Ulmus 'Frontier' is an American hybrid cultivar, a United States National Arboretum introduction derived from a crossing of the European Field Elm Ulmus minor with the Chinese Elm Ulmus parvifolia in 1971. Released in 1990, the tree is a rare example of the hybridization of spring- and autumn-flowering elms. Tested in the US National Elm Trial coordinated by Colorado State University, 'Frontier' averaged a survival rate of 74% after 10 years.
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 in the US National Elm Trial. However, planting of the tree was not recommended, owing principally to its 'ugly' shape and susceptibility to Southwest injury. 'Homestead' was released to commerce without patent restrictions in 1984.
The hybrid elm cultivar Ulmus × hollandica 'Pioneer' is an American clone arising from the crossing of two European species, Wych Elm U. glabra and Field Elm U. minor. Raised by the USDA station at Delaware, Ohio, in 1971, 'Pioneer' was released to commerce in 1983.
Ulmus 'Urban' is an American hybrid elm cultivar selected from the progeny of a controlled crossing of the Siberian Elm Ulmus pumila with the Dutch clone '148' in 1958 by Toru Arisumi of the USDA at Columbus, Ohio. Clone '148' had been sent to the US from the Netherlands in 1952 by Johanna Went, leader of the elm research team at the Willie Commelin Scholten Phytopathology Laboratory in Baarn.
Ulmus 'Morton' is an elm cultivar cloned from a putative intraspecific hybrid planted at the Morton Arboretum in 1924, which itself originated as seed collected from a tree at the Arnold Arboretum in Massachusetts. Although this tree was originally identified as Ulmus crassifolia, it is now believed to have been a hybrid of the Japanese elm and Wilson's elm. Accolade has proven to be the most successful cultivar tested in the US National Elm Trial, averaging a survival rate of 92.5% overall. It had also become the most commonly planted elm in the US by 2023.
The American Elm cultivar Ulmus americana 'Princeton' was originally selected in 1922 by New Jersey nurseryman William Flemer of Princeton Nurseries for its aesthetic merit. 'Princeton' was later found to have a moderate resistance to Dutch elm disease (DED).
Ulmus parvifolia 'Emer II' or 'Emerald Vase' is a Chinese Elm cultivar selected by Dr. Michael A. Dirr and cloned in the late 1980s from a tree planted circa 1910 on the University of Georgia campus at Athens, that had survived ice-storms undamaged. It was patented in 1991.
The Chinese Elm cultivar Ulmus parvifolia 'Drake' was marketed by the Monrovia Nursery of Azusa, California, first appearing in their 1952–1953 catalogue.
Ulmus parvifolia 'Zettler' is a Chinese Elm cultivar cloned by Earl Cully from a tree growing near Jacksonville, Illinois, and patented in 1999. It is one of a small number of American lacebark elm introductions selected for their cold hardiness, others including 'King's Choice', 'Hallelujah', 'Glory' and 'Matthew'.
The Chinese Elm cultivar Ulmus parvifolia 'Frosty', or 'Frosty' lacebark elm, was intended primarily as a dwarf variegated variety. Krüssmann (1976) states that it was raised in Japan. It was first distributed by the Mitsch Nursery, Oregon, USA.
The Chinese Elm cultivar Ulmus parvifolia 'Glory' is one of the early American selections, best known for its winter hardiness. It does not appear in Santamour and Bentz's 'Updated Checklist of Elm (Ulmus) Cultivars for use in North America' (1995).
Ulmus davidianavar.japonica 'JFS-Bieberich' is a Japanese Elm cultivar that was raised by the Sunshine Nursery, Oklahoma, from seed collected in China by proprietor Steve Bieberich. Emerald Sunshine proved only moderately successful in the US National Elm Trial, averaging a survival rate of 70% overall.
The American Elm cultivar Ulmus americana 'Littleford' was cloned from a tree in Hinsdale, Illinois, circa 1915 by Littleford Nurseries of Downers Grove, Illinois, and first released in 1927. It was marketed in the 1930s by nearby Hinsdale Nurseries, successor to Littleford Nurseries, as 'Littlefordii'. In their 1925 catalogue Littleford Nurseries had written of their selection: "The growing of the American elm is a specialty with us; we consider it the leading shade and ornamental tree. Our trees are a selected strain of the V-shaped type, a stock of 15 to 20 thousand, all 2 ins. and up in size, transplanted twice and in splendid vigor for planting".
The American Elm cultivar Ulmus americana 'Moline' was cloned from a wild seedling transplanted to Moline, Illinois, from nearby Rock River Valley in 1903 and propagated from 1916 by the Klehm Nurseries, Arlington Heights, Illinois.
The American Elm cultivar Ulmus americana 'Morden' was cloned from a selection made by the Dominion Experimental Farm, Morden, Manitoba, in 1939 on account of its ability to withstand severe ice storms without breakage.
The American Elm cultivar Ulmus americana 'Jackson' was cloned c.1990 from an elm selected at Wichita, Kansas, which had reputedly shewn no signs of Dutch elm disease damage at over 50 years of age.
The Chinese Elm cultivar Ulmus parvifolia 'Garden City Clone' was raised in Kansas. The champion tree was 18 m tall in 1993; however, the name 'Garden City Clone' is not officially recognized.
Ulmus parvifolia 'BSNUPF' is a Chinese Elm cultivar, cloned from a chance seedling at Bold Spring Nursery, Bold Spring, Georgia. Patented in 2007, it was raised by John Barbour of Athena Trees, Monroe, Georgia.
The Chinese Elm cultivar Ulmus parvifolia 'Emerald Prairie' was raised by Kansas State University and released in 2004. The tree can reach a height of about 13 m, with a spread slightly less at approximately 12 m. It is distinguished by its superior foliar quality. The species and its cultivars are highly resistant, but not immune, to Dutch elm disease, and unaffected by the Elm Leaf Beetle Xanthogaleruca luteola. 'Emerald Prairie' is also noted for its resistance to black spot. 'Emerald Prairie' has yet to be grown beyond North America.
Ulmus parvifolia, commonly known as the Chinese elm or lacebark elm, is a species native to eastern Asia, including China, India, Japan, Korea, Vietnam, Siberia and Kazakhstan. It has been described as "one of the most splendid elms, having the poise of a graceful Nothofagus".
Carl Whitcomb's elms, Stillwater, Oklahoma [4]
