Ulmus × hollandica 'Pioneer'

Infobox Cultivar | name = "Ulmus × hollandica"


image_caption = 'Pioneer', Netherlands. Photo: Ronnie Nijboer, Bonte Hoek kwekerijen
hybrid = "U. glabra" × "U. minor"
cultivar = 'Pioneer'
origin = USAThe elm hybrid cultivar "Ulmus × hollandica" 'Pioneer' is an American development arising from the crossing of two European species, the Wych Elm "U. glabra" and the Smooth-leaved Elm "U. minor" subsp. "minor".

Description

'Pioneer' is very fast growing and distinguished by a dense, globular crown casting a heavy shade. The foliage is a very deep green, and the leaf shape similar to the Wych Elm.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.]

Pests and diseases

The tree's resistance to Dutch elm disease is somewhat less than other American hybrids, and for this reason the tree was omitted from the elm trials [http://www.for.nau.edu/cms/content/view/512/706/] in eastern Arizona conducted by the Northern Arizona University. 'Pioneer' is also severely damaged by the Elm Leaf Beetle "Xanthogaleruca luteola" [http://www.sunshinenursery.com/survey.htm] .

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.Giblin, C. P. & Gillman, J. H. (2006). "Elms for the Twin Cities: A Guide for Selection and Maintenance." University of Minnesota.] 'Pioneer' has had a very limited introduction to Europe,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.] featuring in street tree trials in several Dutch cities in the late 1990s. The tree is currently being evaluated in the National Elm Trial [http://treehealth.agsci.colostate.edu/research/nationalelmtrial/NET_Cultivars.htm] coordinated by Colorado State University.

Accessions

North America

*Bartlett Tree Experts acc. nos. 85-0195, 85-0199
*Denver Botanic Gardens, no details available
*Holden Arboretum acc. no. 90-58
*New York Botanical Garden acc. no. 955/97
*Smith College acc. no. 5603

Europe

None known.

Nurseries

North America

*Bailey Nurseries [http://www.baileynurseries.com/] , St. Paul, Minnesota
*ForestFarm [http://www.forestfarm.com/search/search.asp?aPage=1&index=genus&field-keywords=ulmus&Go.x=9&Go.y=3] , Williams, Oregon
*J. Frank Schmidt & Son Co. [http://www.jfschmidt.com/index.html] , Boring, Oregon
*Johnson's Nursery [http://www.johnsonsnursery.com/] , Menomonee Falls, Wisconsin
*Pea Ridge Forest [http://www.pearidgeforest.com/index.cfm?fuseaction=plants.main&alphaKey=U-Z&whichName=genus&showIntro=0] , Hermann, Missouri

Europe

*Westerveld Boomkwekerij B.V. [http://www.westerveldbv.nl/] , Opheusden, Netherlands

References

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".