Diameter represents tree height
You can view the location of street trees throughout New York City via the filters on the right sidebar.
If you click on a tree, you view see what it looks like on the street and see the estimated diameter at breast height.
The buttons along the bottom of the map toggle other layers.
Repeated clicking of tree dots may cause you to run over your personal Street View quota. If you wait long enough, this will reset. A correct API implementation is forthcoming.
The views are generated from data provided by the NYC Parks Department.
Species info has been loaded from Encyclopedia of Life.
These are some of the people who worked on this.