Black Maple might as well be Sugar Maple. The leaf shape is a bit different, but that's about it. Maple syrup producers use the Black as well as the Sugar Maple and state that the sugar content is the same.
There are some other minor differences if you were to compare them side by side, but they interbreed and therefore there are a range of measurements and thicknesses and hairiness and other things that taxonomists use to create new species.
Black Maple has a smaller range, not reaching into the northeast and Canada like the Sugar Maple does. This suggests that there has been a bit of evolution. It's likely that two populations of the same species got separated geographically and evolved slightly different leaf shapes and then the populations got intermixed again. This makes taxonomists crazy because they didn't evolve enough to be completely different, but are different enough to deserve consideration, so they argue about whether they are two different species, two different sub-species, or just two different variations of the same species.
Notice that the center lobe of the Sugar Maple leaf has parallel edges, whereas the Black Maple's center lobe edges have a slope that makes it somewhat triangular. Also note that the edge of the Sugar Maple leaf has several teeth while the Black Maple has few or none.
|The bark of the older Black Maple tree is darker than the Sugar Maple|