Tags: Cultivar (Cultivated Variety).
‘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.