Ulmus americana 'Penn Treaty'

Elm cultivar
Ulmus americana 'Penn Treaty'
Scion of the Penn Treaty Elm at the Haverford College Arboretum, planted 1915 (2017)
SpeciesUlmus americana
Cultivar'Penn Treaty'
OriginPenn Treaty Park, Kensington, Philadelphia, US

The American Elm cultivar Ulmus americana 'Penn Treaty' was raised by the Plant Sciences Data Center of the American Horticultural Society. Plants under that name were propagated by the Morris Arboretum, Pennsylvania, Philadelphia, from grafts made in 1945 from a tree at Haverford College, itself a graft, planted in 1840, from the Shackamaxon Treaty Elm – the tree under which William Penn signed his treaty with Native Americans in 1682[1] (felled by a storm in 1810[2]) in what was later named Penn Treaty Park, Kensington, Pa.[3]

Description

The original "Treaty Elm," Birch's Views of Philadelphia (1800).

The first elm at Haverford, planted in 1840, measured 90 ft (28 m) in height, with a crown diameter of 120 ft (37 m) 100 years later. Its surviving scion in Haverford College Arboretum is an irregularly-branched elm, unlike most selected varieties of American elm.[4]

Pests and diseases

The 1840 Haverford elm was felled in 1977 after it had succumbed to Dutch elm disease.[5]

Cultivation

Cuttings from the 1840 Haverford elm were taken in 1915 by C. Cresson Wistar, an alumnus of Haverford College, and seven scions were planted behind Barclay Hall in the arboretum. Although all but one of the resultant trees have also died, the survivor still thrives (2017).[5] In addition, a specimen raised from seed survives on Founder's Green, Haverford College, and is perpetuated by selfed seedlings gathered by the arboretum staff in autumn. Katharine Stanley Nicholson in her Historic American trees (1922) recorded other 19th-century plantings of scions of the original tree.[2]

The tree is not known to be in cultivation beyond North America, nor is it in commerce.

Accessions

None known.

References

  1. ^ Nicholson, Katharine Stanley, Historic American trees (NY, 1922); p.38
  2. ^ a b Nicholson, Katharine Stanley, Historic American trees (NY, 1922); p.40
  3. ^ Santamour, Frank S.; Bentz, Susan E. (May 1995). "Updated Checklist of Elm (Ulmus) Cultivars for use in North America". Journal of Arboriculture. 21 (3): 122–131. Retrieved 20 June 2016.
  4. ^ Photograph of the surviving elm in Haverford College Arboretum; haverford.edu/arboretum/arboretum-highlights
  5. ^ a b 'Treaty Elm'; haverford.edu/arboretum/arboretum-highlights/treaty-elm
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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