Ulmus × hollandica 'Pioneer'
| Ulmus × hollandica | |
|---|---|
 'Pioneer', Netherlands. Photo: Ronnie Nijboer, Bonte Hoek kwekerijen |
|
| Details | |
| Hybrid parentage | U. glabra × U. minor |
| Cultivar | 'Pioneer' |
| Origin | USA |
The elm hybrid cultivar Ulmus × hollandica 'Pioneer' is an American clone arising from the crossing of two European species, Wych Elm U. glabra and Smooth-leaved Elm U. minor subsp. minor. Raised by the USDA station at Delaware, Ohio, in 1971, 'Pioneer' was released to commerce in 1983.
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[edit] Description
'Pioneer' is a fast-growing tree distinguished by a dense, globular crown, which as it matures becomes more broad than tall, like its U. glabra parent,[1] and casting a heavy shade. The leaves are deep green, and similar in shape to the Wych Elm,[2] colouring yellow and red in the fall.[3] The perfect, apetalous wind-pollinated flowers appear in early March.
[edit] Pests and diseases
The tree's resistance to Dutch elm disease, rated 4 out of 5 [4], is somewhat less than more recent American hybrids, and for this reason the tree was omitted from the elm trials [2] in eastern Arizona conducted by the Northern Arizona University. 'Pioneer' is also severely damaged by the Elm Leaf Beetle Xanthogaleruca luteola [3], sustaining more foliar damage (50%) than any other cultivar in an assessment conducted as part of the National Elm Trial at U C Davis. [5], and Japanese Beetle[6].
The tree's foliage was adjudged "resistant" to Black Spot by the Plant Diagnostic Clinic of the University of Missouri [4].
[edit] Cultivation
Considered "quite hardy in Saint Paul", and "definitely a good selection for the Twin Cities (St. Paul and Minnesota) urban forest" although very different in appearance to the American Elm.[7] 'Pioneer' has had a very limited introduction to Europe,[8] featuring in street tree trials in several Dutch cities in the late 1990s.
[edit] Accessions
[edit] North America
- Bartlett Tree Experts. Acc. nos. 85-0195, 85-0199
- Denver Botanic Gardens. No acc. details.
- Dominion Arboretum, Ottawa, Canada. No acc. details.
- Holden Arboretum. Acc. no. 90-58
- New York Botanical Garden. Acc. no. 955/97
- Smith College. Acc. no. 5603.
- University of Idaho Arboretum. One tree. Acc. no. 1990013
- U S National Arboretum [5], Washington, D.C., USA. Acc. no. 76233.
[edit] Europe
- Grange Farm Arboretum, Sutton St. James, Spalding, Lincolnshire, UK. Acc. No. 544
- NCCPG Collection, Brighton & Hove, UK: Tilbury Road, Hove (5 trees)
[edit] Nurseries
[edit] North America
- Bailey Nurseries [6], St. Paul, Minnesota
- ForestFarm [7], Williams, Oregon
- J. Frank Schmidt & Son Co. [8], Boring, Oregon
- Johnson's Nursery [9], Menomonee Falls, Wisconsin
- Pea Ridge Forest [10], Hermann, Missouri
- Sun Valley Garden Centre [11], Eden Prairie, Minnesota
[edit] Europe
- Westerveld Boomkwekerij B.V.[12], Opheusden, Netherlands
[edit] References
- ^ Arthur Lee Jacobson, 'Plant of the Month, 2008' (arthurleej.com/p-o-m-Oct08.html). Photographs of 'Pioneer' elm: www.ca.uky.edu and plants.bachmanslandscaping.com
- ^ Santamour, J., Frank, S. & Bentz, S. (1995). Updated checklist of elm (Ulmus) cultivars for use in North America. Journal of Arboriculture, 21:3 (May 1995), 121-131. International Society of Arboriculture, Champaign, Illinois, USA.
- ^ Photograph of autumn colouring of young 'Pioneer' elms, University of Washington campus: Arthur Lee Jacobson, 'Plant of the Month, 2008' [1]
- ^ Heybroek, H. M., Goudzwaard, L, Kaljee, H. (2009). Iep of olm, karakterboom van de Lage Landen (:Elm, a tree with character of the Low Countries). KNNV, Uitgeverij. ISBN 9709050112819
- ^ McPherson, G. et al. (2008). National elm trial: Initial report from Northern California. Western Arborist, Fall 2009, pp 32-36.
- ^ 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.
- ^ Giblin, C. P. & Gillman, J. H. (2006). Elms for the Twin Cities: A Guide for Selection and Maintenance. University of Minnesota.
- ^ Burdekin, D. A. & Rushforth, K. D. (Revised by Webber J. F. 1996). Elms resistant to Dutch elm disease. Arboricultural Research Note 2/96. Arboricultural Advisory and Information Service, Alice Holt, Farnham, UK.
[edit] External links
- http://www.extension.iastate.edu/Publications/SUL4.pdf Summary, inc. photographs, of elm cultivars resistant to Dutch elm disease available in the USA.
- http://fletcher.ces.state.nc.us/programs/nursery/metria/metria11/warren/elm.htm Warren, K., J. Frank Schmidt & Son Co. (2002). The Status of Elms in the Nursery Industry in 2000.
