Example Key

1a. Seeds borne in woody (rarely fleshy) cones; leaves needlelike or overlapping (like fish scales),
      persistent in winter (coniferous tree).

2a. Leaves brownish-green, less than 2" long.

      3a. Cones fleshy; leaves overlapping..................................................Brown cedar

      3b. Cones woody; leaves needlelike..................................................Brown pine

2b. Leaves bluish-green, 2" long or greater.

      4a. Cones less than 8" long, leaves 3" - 4" long..................................False blue pine

      4b. Cones 8" - 12" long; leaves greater than 6" long.................Blue pine

1b. Seeds not borne in cones; leaves broad and flat absent in winter (deciduous tree).

SUGAR MAPLE or hard maple (Acer saccharum)
Large tree, 40' - 70' (80') tall; broad, round or oval crown; trunk up to 36" diameter.

Leaves: Opposite, simple, 3½" - 5½" long, nearly as wide, palmately lobed; lobes: 5 (rarely 3), rounded crotches, smooth or wavy margins; light green; yellow, orange, or deep red in autumn.

Twigs: Reddish-brown to gray with scattered whitish dots (lenticels); buds, reddish-brown to dark brown, cone-shaped, pointed tip, numerous scales.

Fruit: Samara, ¾"- 1¼" long, U-shaped pairs with nearly parallel wings, mature in autumn.

Bark: Light gray, smooth or warty; becoming dark gray to nearly black with deep, irregular furrows and narrow plates that curl at the edges, sometimes scaly.

Range Native, eastern Minnesota; hardy to Zone 3b.

Remarks: Very shade-tolerant; slow-growing; long-lived. Attractive, widely planted ornamental tree naturally found on moist, fertile soils. Primary source of maple syrup and maple sugar. Principal timber species; its hard, closely grained, light brown wood is used in furniture, flooring, cabinets, cutting boards, veneer, and musical instruments. Occasionally develops unique wood grain pattern known as bird's eye, curly, tiger, or blister maple.

Sugar Maple

BLACK MAPLE (Acer nigrum)
Large tree, nearly identical to sugar maple.

Leaves: 3-lobed (rarely 5), smooth or wavy margins, abruptly pointed lobes, drooping sides, dark green.

Range: Native, southeastern and south-central Minnesota; hardy to Zone 4a.

Black Maple

RED MAPLE or soft maple (Acer rubrum)
Medium to large tree, 40'- 70' tall; dense, rounded crown; trunk up to 24" diameter.

Leaves: Opposite, simple, 2½" - 4" long, nearly as wide, palmately lobed; lobes, 3 or 5 (usually 3), relatively shallow crotches (often pointed); doubly toothed margins; light green; scarlet red, orange, or yellow in autumn; red leafstalk.

Twigs: Bright red to reddish-brown with white dots (lenticels); buds, green or dark red, blunt.

Fruit: Samara, ½" - 1" long, U-shaped pairs with slightly divergent wings, mature in spring.

Bark: Silvery gray, smooth, scaly limb scars; breaking up into large, vertical strips with scaly ridges.

Range: Native and hardy throughout Minnesota except along western and southern border.

Remarks: Intermediate in shade-tolerance; moderately fast-growing; moderately long-lived. Attractive, hardy tree found on a broad range of site conditions. Tannins boiled from the bark formerly used to produce inks and cinnamon-colored dyes. Important ornamental species that also is sometimes used for maple syrup. Common name, red maple, is based on the color of the tree's flowers, not on its leaves.

Red Maple

SILVER MAPLE or soft maple (Acer saccharinum)
Large tree, 40' - 70' tall; massive, round-topped crown; trunk, often divided low, up to 42" diameter.

Leaves: Opposite, simple, 4" - 6" long, nearly as wide, palmately lobed; lobes, 5, 2 deeply cut crotches come to sharp point, doubly toothed margins; dull green (white or silvery below); pale yellow to orange in autumn.

Twigs: Yellowish-gray to reddish-brown, disagreeable odor when broken; buds, dark red, blunt.

Fruit: Samara, 1½" - 2½" long, V-shaped pairs with widely divergent wings, mature in spring.

Bark: Gray; smooth; becoming furrowed with long, scaly, narrow strips that often curl at the ends.

Range: Native, southern and east-central Minnesota, north to Duluth and west to upper Mississippi River; hardy to Zone 3b.

Remarks: Moderately shade-intolerant; fast-growing; moderately short-lived. Prolific seed producer commonly found in moist bottomland forests. Sprouts vigorously when injured. Extensively planted as a fast-growing street tree that is somewhat tolerant of extreme site conditions, but has brittle branches and roots that may damage sidewalks, sewers, and drains. Occasionally used for maple syrup.

Silver Maple

MOUNTAIN MAPLE (Acer spicatum)
Shrub or small tree, 10' - 20' (30') tall; small, irregular crown of upright branches; trunk, often crooked and divided, up to 7" diameter.

Leaves: Opposite, simple, 2½" - 4½" long, two-thirds as wide, palmately lobed; lobes, 3 (rarely 5), shallow crotches, coarsely toothed margins; light green; deep red or orange in autumn.

Twigs: Yellowish-green to reddish-green with velvety, gray hairs; terminal buds, red, perched on a small stalk, 2 scales.

Fruit: Samara, ¾" - 1" long, U-shaped pairs with divergent wings, mature in autumn.

Bark: Reddish-brown to brown, thin, smooth or slightly furrowed.

Range: Native, northeastern and east-central Minnesota; hardy throughout.

Remarks: Shade-tolerant; slow-growing; short-lived. Understory species found in moist, cool, often rocky forests. Live lower branches sprout roots and form new trees when covered by soil or plant litter.

Mountain Maple

NORWAY MAPLE (Acer platanoides)
Medium tree, 40' - 60' tall; dense, round crown; trunk up to 24" diameter.

Leaves: Opposite, simple, 4½" - 7" wide, nearly as long, exudes milky sap when cut, palmately lobed; lobes, 5, shallow crotches, sharp wavy-toothed margins; shiny green; bright yellow or orange-brown in autumn.

Twigs: Greenish-brown to brown; buds, yellowish-green to brownish-red, exude milky sap when cut.

Fruit: Samara, 1½" - 2" long, V-shaped pairs with extremely divergent wings, flat, mature in autumn.

Bark: Dark gray, smooth; becoming closely fissured with narrow, interlacing ridges.

Range: Introduced from Europe and western Asia; hardy to Zone 4a.

Remarks: Shade-tolerant, moderate-growing, moderately long-lived. Extensively planted ornamental street tree. Varieties with red or purple foliage often are planted, but are not always winter hardy in Minnesota.

Norway Maple

AMUR MAPLE (Acer ginnala)
Shrub or small tree, 15' - 18' tall; round to irregular crown; trunk, often multistemmed, up to 12".

Leaves: Opposite, simple, 1½" - 3" long, usually less than one-third as wide, palmately lobed with doubly toothed margins, middle lobe much larger than lateral lobes; dark green; bright red or orange in autumn.

Twigs: Yellowish-brown, slightly angled; buds, reddish-brown, small (1/8" long).

Fruit: Samara, 1" long, U-shaped pairs with nearly parallel wings, mature in autumn.

Bark: Grayish-brown, smooth; becoming vertically striped.

Range: Introduced from China and Japan; hardy to Zone 3a.

Remarks: Shade-tolerant; moderate growth rate; moderately long-lived. Attractive ornamental that requires a well-drained soil. Commonly planted in above-ground containers.

Amur Maple

TATARIAN MAPLE (Acer tataricum)
Shrub or small tree, very similar to amur maple.

Leaves: Doubly toothed or obscurely lobed margins.

Fruit: Samara, 11/3" - 1¾" long.

Range: Introduced from Europe; hardy to Zone 3a.

Tatarian Maple