Seven Barks, Hydrangea arborescens, is also known as American Hydrangea and White Hydrangea. An elegent shrub, so named because of the unusual bark, peeling away from the trunk in sponatenous quills. A mild diuretic and urinary antiseptic, the bark of the roots has long been used to prevent and expel stones of the bladder and kidney. Seven Batks is a perennial shrub native to the eastern part of North America. It prefers partial shade in a moist soil, growing to about 2 metres. Round clusters of creamy white flowers occur in late spring and early summer.