The weeping willow (Salix babylonica) is probably the best known of the weeping trees, with gracefully arching stems that dangle delicately and shiver in the breeze. The leaves of this deciduous tree are lance-shaped and grow 3 to 6 inches long; they turn yellow in the fall before dropping. The weeping willow's bark is rough and gray, with long, deep ridges. When the tree blooms in late winter or spring, yellow catkins (flowers) appear. Weeping willows are fast-growing trees, adding up to 10 feet per year when young, but their average lifespan is a relatively short 30 years.