Ulmus 'Morton Stalwart'

Last updated
Ulmus 'Morton Stalwart'
Ulmus morton stalwart-commendation elm.JPG
Commendation, 14 years old. [1]
Genus Ulmus
Hybrid parentage Accolade × (U. minor × U. pumila)
Cultivar 'Morton Stalwart' = Commendation
OriginUS

Ulmus 'Morton Stalwart' (selling name Commendation), 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. [2] [3] Tested in the US National Elm Trial coordinated by Colorado State University, [4] Commendation averaged a survival rate of 85% after 10 years. [5]

Contents

Description

The branches are upright, but the form of the tree is more oval than vase-shaped; the leaves are relatively large. However, examples grown in the warmer climes of the southern United States have not impressed, and it was dismissed, along with its Morton stablemates Triumph and Vanguard, as 'ugly' by Michael Dirr, Professor of Horticulture at the University of Georgia , on account of its 'wild' growth and splaying branches.

Pests and diseases

Although resistant to Dutch elm disease in the United States, the tree is moderately susceptible to insects, [3] notably elm leaf beetle Xanthogaleruca luteola , [6] Japanese beetle [7] and Gypsy moth.

Cultivation

Commendation is vigorous and robust, adjudged the third fastest-growing cultivar of 17 assessed by the University of Minnesota and fourth out of 15 in trials at UC Davis. [6] The tree is also extremely tolerant of drought [8] and cold; in artificial freezing tests at the Morton Arboretum [9] the tree was found cold-hardy to −40°C.

Commendation was introduced by Chicagoland Grows [10] [3] and is currently being evaluated in the National Elm Trial [11] coordinated by Colorado State University. The tree was introduced to the UK in 2014, but is not known (2016) to have been introduced to Australasia.

Accessions

North America
Europe

Related Research Articles

<i>Ulmus pumila</i> Species of tree

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.

<i>Ulmus davidiana <span style="font-style:normal;">var.</span> japonica</i> Variety of tree

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.

<i>Ulmus</i> New Horizon Elm cultivar

Ulmus 'New Horizon' is an American hybrid cultivar raised by the Wisconsin Alumni Research Foundation (WARF), from a crossing of the Japanese Elm clone W43-8 = 'Reseda' with Siberian Elm clone W426 grown from seed collected from a street tree at Yankton, South Dakota. As selection 'W917' it is a sibling of 'Rebona'. Tested in the US National Elm Trial coordinated by Colorado State University, 'New Horizon' averaged a survival rate of 74% after 10 years. 'New Horizon' was patented in the US in 1994, while in Europe, it is marketed as one of the 'Resista' elms protected under EU breeders' rights.

<i>Ulmus macrocarpa</i> Species of tree

Ulmus macrocarpaHance, the large-fruited elm, is a deciduous tree or large shrub endemic to the Far East excluding Japan. It is notable for its tolerance of drought and extreme cold and is the predominant vegetation on the dunes of the Khorchin sandy lands in the Jilin province of north-eastern China, making a small tree at the base of the dunes, and a shrub at the top.

Ulmus pseudopropinquaWang & Li, occasionally known in the United States as the Harbin spring elm, is a small deciduous tree found only in Heilongjiang, the northeasternmost province in China. The tree has not been studied comprehensively, and it has been speculated it may be a natural hybrid of Ulmus davidiana var. japonica and Ulmus macrocarpa.

<i>Ulmus szechuanica</i> Species of tree

Ulmus szechuanicaFang, known as the Szechuan (Sichuan), or red-fruited, elm, is a small to medium deciduous Chinese tree found along the Yangtze river through the provinces of Sichuan, Jiangxi, Anhui, and Jiangsu.

<i>Ulmus</i> Frontier Elm cultivar

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.

<i>Ulmus</i> Homestead Elm cultivar

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.

<i>Ulmus</i> × <i>hollandica</i> Pioneer Elm cultivar

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.

<i>Ulmus</i> Urban Elm cultivar

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.

<i>Ulmus</i> Morton Elm cultivar

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.

<i>Ulmus</i> Morton Glossy Elm cultivar

Ulmus 'Morton Glossy' is a hybrid cultivar raised by the Morton Arboretum, Illinois. Originally named 'Charisma' until it was realized that name had already been registered for another plant, the tree was derived from a crossing of two other hybrid cultivars grown at the Morton: Accolade and Vanguard. Tested in the US National Elm Trial coordinated by Colorado State University, Triumph averaged a survival rate of 86% after 10 years. Triumph was introduced to the UK in 2006 by the Frank P. Matthews nursery in Worcestershire.

Ulmus 'Morton Plainsman' is a hybrid cultivar raised by the Morton Arboretum from a crossing of Siberian Elm and a Japanese Elm grown from openly pollinated seed donated by the Agriculture Canada Research Station at Morden, Manitoba. Tested in the US National Elm Trial coordinated by Colorado State University, Vanguard averaged a survival rate of 78% after 10 years.

<i>Ulmus</i> Morton Red Tip Elm cultivar

Ulmus 'Morton Red Tip' is a hybrid cultivar raised by the Morton Arboretum from an open pollination of Ulmus 'Morton'. 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.

<i>Ulmus americana</i> New Harmony Elm cultivar

The American elm cultivar Ulmus americana 'New Harmony' was raised by the Maryland Agricultural Research Service and released by the United States National Arboretum in 1995, along with 'Valley Forge'. 'New Harmony' proved the most successful U. americana cultivar in the US National Elm Trial, averaging a survival rate of 85.5% overall.

<i>Ulmus parvifolia</i> Emer II Elm cultivar

Ulmus parvifolia 'Emer II' or 'Emerald Vase' is a Chinese Elm cultivar that was cloned from a tree planted circa 1910 on the University of Georgia campus at Athens.

The Chinese Elm cultivar Ulmus parvifolia 'Emer I' or 'Emerald Isle' was cloned from a tree planted circa 1920 on the University of Georgia campus at Athens.

The Chinese Elm cultivar Ulmus parvifolia 'Hallelujah' is one of three American introductions made circa 1992 that were selected for their cold hardiness. 'Hallelujah' is known to have withstood -37 °C (-35 °F) in Missouri.

<i>Ulmus davidiana</i> var. <i>japonica</i> Prospector Elm cultivar

The Japanese elm cultivar Ulmus davidianavar.japonica 'Prospector' was originally treated as a cultivar of Wilson's elm U. wilsonianaSchneid., a species sunk as Ulmus davidiana var. japonica by Fu. A U.S. National Arboretum introduction, it was selected in 1975 from a batch of 1965 seedlings in Delaware, Ohio, and released without patent restrictions in 1990. 'Prospector' proved moderately successful in the US National Elm Trial, averaging a survival rate of 76% overall.

<i>Ulmus</i> Patriot Elm cultivar

Ulmus 'Patriot' is a hybrid cultivar raised by the United States National Arboretum in 1980. Derived from a crossing of the American hybrid 'Urban' with the Wilson's Elm cultivar 'Prospector', 'Patriot' was released to commerce, free of patent restrictions, in 1993. Tested in the US National Elm Trial coordinated by Colorado State University, 'Patriot' averaged a survival rate of 85% after 10 years.

References

  1. ↑ Cirrus Digital Commendation Elm
  2. ↑ Cirrus Digital Hybrid Elm - Ulmus (carpinifolia x pumila)
  3. 1 2 3 Morton Arboretum Commendation Elm
  4. ↑ "AgSci-Home page". Archived from the original on 2008-02-26.
  5. ↑ Griffin, J.; et al. (2017). "Ten-Year Performance of the United States National Elm Trial" (PDF). Arboriculture & Urban Forestry. 43(3):107–120. International Society of Arboriculture, Atlanta, US.
  6. 1 2 McPherson, G. et al. (2008). National elm trial: Initial report from Northern California. Western Arborist, Fall 2009, 32–36.
  7. ↑ Brady, C., Condra, J., & Potter, D. (2008) Resistance of Landscape-suitable Elm (Ulmus spp.) Cultivars to Japanese Beetle, Leaf Miners, and Gall Makers. 2008 Research Report, Nursery & Landscape Program, 15–16. University of Kentucky.
  8. ↑ Giblin, C. P. & Gillman, J. H. (2006). Elms for the Twin Cities: A Guide for Selection and Maintenance. University of Minnesota.
  9. ↑ Shirazi, A. M. & Ware, G. H. (2004). Evaluation of New Elms from China for Cold Hardiness in Northern Latitudes. International Symposium on Asian Plant Diversity & Systematics 2004, Sakura, Japan.
  10. ↑ "Chicagoland Grows® Plant Introduction Program".
  11. ↑ CSU Shade Tree Lab Archived 2008-02-26 at the Wayback Machine
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.