Ulmus × intermedia 'Coolshade'
| Ulmus × intermedia 'Coolshade' | |
|---|---|
| Hybrid parentage | U. rubra × U. pumila |
| Cultivar | 'Coolshade' |
| Origin | Sarcoxie, Missouri, USA |
The
Sarcoxie, Missouri, in 1946. At Arnold Arboretum, where there was a specimen, herbarium material was labelled Ulmus pumila 'Coolshade'.[1]
Description
'Coolshade' has rapid, stocky growth with a compact crown resistant to breakage under ice and snow. Its foliage is a very dark green.[2][3] There appears to be little evidence of Ulmus rubra ingression in the Arnold Arboretum 1960 leaves specimens labelled Ulmus pumila 'Coolshade', suggesting that its hybridity may have been questioned there.[4]
Pests and diseases
Reputedly tolerant of Dutch elm disease, 'Coolshade' has not been tested by inoculation to determine the degree of resistance.
Cultivation
'Coolshade' was raised to create a disease-resistant tree that would not suffer the storm damage frequently sustained by the weak-wooded U. pumila. The tree was introduced to the
UK
in the 1960s but no longer survives there.
Cultivars
- 'Improved Coolshade'
Accessions
North America
- Arnold Arboretum, US. Acc. no. 561–48
References
- ^ "Herbarium specimen - L.1582543". Botany catalogues. Naturalis Biodiversity Center. Sheet labelled U. pumila L. 'Coolshade' (Arnold Arboretum specimen 1, 1960); "Herbarium specimen - WAG.1911576". Botany catalogues. Naturalis Biodiversity Center. Sheet labelled U. pumila L. 'Coolshade' (Arnold Arboretum specimen 2, 1960)
- ^ Green, Peter Shaw (1964). "Registration of cultivar names in Ulmus". Arnoldia. 24 (6–8). Arnold Arboretum, Harvard University: 41–80. Retrieved 16 February 2017.
- ^ Bean, W. J. (1981). Trees and shrubs hardy in Great Britain, 7th edition. Murray, London.
- ^ bioportal.naturalis.nl, specimen L.1582543