A tree by the water at Frear Park

There's a tree by the water at Frear Park with balls hanging from it, like a sycamore, but I don't think it's a sycamore.  What could it be?

It's always hard to get good pictures of bud patterns on twigs, but both the picture above and the one below show that the buds are alternate.

This close-up of an end bud shows it is reddish in color.  And it looks like it is starting to open.

The bark is speckled with white.