Ulmus davidiana var. japonica 'Prospector'

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Ulmus davidiana var. japonica 'Prospector'
Ulmus davidiana var Japonica 'Prospector'.JPG
'Prospector'
Variety Ulmus davidiana var. japonica
Cultivar 'Prospector'
OriginNational Arboretum, US

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. [1] A U.S. National Arboretum introduction (NA 55398), it was selected in 1975 from a batch of 1965 seedlings in Delaware, Ohio, and released without patent restrictions in 1990. [2] 'Prospector' proved moderately successful in the US National Elm Trial, averaging a survival rate of 76% overall. [3]

Contents

'Prospector' was introduced to the UK in 2009, by Hampshire & Isle of Wight Branch, Butterfly Conservation , as part of an assessment of DED-resistant cultivars as potential hosts of the endangered White-letter Hairstreak. [4]

Description

'Prospector' is a medium-size elm with a light-grey bark, attaining a height of approximately 14 m and developing a vase shape broadly similar to the American Elm but with lower-drooping branches . The deep-green, glossy obovate leaves are < 11 cm long by 8 cm wide, emerging orange-red and turning yellow in autumn. The perfect, apetalous wind-pollinated flowers emerge in early spring, before the leaves. The samara, 20 mm long by 8–10 mm wide, is narrowly obovate, the seed between centre and notch. Specimens grown in Hampshire, England, first flowered and fruited aged 10 years. The tree was also the first to flower every year, usually by mid-January. [5]

The tree grows at a comparatively modest pace in the United States; specimens planted at UC Davis as part of the National Elm Trial increased in height by 0.85 m and diameter at breast height by 2 cm in the first few years after establishment [6] The species does not sucker from roots. [7]

Pests and diseases

'Prospector' has featured in several elm trials in the United States, notably those conducted by the Northern Arizona University at Holbrook, eastern Arizona , and Townsend & Douglass [8] which established that the tree's survival rate after inoculation with the Dutch elm disease pathogen was 100%. In trials in California, the tree exhibited a singular sensitivity to boron concentrations of > 200 ppm in the soil, causing marginal necrosis on the leaves. [9] Moreover, although also highly resistant to elm leaf beetle Xanthogaleruca luteola (no damage whatsoever was recorded in the aforementioned trials at U C Davis [6] ) 'Prospector' is a favoured food of leaf hoppers which can seriously disfigure foliage by midsummer, and is moderately susceptible to the Japanese Beetle. [10] Tolerance of Elm Yellows in the United States was found to be poor. However, the disease has proved difficult to transmit experimentally to this cultivar, and there appear to be no natural infections. [11]

Cultivation

'Prospector' performed well in California, although it "needed substantial training in the first two to three years". [9] In Arizona, the tree proved unsuited to the hot, arid climate and suffered > 50% leaf scorch. In trials conducted by the University of Minnesota, 'Prospector' was appreciated for its extraordinary vigour but faulted for the weakness of its wood, notably stem breakage owing to bark inclusion. [12] Nonetheless, it is considered by the U.S. Department of Agriculture (USDA) as suitable for Zones 4–7. The tree is currently being evaluated in the National Elm Trial coordinated by Colorado State University.

'Prospector' was introduced to Europe by Butterfly Conservation in 2009 as part of its elm trials programme in Hampshire but has exhibited very slow growth, its stem increasing by just 2 mm in diameter at breast height per annum. [5]

The tree was also included in trials in New Zealand undertaken by Hortresearch at Palmerston North in the 1990s.

Synonymy

Ulmus wilsoniana C. K. Schneid. 'Prospector'.

Hybrid cultivars

Accessions

North America
Europe

Nurseries

North America

(Widely available)

Europe

Related Research Articles

<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 laciniata</i> Species of tree

Ulmus laciniata(Trautv.) Mayr, known variously as the Manchurian, cut-leaf, or lobed elm, is a deciduous tree native to the humid ravine forests of Japan, Korea, northern China, eastern Siberia and Sakhalin, growing alongside Cercidiphyllum japonicum, Aesculus turbinata, and Pterocarya rhoifolia, at elevations of 700–2200 m, though sometimes lower in more northern latitudes, notably in Hokkaido.

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

Ulmus microcarpa was named and first described by the Chinese botanist L. K. Fu, who discovered the tree in the Chayu broad-leaved forests of south-eastern Xizang at altitudes of around 2800 m during the 1973 Qinghai - Tibet Expedition. Unlike the majority of Tibet, the Chayu region has a subtropical highland climate featuring warm, wet, summers and mild, dry, winters. Commonly known as the Tibetan Elm, the tree was introduced to the United States in 2006, and the UK in 2013; it remains one of the rarest species of elm in cultivation.

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

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.

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</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> Sapporo Autumn Gold Elm cultivar

Ulmus 'Sapporo Autumn Gold' is one of the most commercially successful hybrid elm cultivars ever marketed, widely planted across North America and western Europe, although it has now been largely supplanted by more recent introductions. Arising from a chance crossing of the Japanese elm and Siberian elm, seed was sent in 1958 by Prof. Nobuku Takahashi and his colleagues at the Sapporo Botanical Garden of Hokkaido University, Sapporo, to Eugene Smalley at the University of Wisconsin–Madison. The patent issued in 1975 has expired, and there are now no propagation restrictions. However, the tree has proven weak-wooded on maturity, and its popularity has waned in Europe as a consequence of susceptibility to wind damage.

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

Ulmus gausseniiW. C. Cheng, the Anhui, or hairy, elm, is a medium size deciduous tree whose natural range is restricted to the valleys of the Langya limestone mountains of Chu Xian in Anhui Province, eastern China. The tree was most commonly found on the flood plains, indicating a tolerance of periodic inundation. However, U. gaussenii is now possibly the rarest and most endangered elm species, with only approximately 30 trees known to survive in the wild in 2009.

<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 americana</i> Valley Forge Elm cultivar

The American Elm cultivar Ulmus americana 'Valley Forge' was raised by the Agricultural Research Service in Maryland. The tree was released to wholesale nurseries without patent restrictions by the U. S. National Arboretum in 1995 after proving to have a high resistance to Dutch elm disease. 'Valley Forge' proved only moderately successful in the US National Elm Trial, averaging a survival rate of 66.7% overall, owing largely to environmental factors rather than susceptibility to disease.

The Japanese Elm cultivar Ulmus davidianavar.japonica 'Mitsui Centennial' is a cold-resistant selection raised at the Morden Experimental Station, Manitoba, Canada, in the 1970s, originally for use in the prairie regions. It was named to mark the centenary in 1980 of the London branch of Mitsui & Co., being one of a batch of Asiatic elms, some sourced from Canada, donated to the UK in that year by the company.

<i>Ulmus americana</i> Lewis & Clark Elm cultivar

The American elm cultivar Ulmus americana 'Lewis & Clark' is a development from the North Dakota State University (NDSU) Research Foundation breeding programme, released in 2004 to commemorate the 200th anniversary of the eponymous expedition. The cultivar was cloned from a tree discovered in 1994 along the Wild Rice River south west of Fargo, North Dakota, where all those around it had succumbed to Dutch elm disease; the tree remains in perfect health (2008). Prairie Expedition proved only moderately successful in the US National Elm Trial, averaging a survival rate of 62.6% overall, potentially due to environmental factors rather than susceptibility to Dutch elm disease. Nevertheless, Prairie Expedition is considered the hardiest of the American Elm cultivars, able to survive in Zone 3.

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.

<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.

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

Ulmus laciniata var. nikkoensisRehder, the Nikko elm, was discovered as a seedling near Lake Chūzenji, near Nikkō, Japan, and obtained by the Arnold Arboretum in 1905. The taxonomy of the tree remains a matter of contention, and has been considered possibly a hybrid of U. laciniata and U. davidiana var. japonica. However, in crossability experiments at the Arnold Arboretum in the 1970s, U. laciniata, a protogynous species, was found to be incompatible with U. davidiana var. japonica, which is protandrous.

<i>Ulmus</i> Morfeo Elm cultivar

Ulmus 'Morfeo' is a hybrid elm cultivar raised by the Istituto per la Protezione delle Piante (IPP), Florence, in 2000. 'Morfeo' arose from a crossing of the Dutch hybrid clone '405' and the Chenmou Elm, the latter a small tree from the provinces of Anhui and Jiangsu in eastern China, The '405' clone is a full sister of 'Groeneveld', a crossing of an English U. × hollandica and a French U. minor from the Barbier Nursery, Orléans.

<i>Ulmus minor</i> Dehesa de la Villa Elm cultivar

The Field Elm cultivar Ulmus minor 'Dehesa de la Villa' was cloned by root cuttings from a tree growing in the eponymous park within the Moncloa-Aravaca district of north-west Madrid, by researchers at the Escuela Técnica Superior de Ingenieros de Montes, Universidad Politėcnica de Madrid in 1990.

References

  1. ↑ Fu, L., Xin, Y. & Whittemore, A. (2002). Ulmaceae, in Wu, Z. & Raven, P. (eds) Flora of China, Vol. 5 (Ulmaceae through Basellaceae). Science Press, Beijing, and Missouri Botanical Garden Press, St. Louis, US.
  2. ↑ HortScience, 26, 81-82, 1991.
  3. ↑ Griffin, J.; et al. (2017). "Ten-Year Performance of the United States National Elm Trial" (PDF). Arboriculture & Urban Forestry. 43 (3). International Society of Arboriculture, Atlanta, US: 107–120. doi: 10.48044/jauf.2017.010 .
  4. ↑ Brookes, Andrew (2020). "Disease resistant elm cultivars" (PDF). Hampshire & Isle of Wight Branch Butterfly Conservation.
  5. 1 2 Brookes, A. H. (2022). Great Fontley Elm Trial, 2022 Report. Butterfly Conservation, Lulworth, England.
  6. 1 2 McPherson, G. et al. (2008). National elm trial: Initial report from Northern California. Western Arborist, Fall 2009, 32–36.
  7. ↑ Heybroek, Hans M. (1981). "The Japanese elm species and their value for the Dutch elm breeding program" (PDF). Proceedings of the Dutch Elm Disease Symposium and Workshop, October 5–9, Winnipeg, Manitoba: 78–90.
  8. ↑ Townsend A. M. & Douglass, L. W. Variation among American Elm Clones in Long-term Dieback, Survival, and Growth Response to Ophiostoma Inoculation
  9. 1 2 Costello, L. R. (2004). A 10-year evaluation of the performance of four elm cultivars in California, U.S. Journal of Arboriculture, March, 2004.
  10. ↑ 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, pp 15, 16. University of Kentucky.
  11. ↑ Sinclair, W. A., Townsend, A. M., Griffiths, H. M., & Whitlow, T. H. (2000). Responses of six Eurasian Ulmus cultivars to a North American elm yellows phytoplasma. Plant disease, Vol. 84, No.12, 1266–1270. American Phytopathological Society, St. Paul, MN
  12. ↑ Giblin, C. P. & Gillman, J. H. (2006). Elms for the Twin Cities: A Guide for Selection and Maintenance. University of Minnesota.
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