Ulmus minor 'Bea Schwarz'

The elm cultivar Ulmus minor 'Bea Schwarz' was cloned (as No. 62) at Wageningen in the Netherlands, by the elm disease committee, from a selection of Ulmus minor found in France in 1939. However, specimens of the tree grown in the UK and the United States are falsely treated as Ulmus × hollandica (after Fontaine [1]).

Ulmus minor 'Bea Schwarz'
'Bea Schwarz', Amsterdam.
Cultivar'Bea Schwarz'
OriginNetherlands

Description

The tree is considered of poor growth and shape if grafted on U. × hollandica rootstock.[2] Nowadays it is sparsely grown on its own rootstock.

Pests and diseases

Not resistant to the second, more virulent, strain of Dutch elm disease, (O. novo-ulmi), but more resistant to Coral Spot fungus Nectria cinnabarina than its forebear 'Christine Buisman'.

Cultivation

Commercial production was discontinued in the Netherlands soon after its release in 1948.[3][4][5] Nevertheless, its moderate resistance to Dutch elm disease saw it, or its selfed progeny, successfully used in later Dutch hybridizations, notably 'Nanguen' = Lutèce. 'Bea Schwarz' was later propagated and marketed in the UK by the Hillier & Sons nursery, Winchester, Hampshire from 1967 to 1977, when production ceased with the advent of the more virulent form of Dutch elm disease.[6][7]

  • 'Bea Schwarz' on the left with later replacements on the right. Noordzijde, Sloterplas, Amsterdam, 2012.
    'Bea Schwarz' on the left with later replacements on the right. Noordzijde, Sloterplas, Amsterdam, 2012.[8]

Notable trees

The largest known examples in the UK grow along Crespin Way, Hollingdean, Brighton; planted in 1964, they measured 19 m high by 50 cm d.b.h. in 2009.[9]

Hybrid cultivars

Etymology

The tree is named for Bea Schwarz, the Dutch phytopathologist who identified the Asian fungus known as Dutch elm disease in the 1920s.

Accessions

North America

Europe

Nurseries

Europe

References
  1. F. J., Fontaine (1968). "Ulmus". Dendroflora. 5: 37–55. Retrieved 30 August 2017.
  2. Photograph of free-standing 'Bea Schwarz' elm, .
  3. Heybroek, Hans M. (1983). Burdekin, D.A. (ed.). "Resistant elms for Europe" (PDF). Forestry Commission Bulletin (Research on Dutch Elm Disease in Europe). London: HMSO (60): 108–113.
  4. Heybroek, H.M. (1993). "The Dutch Elm Breeding Program". In Sticklen, Mariam B.; Sherald, James L. (eds.). Dutch Elm Disease Research. New York, USA: Springer-Verlag. pp. 16–25. ISBN 978-1-4615-6874-2. Retrieved 26 October 2017.
  5. Went, J. C. (1954). Tijschr. Plantenziekten 60: 109-127, 1954.
  6. Hillier & Sons (1977). Catalogue of Trees & Shrubs. Hillier, Ampfield, UK.
  7. Hillier & Sons Sales inventory 1962 to 1977 (unpublished).
  8. "Noordzijde near sloterplas". Retrieved 21 February 2019.
  9. Johnson, O. (2011). Champion trees of Britain & Ireland, p.167. Kew Publishing, Kew London. ISBN 978-1-84246-452-6
  10. Tijdgat, M. (2020): Ulmus – Gebruikswaarde- en sortimentsonderzoek in de praktijk. Dendroflora Nr. 56-2020, p.73 Koninklijke Vereniging voor Boskoopse Culturen & Nederlandse Dendrologische Vereniging
  11. "List of plants in the {elm} collection". Brighton & Hove City Council. Retrieved 23 September 2016.
  12. Netherlands Plant Collection: Iepen, Ulmus

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