Deutzia compacta SBEC 644 syn. hookeriana
This has grown into one of our favorite small deciduous shrubs which we grow near our bog garden. Collected in China on the Sino-British Expedition to Cangshan in 1981 which was one of the first western botanic expeditions to China in modern times. Copious pink-white flowers on a 4'-6' tall shrub. Zone 6 at least.