Ulmus americana 'Morden'
|Ulmus americana 'Morden'|
|Origin||Dominion Experimental Farm, Morden, Manitoba, Canada|
The American Elm cultivar Ulmus americana 'Morden' was cloned from a selection made by the Dominion Experimental Farm, Morden, Manitoba, in 1939 on account of its ability to withstand severe ice storms without breakage.
Fast-growing and ultimately large, 'Morden' has been described as "rather coarse".
Pests and diseases
The tree is not known to have a resistance to Dutch elm disease (see Cultivation). No other specific information available, but the species generally is moderately preferred for feeding and reproduction by the adult Elm Leaf Beetle Xanthogaleruca luteola , and highly preferred for feeding by the Japanese Beetle Popillia japonica   in the United States. U. americana is the most susceptible of all the elms to verticillium wilt.
The tree was first marketed by the Patmore Nurseries, Brandon, Manitoba, circa 1948. A specimen planted in the Longenecker Horticultural Gardens at the University of Wisconsin–Madison Arboretum  in 1956 had died by 1974 "probably from Dutch elm disease"; no others are known to remain in cultivation.
- Green, Peter Shaw (1964). "Registration of cultivar names in Ulmus". Arnoldia. Arnold Arboretum, Harvard University. 24 (6–8): 41–80. Retrieved 16 February 2017.
- Miller, Fredric; Ware, George (2001-02-01). "Resistance of Temperate Chinese Elms (Ulmus spp.) to Feeding by the Adult Elm Leaf Beetle (Coleoptera: Chrysomelidae)". Journal of Economic Entomology. Oxford University Press (OUP). 94 (1): 162–166. doi:10.1603/0022-0493-94.1.162. ISSN 0022-0493.
- Miller, Fredric; Ware, George; Jackson, Jennifer (2001-04-01). "Preference of Temperate Chinese Elms ( Ulmus spp.) for the Adult Japanese Beetle (Coleoptera: Scarabaeidae)". Journal of Economic Entomology. Oxford University Press (OUP). 94 (2): 445–448. doi:10.1603/0022-0493-94.2.445. ISSN 0022-0493.
- "Elm Leaf Beetle Survey". Archived from the original on 2011-07-19. Retrieved 17 July 2017.
- Pegg, G. F. & Brady, B. L. (2002). Verticillium Wilts. CABI Publishing. ISBN 0-85199-529-2
- Arboretum News, Vol. 9, No. 1, January 1960. University of Wisconsin