The

hybrid Hybrid may refer to: Science * Hybrid (biology), an offspring resulting from cross-breeding ** Hybrid grape, grape varieties produced by cross-breeding two ''Vitis'' species ** Hybridity, the property of a hybrid plant which is a union of two dif ...

elm

cultivar A cultivar is a type of cultivated plant that people have selected for desired traits and when propagated retain those traits. Methods used to propagate cultivars include: division, root and stem cuttings, offsets, grafting, tissue culture, ...

''Ulmus'' 'Hamburg' was originally raised by the Plumfield Nurseries, Fremont,

Nebraska Nebraska () is a state in the Midwestern region of the United States. It is bordered by South Dakota to the north; Iowa to the east and Missouri to the southeast, both across the Missouri River; Kansas to the south; Colorado to the southwe ...

, circa 1932, after its discovery by Mr. Lloyd Moffet in a bed of

Siberian Elm ''Ulmus pumila'', the Siberian elm, is a tree native to Asia. It is also known as the Asiatic elm and dwarf elm, but sometimes miscalled the 'Chinese Elm' (''Ulmus parvifolia''). ''U. pumila'' has been widely cultivated throughout Asia, Nor ...

Ulmus pumila ''Ulmus pumila'', the Siberian elm, is a tree native to Asia. It is also known as the Asiatic elm and dwarf elm, but sometimes miscalled the 'Chinese Elm' (''Ulmus parvifolia''). ''U. pumila'' has been widely cultivated throughout Asia, Nor ...

'' seedlings from Tekamah. It was later marketed by Interstate Nurseries,

Hamburg (male), (female) en, Hamburger(s), Hamburgian(s) , timezone1 = Central (CET) , utc_offset1 = +1 , timezone1_DST = Central (CEST) , utc_offset1_DST = +2 , postal ...

Iowa Iowa () is a state in the Midwestern region of the United States, bordered by the Mississippi River to the east and the Missouri River and Big Sioux River to the west. It is bordered by six states: Wisconsin to the northeast, Illinois to the ...

, from 1948, as 'Interstate's New Hamburg Hybrid Elm'.

Green Green is the color between cyan and yellow on the visible spectrum. It is evoked by light which has a dominant wavelength of roughly 495570 Nanometre, nm. In subtractive color systems, used in painting and color printing, it is created by ...

stated that it was originally said be a hybrid of ''Ulmus pumila'' (female parent) and ''

Ulmus americana ''Ulmus americana'', generally known as the American elm or, less commonly, as the white elm or water elm, is a species of elm native to eastern North America, naturally occurring from Nova Scotia west to Alberta and Montana, and south to Flor ...

'', but the Hamburg Nurseries of Iowa made no such claim for it in their catalogues from 1948 onwards.Inter-State Nurseries, Hamburg, Iowa : spring 1950 catalogue; p.34
/ref> It is now considered more likely that ''

Ulmus rubra ''Ulmus rubra'', the slippery elm, is a species of elm native to eastern North America. Other common names include red elm, gray elm, soft elm, moose elm, and Indian elm. Description ''Ulmus rubra'' is a medium-sized deciduous tree with a spre ...

'' was the male parent, as it was also known as 'Hybrid Chinese Elm', and therefore probably synonymous with Plumfield Nurseries' 'Hybrid elm' of the same date, a known crossing of ''U. pumila'' and ''U. rubra'',Plumfield Nurseries, Fremont, Nebraska, 1943 catalogue, p.22
/ref> – and so, perhaps, also synonymous with ''Ulmus × intermedia'' 'Fremont', an elm of the same parentage found a little later in Plumfield Nurseries. An ''U. pumila'' × ''U. rubra'' parentage would, by present classification, make the cultivar ''Ulmus'' × ''intermedia'' 'Hamburg' . A similar erroneously conjectured crossing with ''U. americana'' occurred at Plumfield Nurseries in the 1930s, with their so-called "Wheatley hybrid elm" (apparently not the European 'Wheatley'), briefly marketed in 1934: "Our variety, an attractive round-headed rapid growing tree, with medium sized glossy leaves; originally imported from Holland and hybridized with American white elm, ''Ulmus americana'' ".

Description

'Hamburg' has been described as a hardy, very rapid grower, with much stronger branching than the

.Ulmus 'Hamburg' in ''Handbuch der Ulmengewächse'', www.ulmen-handbuch.d

/ref> Hamburg Nurseries described it as "a shapely tree with large, dark green leaves". Leaves 3 to 4.5 inches long, 1.5 to 2 inches wide.

Pests and diseases

'Hamburg' had not (by 1995) been widely tested for resistance to Dutch elm disease.

Cultivation

Largely confined to the United States, several were introduced to the UK. A tree in

Exeter University , mottoeng = "We Follow the Light" , established = 1838 - St Luke's College1855 - Exeter School of Art1863 - Exeter School of Science 1955 - University of Exeter (received royal charter) , type = Public , ...

Botanic Gardens,

Exeter Exeter () is a city in Devon, South West England. It is situated on the River Exe, approximately northeast of Plymouth and southwest of Bristol. In Roman Britain, Exeter was established as the base of Legio II Augusta under the personal comm ...

Devon Devon ( , historically known as Devonshire , ) is a ceremonial and non-metropolitan county in South West England. The most populous settlement in Devon is the city of Plymouth, followed by Devon's county town, the city of Exeter. Devon is ...

, however, at one time listed as 'Hamburg Hybrid' ( TROBI Champion, 17 m high, 55 cm

d.b.h. Diameter at breast height, or DBH, is a standard method of expressing the diameter of the trunk or bole of a standing tree. DBH is one of the most common dendrometric measurements. Tree trunks are measured at the height of an adult's breast, ...

), has since been found to be ''

Ulmus laevis ''Ulmus laevis'' Pall., variously known as the European white elm, fluttering elm, spreading elm, stately elm and, in the United States, the Russian elm, is a large deciduous tree native to Europe, from France northeast to southern Finland, east b ...

''. 'Hamburg' is not known to have been introduced to Australasia.

Notable trees

Two well-grown specimens, planted in 1953 and therefore among the earliest specimens sourced from the Hamburg Nurseries, stand (2022) in

Arnold Arboretum The Arnold Arboretum of Harvard University is a botanical research institution and free public park, located in the Jamaica Plain and Roslindale neighborhoods of Boston, Massachusetts. Established in 1872, it is the oldest public arboretum in N ...

, Massachusetts, USA.''U. rubra'' x ''U. pumila'' ('Hamburg'); ulmen-handbuch.de
/ref>

Synonymy

*'Hamburg Hybrid Elm': Interstate Nurseries,

Hamburg (male), (female) en, Hamburger(s), Hamburgian(s) , timezone1 = Central (CET) , utc_offset1 = +1 , timezone1_DST = Central (CEST) , utc_offset1_DST = +2 , postal ...

, Catalogue, Spring 1949. *'Hybrid Chinese Elm': Plumfield Nurseries, Fremont, Nebraska.

Accessions

;North America *

, US. Acc. nos. 520–53, 666–50.

References

{{Elm species, varieties, hybrids, hybrid cultivars and species cultivars , state=collapsed Elm cultivars Ulmus articles missing images Ulmus