Species and cultivar | Number of trees | Species distribution and/or origin of cultivar | Cold hardiness rating |
---|---|---|---|
Carpinus betulus ‘Fastigiata’ | 6/2 | Species native to Central, Eastern, and Southern Europe to Western Asia; the cultivar ‘Fastigiata’ was introduced by the German arborist Hermann Hesse in pre-1893. | (4) 5 |
Crataegus monogyna ‘Stricta’ | 3 | Species native to Europe, Northwestern Africa, and Western Asia; the cultivar ‘Stricta’ was introduced by Ronald’s nursery, Brentford, England, in 1838. | 4 |
Ginkgo biloba | 2 | Species native to Southern China; planted as seed-propagated nursery stock from Sweden. | 4 |
Malus baccata ‘Columnaris’ + Malus baccata ‘Pyramidalis’ | 6/3 | Species native to Northern China, Sakhalin, Korea; the cultivar ‘Columnaris’ was introduced by the Arnold Arboretum, USA, in 1940; the trees shipped with the incorrect cultivar name ‘Pyramidalis’ are assumed to represent the cultivar ‘Street Parade,’ introduced in the Netherlands in 1982. | 3 |
Pterocarya fraxinifolia | 3 | Species native to Caucasus and Iran; propagated by seed from a selected Swedish E provenance. | (5) 6 |
Quercus palustris | 3 | Species native to Eastern USA; planted as seed-propagated Swedish nursery stock. | 4 |
Sorbus aucuparia | 6/3 | Species native to Middle and Northern Europe, Siberia, and Western Asia; planted as a vegetatively propagated, columnar clone originating from Southern Finland. | 3 |