American elms used to be famous for the unusual vase shape of their crown. The spreading limbs and pendulous branchlets produced the fountaining effect. They certainly looked beautiful when bordering streets, but another valuable side of their cultivation was that elms did not obstruct vision for drivers, at the same time, producing nice and deep shade. The Flora of North America (v. 3, 1997) says "the species still exists in substantial numbers both as shade trees and in nature." Photo credit Luba Batuner