National Tree of Ukraine
Viburnum is a genus of about 150–175 species of flowering plants in the moschatel family. The viburnum willow is also considered the national tree of Ukraine. This is according to Wikipedia. There are many types of willows of course. I have Boyd's willow as a bonsai which can be found at most any nursery in the Pacific Northwest. You can of course find willows at most any northern nursery too.