A tree is a large, woody, perennial plant with one to several relatively massive trunks and an elevated crown. The boundary between a tree and a shrub is sometimes not that sharp. The tree in the foreground (or center) of this photo is an American elm (Ulmus americana ) during winter.
Photo of a magnificent tree at the Arnold Arboretum of Harvard University that unfortunately died of Dutch elm disease a year after this photo was taken; by K. R. Robertson.