Ulmus'Fiorente'

Ulmus'Fiorente'
'Fiorente' in autumn,Apennines,Italy.
Genus	Ulmus
Hybrid parentage	U. pumilaS.10 ×U. minorC. 02
Cultivar	'Fiorente'
Origin	IPP, Florence, Italy

Ulmus'Fiorente'is ahybridcultivarelm derived from a crossing of the Siberian ElmUlmus pumilaclone 'S.10' (female parent) fromLucca,Italy, with theUlmus minorclone 'C.02' from Lungarno,Florence,by theIstituto per la Protezione delle Piante(IPP), part of theItalian National Research Council,in Florence.The tree is protected byPlant Breeders' Rightsbestowed by theEUon 25 March 2010.

'Fiorente' was introduced to the UK in 2007 by Hampshire & Isle of Wight Branch,Butterfly Conservationas part of its assessment of DED-resistant cultivars as potential hosts of the endangeredWhite-letter Hairstreak.

Description

'Fiorente' is usuallymonopodial,and capable of exceptionally rapid development; during trials in the NorthernApennineon poor clay soils, growth exceeded 1.0 m in height and 1.5 cm in trunkd.b.hper annum. The tree's habit is conical, with a pronounced apical dominance; lateral growth is limited, the crown therefore rather columnar. The alternate leaves are of moderate size, < 8 cm long × < 5 cm broad; generallylanceolatein shape, they are rough on the upper surface and pubescent beneath,remaining green well into the autumn and shed relatively late, often persisting into December in the UK.The tree usually commences flowering in its fourth or fifth year, during late February in Italy,but as early as mid-January in southern England. Thesessilesamaraeare rounded, typically Ø15 mm, the seed central. The tree suckers from the roots, but only where the root has been exposed and damaged.

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  Bark of 20-year-old tree
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  Leaves
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  Samarae
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  'Fiorente' on marshland

Pests and diseases

Tested by inoculation with unnaturally high concentrations of the fungal pathogen, 'Fiorente' revealed a good resistance toDutch Elm Disease,sustaining 32% defoliation and 20% dieback; not as resistant asLutèce(20% defoliation and 12% dieback), but significantly better than the older Dutch cultivars such as'Lobel'(50% and 35.5% resp.) released in the early 1970s. Moreover, specimens in the field in Italy and England have exhibited no symptoms of DED orelm yellows;susceptibility to the elm leaf beetleXanthogaleruca luteolais much the same as that of the Field ElmUlmus minor.

Cultivation

In Italy, the cultivar's rapid growth has bestowed it economic potential as ahardwoodtimber andbiomasstree. However, its attractive, compact, form has seen it exclusively propagated and marketed as a root-balled street tree by the Eisele nursery inDarmstadt,Germany, as one of its 'Resista' series, and consequently it has never been available as a small bare-root whip as demanded by forestry.Introduced to southern England in 2007 byButterfly Conservation,the tree is not known to have been established in North America or Australasia.

Etymology

'Fiorente' translates as 'flourishing'.

Accessions

Europe

• Grange Farm Arboretum,Sutton St. James,Spalding,UK. Acc. no. 693.
• GreatFontleyFarm,Fareham,UK.Butterfly ConservationElm Trials plantation, two trees planted 2007.
• Royal Botanic Garden Edinburgh,UK. Acc. no. 20080340, 20180332
• Royal Botanic Gardens, Kew,UK. Acc. no. not known.
• Sir Harold Hillier Gardens,Ampfield,UK. Acc. no. 2008.0367

Nurseries

Europe

• Eisele nursery, Darmstadt, Germany
• Hillier's Nurseries,Liss,Hants. UK
• Noordplant,Glimmen,Netherlands.