Ulmus 'Willis'

Ulmus hybrid
Hybrid parentage	U. pumila × U. rubra
Cultivar	'Willis'
Origin	USA

Ulmus 'Willis' is a hybrid elm cultivar which originated as a crossing made by a Mr Minnick of Kansas and treated simply as a hybrid. Almost certainly derived from a crossing of the Siberian Elm Ulmus pumila (female parent) and the Red Elm Ulmus rubra, it was originally believed that the male parent was the American Elm Ulmus americana.^[1]

Description

'Willis' was described as having a smooth grey bark, large leaves similar to U. americana, and capable of very rapid growth.^[1]

Pests and diseases

'Willis' has not been widely tested for resistance to Dutch elm disease.^[2]

Cultivation

First marketed by the Willis Nursery Co., Ottawa, Kansas, circa 1959,^[2] it is not known whether the cultivar remains in cultivation in the USA, nor whether it was ever introduced to Europe or Australasia.

References

1. Green, P. S. (1964). Registration of cultivar names in Ulmus. Arnoldia, Vol. 24. Arnold Arboretum, Harvard University.
2. Santamour, F. S., & Bentz, S. E. Updated checklist of elm (Ulmus) cultivars for use in North America. Journal of Arboriculture, 21(3): May, 1995