The elm

Elm

Elms are deciduous and semi-deciduous trees comprising the genus Ulmus in the plant family Ulmaceae. The dozens of species are found in temperate and tropical-montane regions of North America and Eurasia, ranging southward into Indonesia. Elms are components of many kinds of natural forests...

 cultivar 'Bea Schwarz' was cloned (as No. 62) at Wageningen

Wageningen

' is a municipality and a historical town in the central Netherlands, in the province of Gelderland. It is famous for Wageningen University, which specializes in life sciences. The city has 37,414 inhabitants , of which many thousands are students...

, the Netherlands

Netherlands

The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...

 ostensibly from a selection of Ulmus minor found in France

France

The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

 in 1939. However, specimens of the tree grown in the UK and the USA are treated as cultivars of Ulmus × hollandica

Ulmus × hollandica

Ulmus × hollandica Mill. , often known simply as Dutch Elm, is a natural hybrid between Wych Elm Ulmus glabra and Field Elm Ulmus minor which commonly occurs across Europe wherever the ranges of the two parent species overlap. In England, according to the field-studies of R. H...

(after Fontaine ).

Pests and diseases

Moderately resistant to Dutch elm disease

Dutch elm disease

Dutch elm disease is a disease caused by a member of the sac fungi category, affecting elm trees which is spread by the elm bark beetle. Although believed to be originally native to Asia, the disease has been accidentally introduced into America and Europe, where it has devastated native...

, and more resistant to Coral Spot fungus Nectria cinnabarina

Nectria cinnabarina

Nectria cinnabarina is a plant pathogen that causes cankers on many tree species and also a disease known as coral spot.- External links :* *...

than its forebear 'Christine Buisman'

Ulmus 'Christine Buisman'

The elm cultivar Christine Buisman was the first release of the Dutch elmbreeding programme initiated in response to the less virulent form of Dutchelm disease , Ophiostoma ulmi, which afflicted Europe's elms after the First...

.

Cultivation

Commercial production was discontinued soon after its release in 1948. Nevertheless, its moderate resistance to Dutch elm disease

Dutch elm disease

Dutch elm disease is a disease caused by a member of the sac fungi category, affecting elm trees which is spread by the elm bark beetle. Although believed to be originally native to Asia, the disease has been accidentally introduced into America and Europe, where it has devastated native...

 saw it, or its selfed progeny, successfully used in later Dutch hybridizations, notably 'Nanguen' (Lutèce TM).

Hybrid cultivars

• 'Nanguen' (Lutèce TM), 'Clusius', 'Lobel', (both from crossings with 'Bea Schwarz' selfed), 'Amsterdam'
  Ulmus 'Amsterdam'
  Ulmus Amsterdam is a Dutch cultivar raised at the Huis Groeneveld in Baarn before 1950, possibly from an open pollination of the early Dutch cultivar 'Bea Schwarz', and introduced by Albert Hoekstra, former director of Amsterdam's horticulture department, .-Description:'Amsterdam' is a small tree,...
  
   (from an open pollination?).

Etymology

The tree is named for Bea Schwarz

Marie Beatrice Schol-Schwarz

Dr Marie Beatrice Schol-Schwarz was the Dutch phytopathologist, better known simply as Bea Schwarz, who discovered the causal fungus of Dutch elm disease whilst studying for her doctorate at the University of Utrecht in 1922, where she was Johanna Westerdijk's first PhD student.Born in Batavia,...

, the Dutch phytopathologist

Phytopathology

Plant pathology is the scientific study of plant diseases caused by pathogens and environmental conditions . Organisms that cause infectious disease include fungi, oomycetes, bacteria, viruses, viroids, virus-like organisms, phytoplasmas, protozoa, nematodes and parasitic plants...

 who identified Dutch elm disease in the 1920s.

North America

• Arnold Arboretum. Acc. nos. 151-61, 276-62
• Holden Arboretum
  Holden Arboretum
  The Holden Arboretum, in Kirtland, Ohio, USA, is one of the largest arboretums and botanical gardens in the United States, with over 3,500 acres , 600 acres of which are devoted to collections and gardens. Diverse natural areas and ecologically sensitive habitats make up the rest of the holdings...
  
  . Acc. no. 57-1243
• Longwood Gardens
  Longwood Gardens
  Longwood Gardens consists of over 1,077 acres of gardens, woodlands, and meadows in Kennett Square, Pennsylvania, United States in the Brandywine Creek Valley...
  
  . Acc. no. 1967-0876

Europe

• Brighton & Hove
  Brighton & Hove
  Brighton and Hove is a unitary authority area and city on the south coast of England. It is England's most populous seaside resort.In 1997 Brighton and Hove were joined to form the unitary authority of Brighton and Hove, which was granted city status by Queen Elizabeth II as part of the millennium...
  
   City Council, UK, NCCPG Elm Collection http://www.brighton-hove.gov.uk/index.cfm?request=c1108042. Crespin Way, Hollingdean
  Hollingdean
  Hollingdean is a part of the city of Brighton & Hove.Hollingdean is in effect the older part of Hollingbury south of the park. It is bounded by Ditchling Road to the west, the Round Hill area to the south, and Lewes Road and Moulsecoomb to the east...
  
   30 trees planted in 1964, and include the UK Champion, 22 m high, 33 cm d.b.h. in 1998. University of Sussex Student Residency, Lewes Road, Falmer (3 trees - 2007).