Willows are pioneer, sun loving trees that are the first to become established on sand bars.
Only black willow reaches commercial size. The bark of the root is intensely bitter and has been used as an ingredient of tonics to purge the blood. Usually black willow is a rather small tree, but under good conditions it may grow to 70 or 80 feet in height and two or more feet in diameter. Willow trees are either male or female with flowers of different sexes borne on seperate trees. The female flower hangs in long clusters or aments.