Ulmus 'Frontier' (original) (raw)

Ulmus 'Frontier' is an American hybrid cultivar [4], a United States National Arboretum introduction (NA 55393) derived from a crossing of the European Field Elm Ulmus minor (female parent) with the Chinese Elm Ulmus parvifolia in 1971. Released in 1990, the tree is a rare example of the hybridization of spring- and autumn-flowering elms. Tested in the US National Elm Trial coordinated by Colorado State University, [5] 'Frontier' averaged a survival rate of 74% after 10 years.