Tosa spirea 'Snowmound' (Spirea nipponica Snowmound)

Spiraea are deciduous shrubs, sometimes suckering, with simple leaves and short racemes, panicles or corymbs of small, 5-petalled white or pink flowers in spring or summer
 
'Snowmound' is a spreading medium-sized deciduous shrub with arching branches bearing small obovate leaves and short lateral shoots ending in rounded clusters, to 4cm in width, of small white flowers