| Ulmus 'Morfeo' | |
|---|---|
 'Morfeo', Great Fontley, England | |
| Genus | Ulmus |
| Hybrid parentage | (U. × hollandica ×U. minor) ×U. chenmoui |
| Cultivar | 'Morfeo' |
| Origin | IPP, Florence, Italy |
Ulmus 'Morfeo' is ahybridelmcultivar raised by theIstituto per la Protezione delle Piante (IPP),Florence, in 2000.[1] 'Morfeo' arose from a crossing of the Dutch hybrid clone '405' (female parent) and theChenmou Elm, the latter a small tree from the provinces ofAnhui andJiangsu in eastern China,[2][3][4] The '405' clone is a full sister of'Groeneveld', a crossing of an EnglishU. ×hollandica and a FrenchU. minor from the Barbier Nursery,Orléans.[5]
'Morfeo' was patented and released to commerce in 2011.[4] It was solely propagated by the Georgio Tesi nursery in Italy, but production had ceased by 2020. The tree was introduced to the UK in 2006 (as 'FL509') by Hampshire and Isle of Wight Branch,Butterfly Conservation, as part of an assessment of DED-resistant cultivars as potential hosts of the endangeredWhite-letter Hairstreak.[6]
'Morfeo' is a robust, fast-growing tree able to freestand at a very early age.[7] The stem commences forking at between 1.5 and 2 m from the ground, the branches on juvenile trees with irregular patches of corky bark. The reddish branchlets bear mid – greenelliptic leaves, < 120 mm (avg. 88 mm) long × < 80 mm (avg. 56 mm) broad with 10 mm petioles. The leaves closely resemble those of theField Elm, with typically asymmetric base and acuminate apex; they turncrimson in late October, before falling in early November. Thesessilesamarae ripen in mid May, and are narrowly obovate, 17–22 mm long × 9 – 13 mm broad with the seed offset next to the notched apex.[4] In the UK the tree begins flowering in its fourth year, theperfect,apetalous wind-pollinated flowers appearing in mid March. The tree was noted to start suckering from roots in Italy when aged about 5 years, but this has not been observed in theButterfly Conservation trials in the UK.[6]
'Morfeo' has a very high resistance toDutch Elm Disease. In trials conducted by theIstituto per la Protezione delle Piante, Florence, 'Morfeo' sustained just 4.7% defoliation and 0.0% dieback when inoculated with unnaturally high concentrations of the fungal pathogen, compared with 19.8% / 11.7% resp. forLutece, and 50% / 35.5% resp. for'Lobel'.[4][3] However, 'Morfeo' is particularly susceptible to the phytoplasmaphloem necrosis, commonly known aselm yellows, a disease as yet (2025) unknown in the UK.[6]
'Morfeo' is no longer in commerce owing to its singular susceptibility to elm yellows. The tree was introduced to the UK in 2006 as a potential host plant for the White-letter Hairstreak butterflySatyrium w-album byButterfly Conservation, and has proven the fastest-growing of 13 cultivars on trial on a shallow sandy, gravelly loam overReading Beds, increasing instem diameter by 2.1 cm per annum. 'Morfeo' is also tolerant of waterlogged alluvium along rivers, and grows particularly well on exposed, elevated, chalk atopPortsdown Hill nearPortsmouth.[6] The cultivar was introduced to North America in 2010, at theNational Arboretum, Washington, D.C., and released from quarantine in 2013; it is not known to have been introduced toAustralasia.
The cultivar is named for Morfeo (English:Morpheus), theRoman god of dreams to whom the elm was sacred. There was an elm in Morpheus' domain, upon which hung the dreams fashioned by theOneiroi. From theAeneid byVirgil, translated byDryden:
Full in the midst of this infernal road,
An elm displays her dusky arms abroad:
The God of Sleep there hides his heavy head,
And empty dreams on ev'ry leaf are spread.