I have a young tree (~4Y old), located in Toronto, Ontario, Canada. I do not know what type of tree it is, and would really like help identifying it. I seem to recall, but am not 100% on this, that the garden centre where I bought it said it was native to this region (I had asked them for something that would be hardy and not require too much special care).
Photos of the tree's flowers are below.
A related question I had asked shows photos of the trunk and leaves.