Dutch elm disease (resistance)
European and North American elms are susceptible to Dutch elm disease, while Asian elms are more or less resistant. Cultivars bred in Holland for resistance to the first epidemic involved crosses among European taxa only, which proved to be susceptible in the second epidemic. Cultivars with Himalayan elm (U. wallichiana) in their parentage have proved to have some resistance in Europe, including U. ‘Nanguen’ LUTÈCE, while in the US crosses between European taxa and the Siberian elm (U. pumila) are said to be promising.