Norway maple vs sugar maple: how to tell them apart

Leaves: lobes, teeth and color

Count the lobes on a few sun leaves. Purdue gives Norway maple 5 to 7 lobes, commonly 7, and sugar maple 5. Virginia Tech describes Norway maple lobes as having long pointed teeth, and sugar maple's as five delicately rounded lobes with an entire (smooth) margin between the points. Purdue adds that Norway maple leaves are generally broader than long, and Morton calls them slightly broader than sugar maple's.

Minnesota Wildflowers points out two more clues: Norway maple leaves are generally larger, with sharper points that are longer and more tapering, and both surfaces are darker green. Turn a leaf over: Purdue notes small hairs in the vein angles beneath a Norway maple leaf.

If the leaves are deep purple all summer, you have a Norway maple cultivar such as Crimson King, which Virginia Tech calls widely planted. The leaf color hides the shape comparison, but the milky sap is still there.

Seeds, flowers and buds

The samaras are the easiest clue to spot from the ground in summer. Purdue compares Norway maple seed pairs to a handlebar mustache, spread nearly horizontally, and sugar maple pairs to a mustache pointing downward. Virginia Tech gives 1 1/2 to 2 inches for Norway maple samaras and about 1 inch for sugar maple's, which turn brown when mature in fall. More helicopter seeds are compared in the guide to trees with helicopter seeds.

In spring, Norway maple flowers are bright yellow-green and somewhat showy, opening before the leaves, according to Virginia Tech; Morton describes them in upright, rounded clusters. Sugar maple flowers hang on slender stalks 1 to 3 inches long.

In winter, look at the end bud. Virginia Tech describes Norway maple's as large and turban-shaped, green maturing to purple, on a stout twig. Sugar maple's are brown, very sharp-pointed with tight scales, on a slender, shiny twig. The same bud test separates sugar maple from red maple, as the red maple vs sugar maple page shows.

Fall color and leaf drop

Fall gives a hint from across the street. Morton describes sugar maple fall color as brilliant yellow to burnt orange, and up to red. Norway maple ranges from yellow-green to yellow. Minnesota Wildflowers adds that Norway maple color is usually weak and that its leaves often hang on until late-season frosts before turning a drab olive brown. A maple still green while its neighbors are bare is worth a sap test. Other gold trees are sorted in trees with yellow leaves in fall.

Why it matters: an invasive look-alike

Norway maple is native to Europe and Asia, according to Morton, which finds it through much of the eastern United States, the West Coast and the northwestern states, and calls it an invasive plant. Purdue reports that it was introduced to America in the late 1700s, that George Washington reportedly bought two in 1792 for Mount Vernon, and that the Indiana Invasive Species Council found it far more shade-tolerant than sugar maple, letting it out-compete the native tree for light. Its thick canopy shades out the plants beneath.

Sugar maple, by contrast, is the tree Purdue describes as prized for its sugary sap. If you plan to tap trees, the identification has to be right first.

Tree Identifier can name either maple from one photo of a leaf or the samaras, and both species are in the app's Collection. Because a photo cannot show sap, use the snap test to confirm, then save the tree to the Tree Map so you can find your sugar maples again when the leaves are gone. The maple identification page covers silver, red, boxelder and bigleaf maple as well.