Guelder-Rose, gel'der-roz, a cultivated variety of viburnum. It is related to the high bush cranberry and is not a rose at all. The white flowers are barren. Instead of forming flat cymes, the blossoms are collected in a large globose head or ball. It is called usually the snowball tree. It is hardy, and is planted in lawns and other places for ornamental purposes. When in flower it is a handsome plant. The foliage is also attractive.