''Ulmus'' 'Arno' is an Italian

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 ...

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, ...

derived from a crossing of 'Plantyn' (female parent) with the

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 ...

'' clone S.2. It was raised by the

Istituto per la Protezione delle Piante The Istituto per la Protezione delle Piante (IPP), or 'Institute of Plant Protection', is part of the Food Department of the Consiglio Nazionale delle Ricerche (CNR; "Italian National Research Council"), an Italian government organization with the ...

(IPP) in

Florence Florence ( ; it, Firenze ) is a city in Central Italy and the capital city of the Tuscany region. It is the most populated city in Tuscany, with 383,083 inhabitants in 2016, and over 1,520,000 in its metropolitan area.Bilancio demografico an ...

, and released in 2007. However, 'Arno' was not a commercial success; propagation had ceased by 2010, and it is no longer patent protected. 'Arno' was introduced to the UK in 2007 by Hampshire & Isle of Wight Branch, ''

Butterfly Conservation Butterfly Conservation (BC) is a UK-wide nonprofit environmentalist organization and charity dedicated to conserving butterflies, moths, and the environment. The charity uses its research to provide advice on how to conserve and restore butterfly ...

'', as part of an assessment of DED-resistant cultivars as potential hosts of the endangered

White-letter Hairstreak The white-letter hairstreak (''Satyrium w-album'') is a butterfly in the family Lycaenidae. Appearance and behaviour A dark little butterfly that spends the majority of its life in the tree tops, feeding on honeydew (secretion), honeydew, making ...

.Brookes, A. H. (2020). ''Great Fontley Elm Trial - 2020 Report.'' Butterfly Conservation, Lulworth, UK. ''.

Description

'Arno' is of erect habit with upward main branches forming an oval to round crown, but can sucker freely from its roots. In Italy the tree is remarkably fast-growing, though not as quick as its contemporary 'Fiorente'. The trunk is straight, and usually forks at a height of 3 m; the bark is grey-green, with grey-orange fissures. The alternate deciduous leaves are of moderate size, < 9 cm long by < 5 cm wide,

ovate Ovate may refer to: *Ovate (egg-shaped) leaves, tepals, or other botanical parts *Ovate, a type of prehistoric stone hand axe *Ovates, one of three ranks of membership in the Welsh Gorsedd *Vates In modern English, the nouns vates () and ovat ...

lanceolate The following is a list of terms which are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (a single leaf blade or lamina) or compound (with several leaflets). The edge of the leaf may be regular o ...

, featuring yellowish - green undulate margins; they remain green throughout autumn and are usually shed relatively late. The perfect,

apetalous Petals are modified leaves that surround the reproductive parts of flowers. They are often brightly colored or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''corolla''. Petals are usually ...

wind-pollinated flowers appear in late February; the tree begins flowering at the age of five years in Italy. The

sessile Sessility, or sessile, may refer to: * Sessility (motility), organisms which are not able to move about * Sessility (botany), flowers or leaves that grow directly from the stem or peduncle of a plant * Sessility (medicine), tumors and polyps that ...

samara Samara ( rus, Сама́ра, p=sɐˈmarə), known from 1935 to 1991 as Kuybyshev (; ), is the largest city and administrative centre of Samara Oblast. The city is located at the confluence of the Volga and the Samara (Volga), Samara rivers, with ...

e are ovate, 14 × 17 mm. File:Photo of Ulmus hybrid cultivar 'Arno' bark, tree aged 20 years.jpg, 'Arno' bark, tree aged 20 years Image: Arno leaf.JPG, Leaf and 1 Euro coin. Image: Arno leaf fungal disease 1.jpg, ''Rhytisma ulmi'' on 'Arno'

Pests and diseases

Tested by inoculation with the pathogen, 'Arno' displayed moderate resistance ('3') to

Dutch Elm Disease Dutch elm disease (DED) is caused by a member of the sac fungi (Ascomycota) affecting elm trees, and is spread by elm bark beetles. Although believed to be originally native to Asia, the disease was accidentally introduced into Americas, America ...

, lower than 'Lobel' and Plantyn' ('4'). 'Arno' is also resistant to

Elm Yellows Elm yellows is a plant disease of elm trees that is spread by leafhoppers or by root grafts."Elm Yellows." Elmcare.Com. 19 Mar. 2008 . Elm yellows, also known as elm phloem necrosis, is very aggressive, with no known cure. Elm yellows occurs in the ...

; susceptibility to the elm leaf beetle ''

Xanthogaleruca luteola ''Xanthogaleruca luteola'', commonly known as the elm-leaf beetle, is a beetle species in the family Chrysomelidae that is native to Europe but invasive in other parts of the world.http://cisr.ucr.edu/elm_leaf_beetle.html - Center for Invasive Sp ...

'' is much the same as that of the Field Elm ''

Ulmus minor ''Ulmus minor'' Mill., the field elm, is by far the most polymorphic of the European species, although its taxonomy remains a matter of contention. Its natural range is predominantly south European, extending to Asia Minor and Iran; its northern ...

''.Santini A., Fagnani A., Ferrini F., Ghelardini L., & Mittempergher L., (2007). Fiorente and Arno elm trees. ''HortScience'' June 2007, Volume 42, Issue 3, 712–14. American Society for Horticultural Science, Alexandria, VA 22314, US. In trials in England, leaves were afflicted by the fungus ''

Rhytisma ulmi ''Rhytisma ulmi'' is a species of fungus commonly found on elm Elms are deciduous and semi-deciduous trees comprising the flowering plant genus ''Ulmus'' in the plant family Ulmaceae. They are distributed over most of the Northern Hemisphe ...

''.

Cultivation

'Arno' has reputedly performed extremely well in trials in northern Italy, even where grown on poor clay soils. The clone was introduced to the UK by ''

'' in 2007, and to The Netherlands by Noordplant, but is not known elsewhere in Europe, and has not been introduced to North America or Australasia. 'Arno' is no longer in commerce in Italy.

Etymology

'Arno' is named for the river

Arno The Arno is a river in the Tuscany region of Italy. It is the most important river of central Italy after the Tiber. Source and route The river originates on Monte Falterona in the Casentino area of the Apennines, and initially takes a s ...

which flows through the city of Florence.

Accessions

Europe

Grange Farm Arboretum The Grange Farm Arboretum is a small private arboretum comprising 3 hectares accommodating over 800 trees, mostly native and ornamental species or cultivars, notably oaks, ashes, walnuts and elms, growing on a calcareous loam.Ostler, J. (2009) ' ...

Sutton St James Sutton St James is a village and civil parish in the South Holland district of Lincolnshire, England, about south-west of Long Sutton. Lying in the Lincolnshire Fens, Sutton St James did not exist at the time of the 1086 ''Domesday Book''. Su ...

, Spalding, Lincs., UK. Acc. no. 816. *

Royal Botanic Garden Edinburgh The Royal Botanic Garden Edinburgh (RBGE) is a scientific centre for the study of plants, their diversity and conservation, as well as a popular tourist attraction. Founded in 1670 as a physic garden to grow medicinal plants, today it occupies ...

. Acc. no. 20070205 *

Netherlands Plant Collection Ulmus ) , anthem = ( en, "William of Nassau") , image_map = , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of the Netherlands , established_title = Before independence , established_date = Spanish Netherl ...

Wijdemeren Wijdemeren () is a municipality in the Netherlands, in the province of North Holland, on the western border of the Gooi region. Wijdemeren contains many lakes. In the north(east) ''Spiegelplas'' and ''Ankeveense Plassen'', in the (south)west ''Loo ...

Netherlands ) , anthem = ( en, "William of Nassau") , image_map = , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of the Netherlands , established_title = Before independence , established_date = Spanish Netherl ...

, planted 2020Netherlands Plant Collection: Iepen, ''Ulmus''
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Nurseries

None.

References

{{Elm species, varieties, hybrids, hybrid cultivars and species cultivars , state=collapsed Hybrid elm cultivar Ulmus articles with images