French
DeutschUlmus minor 'Bea Schwarz'
| Ulmus minor 'Bea Schwarz' | |
|---|---|
_040606c.jpg) 'Bea Schwarz', Amsterdam. | |
| Cultivar | 'Bea Schwarz' |
| Origin | Netherlands |
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]).
Description
[edit]The leaves are ovoid to oval (6 to 10 cm), emerging more or less purple-red; the underside is pillose.[1][2] The tree is considered of poor growth and shape if grafted on U. × hollandica rootstock.[3] Nowadays it is sparsely grown on its own rootstock.
Pests and diseases
[edit]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
[edit]Commercial production was discontinued in the Netherlands soon after its release in 1948.[4][5][6] 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.[7][8]
!['Bea Schwarz' (left). Noordzijde, Sloterplas, Amsterdam, 2012.[9]](/wiki/en/File:Bea_Schwarz-iepen_bij_de_Sloterplas.jpg)
Notable trees
[edit]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.[10]
Hybrid cultivars
[edit]- 'Nanguen' = Lutèce, 'Clusius', 'Lobel', (all from crossings with clone '336', 'Bea Schwarz' selfed), Ulmus 'Amsterdam' (possibly from an open pollination of 'Bea Schwarz' and sometimes called Ulmus minor 'Amsterdam' in the Netherlands).[11]
Etymology
[edit]The tree is named for Bea Schwarz, the Dutch phytopathologist who identified the Asian microfungus known as Ophiostoma ulmi, one of the causative agents of Dutch elm disease, in the 1920s.
Accessions
[edit]North America
[edit]- Arnold Arboretum, US. Acc. nos. 151–61, 276–62
- Holden Arboretum, US. Acc. no. 57–1243
- Longwood Gardens, US. Acc. no. 1967–0876
Europe
[edit]- Brighton & Hove City Council, UK. NCCPG Elm Collection.[12]
- Grange Farm Arboretum, Lincolnshire, UK. Acc. no. 1275
- Netherlands Plant Collection Ulmus, Wijdemeren, North Holland, Netherlands, planted on its own rootstock 2019, Location Dennenlaan, Loosdrecht[13]
Nurseries
[edit]Europe
[edit]References
[edit]- ^ a b F. J., Fontaine (1968). "Ulmus". Dendroflora. 5: 37–55. Retrieved 30 August 2017.
- ^ "Herbarium specimen - L.1586828". Botany catalogues. Naturalis Biodiversity Center. Sheet labelled Ulmus 'Bea Schwarz', Baarn, 1948; "Herbarium specimen - L%20%200940206". Botany catalogues. Naturalis Biodiversity Center. Sheet labelled Ulmus 'Bea Schwarz', Baarn, 1949; "Herbarium specimen DOV0038308". Delaware State University, Claude E. Phillips Herbarium. Sheet labelled U. × hollandica 'Bea Schwarz'; leaves specimen; "Herbarium specimen DOV0038308". Delaware State University, Claude E. Phillips Herbarium. Sheet labelled U. × hollandica 'Bea Schwarz'; flowers specimen
- ^ Photograph of free-standing 'Bea Schwarz' elm, [1].
- ^ Heybroek, Hans M. (1983). Burdekin, D.A. (ed.). "Resistant elms for Europe" (PDF). Forestry Commission Bulletin (Research on Dutch Elm Disease in Europe) (60). London: HMSO: 108–113.
- ^ 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.
- ^ Went, J. C. (1954). Tijschr. Plantenziekten 60: 109-127, 1954.
- ^ Hillier & Sons (1977). Catalogue of Trees & Shrubs. Hillier, Ampfield, UK.
- ^ Hillier & Sons Sales inventory 1962 to 1977 (unpublished).
- ^ "Noordzijde near sloterplas". Retrieved 21 February 2019.
- ^ Johnson, O. (2011). Champion trees of Britain & Ireland, p.167. Kew Publishing, Kew London. ISBN 978-1-84246-452-6
- ^ Tijdgat, M. (2020): Ulmus – Gebruikswaarde- en sortimentsonderzoek in de praktijk. Dendroflora Nr. 56-2020, p.73 Koninklijke Vereniging voor Boskoopse Culturen & Nederlandse Dendrologische Vereniging
- ^ "List of plants in the {elm} collection". Brighton & Hove City Council. Retrieved 23 September 2016.
- ^ Netherlands Plant Collection: Iepen, Ulmus