Best for syrupAlso called Hard maple, Rock maple

Sugar maple

Acer saccharum

The gold standard — if you've got one, tap it first.

Mature sugar maple trunk with gray, vertical bark plates lifting and curling away at their edges — Photo: Famartin, CC BY-SA 4.0

Sugar maple twig tip in early March with a sharp-pointed brown terminal bud flanked by a pair of smaller buds — Photo: Tgalos90, CC BY-SA 4.0

Single green sugar maple leaf on a black background, five lobes with smooth, sparsely toothed edges — Photo: Gilles Ayotte (Université Laval botanical collection), CC BY-SA 4.0

Open-grown sugar maple with a full, rounded crown in orange-red fall color on a university lawn (fall color varies and isn't an ID feature) — Photo: Cephas, CC BY-SA 4.0

Identify it in winter

Opposite branching: buds and twigs come off in matched pairs — the first test for any maple.
Buds are brown, slender and very sharp-pointed, with tight scales; the tip bud is about ¼–⅜ inch long.
Twigs are brown, slender and shiny, dotted with pale lenticels.
Mature bark is gray-brown and furrowed into long, thick, irregular plates that curl outward along one edge. Trunks under about 4–8 inches are still smooth and gray.
Forest trees grow tall and straight; open-grown trees make a dense, oval crown.

In summer

Leaves 3–6 inches wide with 5 rounded lobes and smooth edges — no fine teeth, which quickly rules out red and silver maple.
Snap off a leaf stem and the sap is clear, not milky (milky means Norway maple).
Winged seeds hang in horseshoe-shaped pairs and ripen in fall.

Easily confused with

Norway maple

Norway's buds are fat, rounded and green-to-purple (sugar maple's are slim, sharp and brown), and its bark has tight interlacing ridges instead of curling plates. In summer its leaf stems bleed milky sap.

Red maple

Red maple's buds are short, blunt and red on reddish twigs; sugar maple's are sharp and brown.

Black maple

Nearly identical and just as good to tap. Look for drooping, often 3-lobed leaves with small leafy stipules where the leaf stem meets the twig.

Oaks

Oaks branch alternately and carry a cluster of buds at each twig tip; maples pair up.

Sap sugar: About 2–2.5% on average; plenty of trees run 3% or more
Season: Sugar maple wakes up late in spring, so its sap stays good longer than red or silver maple's. Tap when days reach about 40°F and nights still freeze; you're done when the buds swell and the sap turns “buddy.”
Syrup: The benchmark maple flavor. At 2% sugar it takes about 43 gallons of sap to make one gallon of syrup — the sugarmaker's “Rule of 86” (86 ÷ sap sugar % = gallons of sap).
Range: Northeastern North America: Nova Scotia and southern Quebec west to southeast Manitoba and Minnesota, south through the Appalachians to Tennessee and west into Missouri.

Tapping it?

Sources

Sugar Maple (Acer saccharum) — Godman, Yawney & Tubbs — USDA Forest Service — Silvics of North America (Agriculture Handbook 654, 1990)
North American Maple Syrup Producers Manual, 2nd ed. (Bulletin 856) — Ch. 3 “The Maple Resource” and Ch. 7 “Rule of 86” — Ohio State University Extension with the North American Maple Syrup Council
Sugar maple (Acer saccharum) — Virginia Tech Dendrology Fact Sheet — Virginia Tech Dendrology (Dept. of Forest Resources & Environmental Conservation)
Distinguishing Between Norway, Sugar, and Black Maples — Purdue University Extension
Bulletin #7036: How to Tap Maple Trees and Make Maple Syrup — University of Maine Cooperative Extension

Other trees

Red maple Silver maple Black maple Norway maple Boxelder Paper birch Black walnut

Keep this season's numbers for next year

LuckySap logs every collection with its sugar reading and your notes, then lines this season up against the last. Free on iPhone.