Hydrangea arborescens, commonly known as smooth hydrangea, wild hydrangea, or sevenbark, is a species of flowering plant in the family Hydrangeaceae. It is a small- to medium-sized, deciduous shrub up to 3m (10 ft) tall that is native to the eastern United States.
Smooth hydrangea is widely distributed across the eastern United States – from southern New York to the panhandle of Florida, west to eastern Oklahoma and south-eastern Kansas. It is mainly found in moist soils under a hardwood forest canopy and is often common along woodland road banks and streams. It is common in the Delaware River Valley and in the Appalachian Mountains.