneveld' was cloned in 1949 at the De Dorschkamp Institute, Wageningen, and released in 1963 in response to the earlier, less virulent form of Dutch elm disease that afflicted Europe shortly after the First World War. The cultivar was derived from a crossing of Dutch clones '49', and '1', a Field Elm Ulmus minor found in central France and marketed by the Barbier nursery in Orléans.
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.
Ulmus 'Plantyn' was one of three Dutch hybrid elms released by the Dorschkamp Research Institute for Forestry & Landscape Planning, Wageningen, in 1973. Derived from a crossing of the Dutch hybrids '202' and '302', it was to prove of great significance in later developments. A selfed seedling was to become the first Dutch clone to prove effectively immune to disease, released in 1989 as 'Columella'. 'Plantyn' was also destined to be the female parent of Lutèce released in 2002. In Italy, 'Plantyn' was used again as female parent in hybridizations with the Siberian Elm Ulmus pumila by the Istituto per la Protezione delle Piante (IPP), to create three new cultivars better adapted to the Mediterranean climate.
Ulmus 'Regal' is an American hybrid elm cultivar developed by the University of Wisconsin–Madison and released in 1983. 'Regal' was derived from seeds arising from the crossing of the Dutch hybrid clones 'Commelin' and '215' sent in 1960 by Hans M. Heybroek of the Dorschkamp Research Institute for Forestry & Landscape Planning, Wageningen, Netherlands.
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 Davey Elm, Ulmus × hollandica 'Daveyi', is an English hybrid cultivar of unknown specific origin, generally restricted to the valleys of Cornwall. Its apparent south-west England provenance, along with its foliage and habit, suggest that it may be a hybrid of Wych Elm and Cornish Elm.
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 seed, however, is on the stalk side of the samara, a feature of wych elm and its cultivars, whereas in hybrids it would be displaced towards the notch.
The Wych Elm cultivar Ulmus glabra 'Horizontalis', commonly known as the Weeping Wych Elm or Horizontal Elm, was discovered in a Perth nursery circa 1816. The tree was originally identified as 'Pendula' by Loddiges (London), in his catalogue of 1836, a name adopted by Loudon two years later in Arboretum et Fruticetum Britannicum, 3: 1398, 1838, but later sunk as a synonym for 'Horizontalis'.
The Wych Elm cultivar Ulmus glabra 'Cornuta', in cultivation before 1845 – Fontaine (1968) gives its provenance as France, 1835 – is a little-known tree, finally identified as a cultivar of U. glabra by Boom in Nederlandse Dendrologie 1: 157, 1959.
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.
Ulmus 'Louis van Houtte' is believed to have been first cultivated in Ghent, Belgium circa 1863. It was first mentioned by Franz Deegen in 1886. It was once thought a cultivar of English Elm Ulmus minor 'Atinia', though this derivation has long been questioned; W. J. Bean called it "an elm of uncertain status". Its dissimilarity from the type and its Belgian provenance make the 'Atinia' attribution unlikely. Fontaine (1968) considered it probably a form of U. × hollandica.
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 '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 Ulmus pumila cultivar 'Aurescens' was introduced by Georg Dieck at the National Arboretum, Zöschen, Germany, circa 1885. Dieck grew the tree from seed collected in the Ili valley, Turkestan by the lawyer and amateur naturalist Vladislav E. Niedzwiecki while in exile there. Dieck originally named the tree U. pinnato-ramosaf.aurescens.
The field elm cultivar Ulmus minor 'Viminalis' (:'willow-like'), occasionally referred to as the twiggy field elm, was raised by Masters in 1817, and listed in 1831 as U. campestris viminalis, without description. Loudon added a general description in 1838, and the Cambridge University Herbarium acquired a leaf specimen of the tree in 1866. Moss, writing in 1912, said that the Ulmus campestris viminalis from Cambridge University Herbarium was the only elm he thought agreed with the original Plot's elm as illustrated by Dr. Plot in 1677 from specimens growing in an avenue and coppice at Hanwell near Banbury. Elwes and Henry (1913) also considered Loudon's Ulmus campestris viminalis to be Dr Plot's elm. Its 19th-century name, U. campestris var. viminalis, led the cultivar to be classified for a time as a variety of English Elm. On the Continent, 'Viminalis' was the Ulmus antarcticaHort., 'zierliche Ulme' [:'dainty elm'] of Kirchner's Arboretum Muscaviense (1864).