| Ulmus 'Plinio' | |
|---|---|
 'Plinio' on chalk, Ports Down, UK. | |
| Genus | Ulmus |
| Hybrid parentage | 'Plantyn' ×U. pumila 'S.2' |
| Cultivar | 'Plinio' |
| Origin | IPP, Florence, Italy |
Ulmus 'Plinio' is ahybridelmcultivar derived from a crossing of theDutch cultivar'Plantyn' (female parent) with theSiberian ElmUlmus pumila clone 'S.2'. 'Plinio' was raised by theIstituto per la Protezione delle Piante (IPP), inFlorence and released for sale in 2003. 'Plinio' was introduced to the UK in 2004 by Hampshire & Isle of Wight Branch,Butterfly Conservation, as part of its assessment of DED-resistant cultivars as potential hosts of the endangeredWhite-letter Hairstreak.[1]
In Italy, 'Plinio' is a rounded tree with a broad crown, the width typically equalling 70% of height, and a short, often bent, trunk. The dark-green leaves are < 6.5 cm long by 3 cm broad and glabrous on both sides, on < 6 mmpetioles.[2][3] Like its compatriot'San Zanobi', the tree is not possessed of striking autumn colours, the leaves remaining green almost until they fall in late November. Theperfect,apetalous wind-pollinated flowers appear in mid March in the UK. Thesessilesamarae are round, 17–22 mm in diameter. Seed has exhibited a modest viability of between 10% and 20%.[1]
'Plinio' has a very high resistance toDutch Elm Disease. In trials conducted by theIstituto per la Protezione delle Piante, Florence, 'Plinio' sustained 7.8% defoliation and 3.9% dieback when inoculated with unnaturally high concentrations of the fungal pathogen, compared with 50% / 35.5% resp. for'Lobel', and 95% / 100% for 'CNR118', a Field Elm (Ulmus minor) native to Italy.[2]
Fast growing (though slower than its stablemate'San Zanobi') in Italy, where it commences flowering in its third year. The tree was introduced to theUK byButterfly Conservation in 2004 and is being evaluated at several sites inHampshire, where it has been found to be particularly successful on thin dryrendzinas. However, on more fertile soils, the relatively sparse and splaying top growth often exceeds stem and root development.[1]
As of 1 January 2018, the importation of 'Plinio' into the UK from Italy is prohibited, the plant unable to qualify for a phytopassport owing to the prevalence ofElm Yellows in the region of cultivation.[4]
'Plinio' is not known (2016) to have been introduced to North America or Australasia.
'Plinio' is named for the earlyRoman scientistPliny the Elder (Plinio inItalian).