Ulmus 'Morton Plainsman' Vanguard
| Ulmus hybrid | |
|---|---|
| Hybrid parentage | U. pumila × U. davidiana var. japonica |
| Cultivar | 'Morton Plainsman' = Vanguard™ |
| Origin | USA |
Ulmus 'Morton Plainsman' (selling name Vanguard™) is a hybrid cultivar raised by the Morton Arboretum from a crossing of the Siberian Elm U. pumila (female parent) and a specimen of the Japanese Elm U. davidiana var. japonica grown from openly-pollinated seed donated by the Agriculture Canada Research Station at Morden, Manitoba.
Description
Vanguard has modest upright growth, increasing in height by an average of 0.8 m in an assessment at U C Davis,[1] with leaves much the same size and colour of the American Elm. However, its performance in the southern United States has not impressed, and it was dismissed, along with its Morton stablemates Commendation and Triumph, 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, Vanguard remains very susceptible to pests such as the elm-leaf beetle Xanthogaleruca luteola [1] , Japanese beetle,[2] and cankerworms.
Cultivation
In trials at the University of Minnesota, Vanguard was found to have the second highest (after Danada Charm) incidence of branch breakage occasioned by bark inclusions.[3] However, the tree has a high degree of drought and cold tolerance making it particularly suitable for afforestation in the Great Plains.[4][5] In artificial freezing tests at the Morton Arboretum [6] the LT50 (temp. at which 50% of tissues die) was found to be -40°C.
The tree is currently being evaluated in the National Elm Trial coordinated by Colorado State University. It is not known to have been introduced to Europe or Australasia.
Hybrid cultivars
Vanguard was crossed with the hybrid cultivar Accolade. A selection of the resultant seedlings was marketed under the name 'Charisma', later changed to 'Morton Glossy' = Triumph.
Accessions
- North America
- Bartlett Tree Experts. Acc. nos. 2001-106, 2001-108
- Brenton Arboretum, Dallas Center, Iowa. 5 trees, acquired 2009. Acc. no. not known.
- Chicago Botanic Garden, Glencoe, Illinois. 2 trees, no other details available.
- Dawes Arboretum , Newark, Ohio. 3 trees, no acc. details available.
- Holden Arboretum. Acc. no. 00–127
- Morton Arboretum. Acc. nos. 273–97, 4–2004, 156–2005.
- Smith College. Acc. no. 36505
- University of Idaho Arboretum. Two trees. Acc. no. 2000093
Nurseries
- North America
- Acorn Farms , Galena, Ohio.
- Bailey Nurseries , St. Paul, Minnesota.
- J. Frank Schmidt & Son , Boring, Oregon.
- Johnson's Nursery , Menomonee Falls, Wisconsin
- Sun Valley Garden Centre , Eden Prairie, Minnesota.
References
- 1 2 McPherson, G. et al. (2008). National elm trial: Initial report from Northern California. Western Arborist, Fall 2009, 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, 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.
- ↑ Santamour, F. S., & Bentz, S. E. Updated checklist of elm (Ulmus) cultivars for use in North America. Journal of Arboriculture, 21(3): May, 1995.
- ↑ Ware, G. (1992). Morton. Arb. Quarterly 28(1): 1–5, 1992.
- ↑ 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.
External links
- 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.
- http://www.mortonarb.org/plantinfo/plantclinic/phc/New-Elms-For-The-Landscape.pdf. Miller, F. (2002). New elms for the landscape and urban forest.