A native of Europe, Norway Maple (Acer platanoides) trees have been planted throughout New England. Often confused with Sugar Maple, a simple test can aide in sorting out these similarly leaved trees: when removed from a branch, Norway Maple leaf stalks typically exude white latex.
The leaves of Norway Maple emerge earlier in spring and are retained later into the fall than those of the native Sugar Maple. Norway Maple leaves also tend to be wider with more prominent outer lobes.
The flowers and fruit of these two trees are also different, but they aren't around as long as the leaves are for convenient comparison. However, the bark provides a year-round way to tell these two apart. Mature Norway Maples have bark with a criss-crossed pattern, similar to the native White Ash tree.
In the next Meet the Maples post, I'll profile the very different looking Silver Maple (Acer saccharinum).