Ulmus 'Morfeo'

Ulmus hybrid

Hybrid parentage (U. × hollandica × U. minor) × U. chenmoui
Cultivar 'Morfeo'
Origin IPP, Florence, Italy

Ulmus 'Morfeo' is a hybrid elm cultivar raised by the Istituto per la Protezione delle Piante (IPP), Florence, in 2000.[1] Originally identified as 'FL 509', 'Morfeo' arose from a crossing of the Dutch hybrid clone '405' (female parent) and the Chenmou Elm, the latter a small tree from the provinces of Anhui and Jiangsu in eastern China,[2][3][4] The '405' clone is a full sister of 'Groeneveld', a crossing of an English U. × hollandica and a French U. minor from the Barbier Nursery, Orléans.[5]

'Morfeo' was patented and released to commerce in 2011.[4]

Description

'Morfeo' is a robust, fast-growing tree able to freestand at a very early age.[6] 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 - green elliptic leaves, < 120 mm (avg. 88 mm) long × < 80 mm (avg. 56 mm) broad with 10 mm petioles. The leaves closely resemble those of the Field Elm, with typically asymmetric base and acuminate apex; they turn crimson in late October, before falling in early November. The sessile samarae 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, the perfect, apetalous wind-pollinated flowers appearing in mid March; the tree will usually begin to sucker from roots when aged about 5 years.

Pests and diseases

'Morfeo' has a very high resistance to Dutch Elm Disease. In trials conducted by the Istituto 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. for Lutece, and 50% / 35.5% resp. for 'Lobel'.[4] In UK some grafted plants of this cultivar were found infected by phytoplasma phloem necrosis, commonly known as elm yellows.[7]

Cultivation

'Morfeo' was introduced to the UK as a potential host plant for the White-letter Hairstreak butterfly Satyrium w-album by Butterfly Conservation. [7] The tree has proven very fast growing, the fastest of 13 cultivars on trial on a shallow sandy, gravelly loam over Reading Beds, increasing in stem diameter by 2.1 cm per annum. 'Morfeo' is also tolerant of heavy winter-wet soils. [8]

The cultivar has been introduced to North America, with the arrival of two small specimens at the National Arboretum, Washington, D.C. in November 2010, and released from quarantine in 2013; it is not known to have been introduced to Australasia. 'Morfeo' is (2015) only in commerce in Italy.

Etymology

The cultivar is named for Morfeo (English: Morpheus), the Roman god of dreams to whom the elm was sacred. Morpheus was the eldest of the Oneiroi, sons of Nyx, goddess of the night. There was an elm in Morpheus' domain, upon which hung the dreams fashioned by the Oneiroi. From the Aeneid by Virgil, translated by Dryden:

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.

Accessions

Europe

North America

Nurseries

Europe

References

  1. ↑ Mittempergher, L, & Porta, N. la, (1991). Hybridization studies in the Eurasian species of elm (Ulmus spp.). Silvae Genetica 40, 237-243.
  2. ↑ Fu, L. & Jin J. (eds). (1992). China Red Data Book. Rare and endangered plants. Vol. 1. Science Press, Beijing.
  3. ↑ Fu, L., Xin, Y. & Whittemore, A. (2002). Ulmaceae, in Wu, Z. & Raven, P. (eds) Flora of China, Vol. 5 (Ulmaceae through Basellaceae). Science Press, Beijing, and Missouri Botanical Garden Press, St. Louis, USA.
  4. 1 2 3 4 Santini, A., Pecori, F., Pepori, A., & Brookes, A. (2011). 'Morfeo' Elm: a new variety resistant to Dutch elm disease. Forest Pathology, April 2012, Vol. 42, Issue 2, 171–176
  5. ↑ Heybroek, H. M. (1993). The Dutch Elm Breeding Program. In Sticklen & Sherald (Eds.) (1993). Dutch Elm Disease Research, Chapter 3. Springer Verlag, New York, USA
  6. ↑ Santini, A., Pecori, F., Pepori, A. L., Ferrini, F., Ghelardini, L. Genotype × environment interaction and growth stability of several elm clones resistant to Dutch elm disease. Forest Ecology and Management. Elsevier B. V., Netherlands.
  7. 1 2 Brookes, A. H. (2015). Disease-resistant elms, Butterfly Conservation trials report, 2015 Butterfly Conservation, Hants & IoW Branch, England.
  8. ↑ Brookes, A. H. (2015). Great Fontley Elm Trial, 2015 Report. Butterfly Conservation, Lulworth, England.
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