The hybrid elm cultivar Ulmus 'Hamburg' was originally raised by the Plumfield Nurseries, Fremont, Nebraska, circa 1932, after its discovery by Mr. Lloyd Moffet in a bed of Siberian Elm Ulmus pumila seedlings from Tekamah. It was later marketed by Interstate Nurseries, Hamburg, Iowa, in 1948, and claimed to be a hybrid of Ulmus pumila (female parent) and Ulmus americana. However it is now considered more likely that Ulmus rubra was the male parent.
Pests and diseases
'Hamburg' had not (by 1995) been widely tested for resistance to Dutch elm disease.
Largely confined to the United States, several were introduced to the UK. The tree is not known to have been introduced to Australasia.
- 'Hamburg Hybrid Elm': Interstate Nurseries, Hamburg, Iowa, Catalogue, Spring 1949.
- 'Hybrid Chinese Elm': Anon.
- North America
- Arnold Arboretum. Acc. nos. 520–53, 666–50.
- Exeter University Botanic Gardens, Exeter, Devon, UK. TROBI Champion, 17 m high, 55 cm d.b.h., listed as 'Hamburg Hybrid'.
- Green, Peter Shaw (1964). "Registration of cultivar names in Ulmus". Arnoldia. Arnold Arboretum, Harvard University. 24 (6–8): 41–80. Retrieved 16 February 2017.
- Santamour, Frank S.; Bentz, Susan E. (May 1995). "Updated Checklist of Elm (Ulmus) Cultivars for use in North America". Journal of Arboriculture. 21 (3): 122–131. Retrieved 20 June 2016.
- Ulmus 'Hamburg' in Handbuch der Ulmengewächse, www.ulmen-handbuch.de