Leaf: Opposite, pinnately compound, 3 to 5 leaflets (sometimes 7), 2 to 4 inches long, margin coarsely serrate or somewhat lobed, shape variable but leaflets often resemble a classic maple leaf, light green above and paler below.
Flower: Species is dioecious; yellow-green, in drooping racemes; appearing in spring.
Fruit: Paired V-shaped samaras, 1 to 1 1/2 inches long, in drooping clusters,light tan when ripe in fall, persist throughout winter.
Twig: Green to purplish green, moderately stout, leaf scars narrow, meeting in raised points, often covered with a glaucous bloom; buds white and hairy, lateral buds appressed.
Bark: Thin, gray to light brown, with shallow interlacing ridges; young bark is generally warty.
Form: Medium sized tree to 60 feet, typically with poor form and multiple trunks; sprouts often occur on bole.

Notes:

Leaf: Opposite, simple, palmately-veined, 5 to 7 lobed with long pointed teeth", dark green above, paler below; exudes milky white sap from the petiole when detached. A purple (nearly black) leaf variety known as Crimson King is widely planted.
Flower: Species is dioecious; bright yellow-green in color and somewhat showy, appearing in the spring before the leaves.
Fruit: Widely divergent 2-winged samaras, 1 1/2 to 2 inches long in clusters, relatively flat seed cavity, mature in late summer and persist into the winter.
Twig: Stout, brown with a large, turban-shaped buds that are initially green maturing to purple.
Bark: Gray-brown, a bit corky, on older trees shallowly furrowed with long narrow, somewhat interlacing ridges.
Form: Medium sized tree to 80 feet tall, usually with a dense rounded crown.

Notes:

Leaf: Opposite, simple with 5 deeply palmate sinuses, lobe margins coarsely serrate, 2 1/2 to 5 inches long; light green above, pale, silvery white below.
Flower: Species is monoecious; greenish to reddish flowers appear in dense clusters in early spring long before leaves.
Fruit: Samara, largest of any native maple, divergent wings 1 1/2 to 2 1/2 inches long, germinate as soon as released, mature in late spring.
Twig: Similar to red maple but stouter and often more chestnut-brown in color, unpleasant odor when crushed; buds reddish brown with large scales, flower buds often in conspicuous dense clusters.
Bark: Light gray and smooth when young, when older breaks up into long thin strips, loose at ends. Similar to red maple but coarser.
Form: Can become quite a large tree reaching over 100 feet tall, trunk usually short, dividing into several subtrunks. Long slender branches sweep downward and then curve gracefully upwards.

Notes:

Leaf: Alternate, simple, obovate to oblong, 5 to 11 inches long, 2 to 3 inches wide, green above and below. Green pepper odor when crushed.
Flower: Species is monoecious; purplish-brown, broad bell shape, 6 petals, 1 to 1 1/2 inch across; appearing with or slightly before the leaves.
Fruit: Very unique in that they resemble a short, fat banana, 2 1/2 to 4 inches long, at first green then tuning yellowish then brown as they ripen in the fall; very fleshy and tastes much like a banana.
Twig: Moderately stout, red-brown; buds purplish brown, fuzzy, naked bud which is flattened and often curved, terminal bud 1/4 to 1/2 inch long.
Bark: Smooth, brown, splotched with wart-like lenticels, often with light gray patches.
Form: A small tree up to 40 feet tall, 12 inches in diameter, often found in growing in small clusters.

Notes:

Leaf: Alternate, simple, pinnately veined, oblong to obovate in shape with an entire margin, 3 to 5 inches long, occasionally shallow lobes (or coarse teeth) near tip, dark green above and slightly paler below.
Flower: Species is usually dioecious; not showy, light green in color, in clusters hanging from slender stalks, appearing with the leaves.
Fruit: A dark, purplish blue drupe, 1/2 inch long, with a fleshy coating surrounding a ribbed pit, ripen in late summer and fall.
Twig: Moderately stout, red-brown to gray, diaphragmed pith; 1 to 2 inch curved spur shoots are often present; buds ovate, pointed, green and light brown, but darkening to brown in the winter.
Bark: Gray-brown and shallowly, irregularly furrowed, on old stems it can become quite blocky, resembling alligator hide.
Form: A medium sized tree reaching up to 80 feet tall on moist sites, generally much shorter in the mountains. On younger trees the branches often stand at right angles to the trunk with numerous short, curled spur shoots present.

Notes:

Leaf: Opposite, deciduous, linear, one inch long, flat, generally appearing two-ranked in a flattened display; when growing on deciduous branchlets the leaf/deciduous branchlet structure resembles a feathery pinnately (or bi-pinnately) compound leaf, green to yellow-green.
Flower: Species is monoecious; males, light yellow brown, in narrow hanging clusters up to 12 inches long; females, yellow-green, solitary and erect with fused scales.
Fruit: Four-sided, box-like cones that hang on long stalks, round to cylindrical in shape, 1/2 to 1 inch long, light brown; peltate shields contain small, winged seeds, matures in late fall.
Twig: May be deciduous or not; non-deciduous twigs are slender, light reddish brown in color, smooth, with short, buff colored, opposite, cylindrical buds protruding at right angles; deciduous twigs are two-ranked, resembling pinnately compound leaves.
Bark: Reddish brown, fibrous and stringy, develops an irregular fluted pattern, exfoliates in strips, rope-like in appearance.
Form: Very straight, single trunk with numerous branches forming a narrow conical crown; capable of reaching heights well over 100 feet tall.

Notes:

Leaf: Alternate, simple, elliptical to oblong-ovate, 2 1/2 to 5 1/2 inches long, pinnately-veined, 11-14 pairs of veins, with each vein ending in a sharp distinct tooth, shiny green above, very waxy and smooth, slightly paler below.
Flower: Species is monoecious; male flowers borne on globose heads hanging from a slender 1 inch stalk, female flowers borne on shorter spikes, appearing just after leaves in the spring.
Fruit: Nuts are irregularly triangular, shiny brown and edible, found in pairs within a woody husk covered with spines, 1/2 to 3/4 inch long, maturing in the fall.
Twig: Very slender, zigzag, light brown in color; buds are long (3/4 inch), light brown, and slender, covered with overlapping scales (best described as "cigar-shaped"), widely divergent from the stems, almost looking like long thorns.
Bark: The bark is smooth, thin, and gray in color even on the largest stems. Beech bark diseases severely deforms the smooth bark.
Form: A medium to large tree up to 100 feet tall with a rounded crown. Often found in thickets produced by root suckering. Old trees may be surrounded by a ring of young beech.

Notes:

Leaf: Alternate, simple, ovate or elliptical, 2 to 4 inches long, pinnately-veined (7 to 9 pairs), with a nearly entire to somewhat toothed or wavy margin. Fine hairs present on margin with tomentum on veins. Shiny green in color, but purple varieties are planted.
Flower: Species is monoecious; male flowers borne on globose heads hanging from a slender stalk, female flowers borne on shorter spikes. Flowers appear just after leaves in the spring.
Fruit: Nuts are irregularly triangular, shiny brown and edible, found in pairs within a woody husk covered with spines, 1 inch long, maturing in the fall.
Twig: Slender, zigzag, light brown in color; buds are long (1 inch), light brown, and slender, covered with overlapping scales that are tinged with tomentum, widely divergent from stems.
Bark: Smooth, thin, and dark gray-blue in color, smooth even on the largest stems, may be mottled.
Form: A medium size tree reaching up to 90 feet tall with a stocky trunk and a round crown.

Notes:

Leaf: Alternate, simple, palmately veined, orbicular, 4 to 6 inches across with 5 to 7 lobes (look like stars), and a finely serrate margin. Shiny green above and pubescent in the axils of the veins below, fragrant when crushed.
Flower: Species is monoecious; females borne on a slender stalk, capped with a globose head, male flowers borne on an upright raceme; both are small, bright yellow-green (tinged with red) and not showy, appear in early to mid-spring.
Fruit: Easy to identify spiny "gumballs", woody brown spherical cluster of capsules, 1 to 1 1/2 inches in diameter with openings in the surface that release 2 seeds from each capsule; maturing in fall.
Twig: Medium textured, shiny green to yellow-brown, usually with apparent corky outgrowths, particularly when fast growing. The terminal bud is large and is usually sticky, covered with green to orange-brown, shiny scales.
Bark: Gray-brown, irregular furrows and rough rounded ridges.
Form: A medium to large tree to 80 feet tall with a straight stem and a pyramidal crown, especially when young.

Notes:

Leaf: Alternate, simple, ovate to elliptical, entire, 3 to 6 inches long, pinnately veined and variably lobed, green above and below and fragrant when crushed; leaves may be unlobed, 2-lobed (resemble a mitten), or 3-lobed (resemble a trident), and all three shapes may be present on the same branch.
Flower: Species is dioecious; small but quite showy, both male and females are bright yellow-green, borne in 2 inch racemes appearing in early to mid-spring.
Fruit: Dark shiny blue, ovoid, fleshy drupes (1/3 inch long) that are borne in a red cup attached to a red stalks, held upright, maturing late summer.
Twig: Slender, green and sometimes pubescent, with a spicy-sweet aroma when broken; buds are 1/4 inch long and green; twigs from young plants displayed at a uniform 60 degree angle from main stem.
Bark: Brown, with cinnamon-brown inner bark, becoming coarsely ridged and furrowed; when cut the spicy aroma is obvious.
Form: Small to medium sized tree up to 60 feet tall with an irregular often twisted trunk and main branches, usually flat-topped crown; root suckering may result in thickets.

Notes:

Leaf: Alternate, simple, 2 to 5 inches long, oval to obovate, serrated margin (slightly rounded teeth), obvious darkened glands on petiole, generally with more than 8 pairs of veins.
Flower: Showy, white, 1 inch across, 3 to 5 per cluster, appearing early spring.
Fruit: Sweet, dark red to nearly black drupe, 1/2 to 1 inch across, may be clustered on spur shoots; matures early to mid summer.
Twig: Medium textured, gray-brown, with a mild bitter almond taste; buds large (up to 1/4 inch), reddish brown; spur shoots present with multiple terminal buds.
Bark: Gray-brown, smooth, with prominant, long horizontal lenticels, often peels.
Form: A small to medium sized tree, generally to 50 feet, with a broadly rounded crown.

Notes:

Leaf: Alternate, simple, orbicular to ovate, 3 to 4 inches long, pinnately veined, large blunt teeth, petiole flattened vetically, green above and paler below.
Flower: Species is dioecious; males and females occur on hanging, 2 to 3 inch long fuzzy catkins, appearing before the leaves in early spring.
Fruit: Cottony seeds, 1/4 inch long, borne in small dehiscent capsules that occur along catkins, maturing late spring to early summer.
Twig: Medium-textured, gray-brown in color; buds are ovate, pointed, red-brown to gray with some pubescence; leaf scars raised and heart-shaped. When chewed, the twig has a bitter, aspirin taste.
Bark: Thin, gray, olive-green to milky green and smooth on young stems; later gray-brown, ridged with diamond shaped lenticels and splits forming.
Form: A medium sized tree with an irregular, thin crown and a straight bole.

Notes:

Leaf: Alternate, simple, very narrowly lance-shaped, finely serrated margin, yellow-green above, milky green below, 3 to 6 inches in length, 3/8 to 1/2 inch in width.
Flower: Species is dioecious; males and females appear as upright catkins and are quite fuzzy, 1 inch long, appearing before or with the leaves.
Fruit: A one inch long cluster of valve-like capsules, light brown in color containing many fine, cottony seeds, ripen in late May to early June.
Twig: Very slender, smooth, olive-green to pale yellowish brown, hanging or drooping for long distances, almost rope-like; buds are small, appressed and covered by a single, cap-like scale. Terminal buds lacking.
Bark: Grayish brown and irregularly furrowed.
Form: Easily identified due to their long, graceful branches that sweep towards the ground. Crown is usually round, attaining a height of 40 to 50 feet.

Notes:

Leaf: Alternate, simple, pinnately veined, lanceolate in shape, 3 to 6 inches long, with a finely serrate margin. Leaves are dark and shiny above, light green below.
Flower: Species is dioecious; flowers are tiny, green, borne on catkins, 1 to 3 inches long, early summer.
Fruit: Cone-shaped capsules that contain many small, cottony seeds, borne on catkins; capsules split at maturity, mid summer.
Twig: Slender, orange-brown in color, with a bitter aspirin taste; buds are small and appressed, covered by one bud scale, the terminal bud absent; stipules/scars are obvious.
Bark: Brown to gray-black, with thick, somewhat scaly ridges and deep furrows.
Form: A small to medium sized tree that can develop a massive trunk with a spreading, irregular crown. Black willows are often affected by crown gall, and witches brooms and trunk sprouting are common.

Notes: