Ulmus minor 'Bea Schwarz'

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

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

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

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.[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' on the left with later replacements on the right. Noordzijde, Sloterplas, Amsterdam, 2012.[9]
    'Bea Schwarz' on the left with later replacements on the right. Noordzijde, Sloterplas, Amsterdam, 2012.[9]

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.[10]

Hybrid cultivars

  • '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

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

  • Noordplant [2], Glimmen, Netherlands.

References

  1. ^ a b F. J., Fontaine (1968). "Ulmus". Dendroflora. 5: 37–55. Retrieved 30 August 2017.
  2. ^ "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
  3. ^ Photograph of free-standing 'Bea Schwarz' elm, [1].
  4. ^ 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.
  5. ^ 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.
  6. ^ Went, J. C. (1954). Tijschr. Plantenziekten 60: 109-127, 1954.
  7. ^ Hillier & Sons (1977). Catalogue of Trees & Shrubs. Hillier, Ampfield, UK.
  8. ^ Hillier & Sons Sales inventory 1962 to 1977 (unpublished).
  9. ^ "Noordzijde near sloterplas". Retrieved 21 February 2019.
  10. ^ Johnson, O. (2011). Champion trees of Britain & Ireland, p.167. Kew Publishing, Kew London. ISBN 978-1-84246-452-6
  11. ^ Tijdgat, M. (2020): Ulmus – Gebruikswaarde- en sortimentsonderzoek in de praktijk. Dendroflora Nr. 56-2020, p.73 Koninklijke Vereniging voor Boskoopse Culturen & Nederlandse Dendrologische Vereniging
  12. ^ "List of plants in the {elm} collection". Brighton & Hove City Council. Retrieved 23 September 2016.
  13. ^ Netherlands Plant Collection: Iepen, Ulmus
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Species, varieties and subspecies
  • U. alata (Winged elm)
  • U. americana (American elm)
  • U. americana var. floridana (Florida elm)
  • U. bergmanniana (Bergmann's elm)
  • U. bergmanniana var. bergmanniana
  • U. bergmanniana var. lasiophylla
  • U. castaneifolia (Chestnut-leafed or multinerved elm)
  • U. changii (Hangzhou elm)
  • U. changii var. changii
  • U. changii var. kunmingensis (Kunming elm)
  • U. chenmoui (Chenmou or Langya Mountain elm)
  • U. chumlia
  • U. crassifolia (Cedar or Texas cedar elm)
  • U. davidiana (David or Father David elm)
  • U. davidiana var. davidiana
  • U. davidiana var. japonica (Japanese elm)
  • U. elongata (Long raceme elm)
  • U. gaussenii (Anhui or hairy elm)
  • U. glabra (Wych or scots elm)
  • U. glaucescens (Gansu elm)
  • U. glaucescens var. glaucescens
  • U. glaucescens var. lasiocarpa (hairy-fruited glaucescent elm)
  • U. harbinensis (Harbin elm)
  • U. ismaelis
  • U. laciniata (Manchurian cut-leaf or lobed elm)
  • U. laciniata var. nikkoensis (Nikko elm)
  • U. laevis (European white elm)
  • U. laevis var. celtidea
  • U. laevis var. parvifolia
  • U. laevis var. simplicidens
  • U. lamellosa (Hebei elm)
  • U. lanceifolia (Vietnam elm)
  • U. macrocarpa (Large-fruited elm)
  • U. macrocarpa var. glabra
  • U. macrocarpa var. macrocarpa
  • U. mexicana (Mexican elm)
  • U. microcarpa (Tibetan elm)
  • U. minor (Field elm)
  • U. minor subsp. minor
  • U. minor var. italica
  • U. parvifolia (Chinese or lacebark elm)
  • U. parvifolia var. coreana (Korean elm)
  • U. prunifolia (Cherry-leafed elm)
  • U. pseudopropinqua (Harbin spring elm)
  • U. pumila (Siberian elm)
  • U. rubra (Slippery elm)
  • U. serotina (September elm)
  • U. szechuanica (Szechuan (Sichuan) or red-fruited elm)
  • U. thomasii (Rock or cork elm)
  • U. uyematsui (Alishan elm)
  • U. villosa (Cherry-bark or marn elm)
  • U. wallichiana (Himalayan or kashmir elm)
  • U. wallichiana subsp. wallichiana
  • U. wallichiana subsp. xanthoderma
  • U. wallichiana var. tomentosa
Disputed species, varieties and subspecies
  • U. boissieri
  • U. minor subsp. canescens (Grey, grey-leafed or hoary elm)
  • U. elliptica
Hybrids
  • U. davidiana var. japonica × U. minor
  • U. × arbuscula
  • U. × arkansana
  • U. × brandisiana
  • U. × diversifolia
  • U. × hollandica (Dutch elm)
  • U. × hollandica var. insularum
  • U. × intermedia
  • U. × mesocarpa
Species cultivars
American elm
Cedar elm
Chinese elm
European white elm
Field elm
Japanese elm
Siberian elm
Winged elm
Wych elm
Hybrid cultivars
Dutch elm
U. × intermedia
Unconfirmed derivation cultivarsFossil elms
  • U. okanaganensis