Higan Japanese flowering Cherry (Prunus subhirtella).
Higan cherry is a medium sized deciduous tree growing to 40-50-ft tall. It is a naturally occurring hybrid from Japan that generally features non-fragrant pale pink to white flowers in spring, pea-sized blackish fruits in late summer and ovate to lanceolate green leaves. Cold hardy to USDA zone 4-8. More pictures of Cherry Blossom at Cherry Gallery.
If you want more information about this flower, just search the plant's Latin name on Google: