This post is perhaps a week late, but I have posted enough photos of Black Locust (Robinia pseudoacacia) bark, that it seemed remiss not to post a blossom.
These trees have been in bloom along highways and abandoned spaces for about two weeks. The flower structure is pretty typical for a Fabaeceous plant (or a Legume).
I read recently that this family is the third biggest flowering plant family, succeeding the Orchid (Orchidaceae) and Sunflower (Asteraceae) families.
This particular tree is on Chrystie and Stanton.