This
genus consists of about 45 species of opposite
leaf shrubs and climbing vines native to
North
America and
Asia. The individual flowers are
small but they are borne in clusters of various
sizes. In the cluster are sterile "ray" flowers
on the outside and fertile flowers in the
center.
Viburnums
are closely related and
Viburnum opulus
and V. sargentii have similar types of
flowers.