Ulmus americana 'Penn Treaty'
|Origin||Penn Treaty Park, Kensington, Philadelphia, USA|
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 from the Shackamaxon Treaty Elm (felled by a storm in 1810) in what was later named Penn Treaty Park, Kensington, Pa.
The 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.
Pests and diseases
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 gathered by the arboretum staff in autumn. The tree is not known to be in cultivation beyond North America, nor is it in commerce.
- 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.