White-flowered forms are quite common in the wild, and the name hardyi is usually used for them. Upright deciduous shrub. Younger stems and leaf stalks are maroon contrasting with glossy new growth. Lots of white flowers.
Hardy in all but the coldest parts of Pacific Northwest and UK, France and northern Italy, around Bergen (Norway) and mildest parts of NE USA such as Cape Cod and parts of Long Island.