Ulmus americana 'Penn Treaty'

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Ulmus americana
Cultivar
'Penn Treaty'
Origin
Penn Treaty Park, Kensington, Philadelphia, USA

'Penn Treaty' is a cultivar of the American Elm Ulmus americana, discovered in the Plant Sciences Data Center of the American Horticultural Society. Plants under that name were raised at the Morris Arboretum, Pennsylvania, Philadelphia, from grafts made in 1945 from a tree at Haverford College, itself a graft from the Shackamaxon Treaty Elm (felled by a storm in 1810) in what was later named Penn Treaty Park, Kensington, Pa.^[1].

This Haverford elm [1] was felled in 1977 after it had succumbed to Dutch elm disease. Planted in 1840, it measured 90 ft (28 m) in height, with a crown diameter of 120 ft (37 m) one hundred years later. Cuttings were taken in 1915, although all but one of the resultant trees have also died, the survivor still thrives (2006) at Barclay Beach. Moreover, a specimen raised from seed survives on Founder's Green, Haverford College, and is perpetuated by selfed seedlings assiduously gathered by the arboretum staff in autumn. The tree is not known to have been introduced to Europe or Australasia, nor is it commercially available from nurseries.