Ulmus × hollandica 'Superba'

Ulmus × hollandica cultivar

'Superba', Magdeburg, 1907 (described here by its synonym, Ulmus praestans E. Schoch)
Hybrid parentage U. glabra × U. minor
Cultivar 'Superba'
Origin Belgium

The hybrid elm cultivar Ulmus × hollandica 'Superba', once commonly known in the UK as the Canterbury Elm, is one of a number of hybrids arising from the crossing of the Wych Elm U. glabra with a variety of Field Elm U. minor. It was identified by Morren as U. montana (: glabra) var. superba in Journal D'Agriculture Pratique de Belgique: 411 1848 and much later by Krüssmann in Handbuch der Laubgehölze 2: 537, 1962 as a cultivar.[1] Krüssman (1984) states that 'Superba' is synonymous with the former U. praestans E. Schoch.[2]

Description

'Superba', according to the full description in Elwes and Henry (1913), is a rapidly growing, narrow, pyramidal tree with smooth bark and steeply ascending branches. It bears large smooth biserrate leaves, 8–12 cm (3–4 in) long and 4–6 cm broad, very oblique at the base and similar to those of the Wych Elm, but with petioles 5–10 mm long. The flowers too resemble those of the Wych Elm.[3] Krüssman (1984), who gives a leaf illustration, adds that the elliptic samarae are 1.5–2 cm long with the seed nearly central, that the leaves have 15–18 pairs of veins, and that the leaves are retained late into autumn.[4]

Herbarium leaf-specimens suggest that more than one clone has been called U. × hollandica 'Superba' (see External links below).

Pests and diseases

The tree is very susceptible to Dutch elm disease.

Cultivation

'Superba' was reputed by Louis Späth to have been much valued as a street tree, notably in Magdeburg, Germany.[5] A 1907 photograph shows an avenue of the tree in Magdeburg, described as U. praestans E. Schoch, a "hybrid between U. scabra [U. glabra] and U. campestris [U. minor]" - i.e. as a form of U. × hollandica.[6] 'Superba' was cultivated in the UK by Masters at Canterbury in the early 19th century, where it became known as 'Master's Canterbury Seedling' or simply the 'Canterbury Elm', and later, confusingly, as U. montana (: glabra) 'Major'.[5] 'Superba' was reintroduced to the UK at Kew Gardens in 1900, obtained from the Späth nursery in Berlin, and remains represented by a specimen at Wakehurst Place donated in 1949; it survives by being treated as a hedging plant, too low to attract the attentions of the Scolytus beetles which act as vectors of Dutch elm disease. Three specimens supplied by Späth to the Royal Botanic Garden Edinburgh in 1902 as U. montana superba may survive in Edinburgh as it was the practice of the Garden to distribute trees about the city (viz. the Wentworth Elm);[7] the current list of Living Accessions held in the Garden per se does not list the plant.[8] An old narrowly pyramidal U. × hollandica with steeply ascending branches, which stands in Regent Road Park, Edinburgh (2016), has leaves that match the RBGE 1902 herbarium-specimen of U. montana superba (see External links below).

It is not known whether 'Superba' was introduced to North America. An elm identified as 'Superba' was photographed at the Ellwanger and Barry nursery at Mount Hope, Rochester, New York, c. 1900. However, the photograph is also endorsed 'Belgian Elm', which it more strongly resembles.[9]

Synonymy

Accessions

Europe

References

  1. 1 2 3 Green, Peter Shaw (1964). "Registration of cultivar names in Ulmus" (PDF). Arnoldia. Arnold Arboretum, Harvard University. 24 (6–8): 41–80. Retrieved 20 June 2016.
  2. 1 2 Krüssman, G. (1984) Manual of Cultivated Broad-Leaved Trees & Shrubs (1984) vol. 3
  3. ↑ Elwes and Henry (1913), p.1873
  4. ↑ Krüssman, Gerd, Manual of Cultivated Broad-Leaved Trees & Shrubs (1984 vol. 3), p.410
  5. 1 2 Elwes, Henry John; Henry, Augustine (1913). The Trees of Great Britain & Ireland. 7. pp. 1873–1874. Republished 2004 Cambridge University Press, ISBN 9781108069380
  6. ↑ Heinricy, B (1908). "Baumpflanzungen in den städten". Die Gartenkunst. 10: 50. Retrieved 17 June 2016.
  7. ↑ Accessions book. Royal Botanic Garden Edinburgh. 1902. pp. 45, 47.
  8. ↑ "List of Living Accessions: Ulmus". Royal Botanic Garden Edinburgh. Retrieved 21 September 2016.
  9. ↑ "European Elms" (PDF). Bulletin of popular information. Arnold Arboretum, Harvard University. 1 (14): 56. 23 July 1915. Retrieved 18 October 2016.
  10. ↑ Schoch, G. von (1900). "Baumpflanzungen in den städten". Die Gartenkunst. 2: 66. Retrieved 17 June 2016.
  11. ↑ Beterams, J (1911). "Nochmals die wertvollen Ulmen". Mitteilungen der Deutschen dendrologischen gesellschaft. 20: 249–250. Retrieved 17 June 2016.

External links

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