Along the same path on the Beach Avenue side of Alexandra Park where I posted a Sorbus megalocarpa, the Parks Board has planted three different dogwoods. How thoughtful is that for people who want to compare these things! Though a distinguishing feature of dogwoods is the opposite branching, the first two have sort-of alternate branching, or at least, not really opposite branching; they had tiny flowers in clusters, and they have smooth tiny round fruits. The first is Cornus alternifolia, the distinguishing feature of which are the brilliant red stems on the infructescences. This is Cornus controversa, a close relative of the previous one. In flower, these look a lot alike to some of us, but right now, they look totally different. These leaves seem larger, and the stems on the infructescences are almost lime green. The little round fruits will turn black or almost so, like on the other species, but there are more pronounced persistent pistils. I just made that up; maybe someone can describe that properly. It's too bad I don't have flower photos for this other dogwood, and the fruits are just forming. I have changed my guess to Cornus florida based on the white stems and petioles and what I think the fruit is going to look like. I don't feel very certain of this, though.
@wcutler, I see you have had no replies to this Wendy, so I looked it up in my old RHS encyclopedia and I would agree that it is Cornus Florida. flowering dogwood. Common name American boxwood.
C. alternifolia and C. controversa are both subg. Mesomora dogwoods. Cornus in Flora of North America @ efloras.org