Leaf: Alternate, simple, pinnately veined, oval to broadly lanceolate, 3 to 5 inches long, with a doubly serrate margin, green above, paler and fuzzy in the axils of veins and on the petiole.
Flower: Species is monoecious; males are preformed catkins, 1/2 to 1 inches long, in clusters of 3's (resemble birds toes), present throughout the winter; females appear in spring and are slender, light green catkins, 1/2 inch long, appearing or elongating (males) in spring.
Fruit: Very distinctive, resembling hops. More specifically, a 1/4 inch nutlet is enclosed in a dried, leafy, inflated sac. Several sacs hang from one stem, 1 1/2 to 2 1/2 inches long; maturing in late summer and persisting through winter.
Twig: Slender, reddish brown, smooth, and may be slightly pubescent. Male catkins present on the end of the branch; buds are small, plump ovate, and covered with green and red-brown, finely grooved (vertically) scales.
Bark: When young smooth, reddish brown, with horizontal lenticels (cherry like), later turning light brown and developing a shreddy appearance, broken into small plates or loose scales that are easily broken off with a brush of the hand.
Form: A small tree up to 40 feet tall that develops a round crown of fine branches.

Notes:

Leaf: Opposite, simple, elliptical in shape, very finely serrate, 1 to 3 inches long, pinnately veined, with a reddish petiole and often reddish leaf edges; dark green above and paler below.
Flower: Very attractive, small, white (buttery looking from a distance), appearing in dense slightly rounded panicles, 2 to 4 inches wide, appearing in mid-spring.
Fruit: Dark blue, elliptical drupes, 1/4 inch long, often with a whitish bloom, in hanging clusters and ripe in late summer, shriveled raisen-like fruits often persist into winter.
Twig: Moderately stout and stiff looking, reddish brown, numerous opposite short twigs give an appearance of a fish skeleton; buds are valvate, narrowly ovate, pinkish brown, and leathery looking; flower buds similar but swollen, appearing to have swallowed a BB.
Bark: Gray-brown and breaking up into small square plates - like alligator hide.
Form: A large shrub or small tree up to 20 feet with a twisted trunk and stiff, arching branches. Branches often have numerous short shoots that are obviously opposite and right-angled, resembling a fish skeleton.

Notes:

Leaf: Alternate, pinnately compound, with 7 to 19 leaflets, 8 to 14 inches long. Leaflets are oval, one inch long, with entire margins. Leaves resemble sprigs of grapes; green above and paler below.
Flower: Perfect, showy and fragrant, white, 1 inch long and pea-like, borne in long (5 inches) hanging clusters, appear in mid to late spring.
Fruit: Flattened legume, light brown, 2 to 4 inches long; containing 4 to 8 kidney-shaped, smooth, red-brown seeds, ripen in the fall.
Twig: Zigzag, somewhat stout and angular, red-brown in color, numerous lighter lenticels. Paired spines at each leaf scar (often absent on older or slow growing twigs); buds are submerged beneath the leaf scar.
Bark: Gray or light brown, thick and fibrous, heavily ridged and furrowed, resembles a woven rope.
Form: A medium sized tree to 70 feet, with a relatively straight trunk and a crown of crooked branches. Often forms thickets by root suckering.

Notes:

Leaf: Alternate, simple, obovate or oblong, large coarse gland tipped teeth on margin, 4 to 7 inches long, dark, shiny green above, much paler below.
Flower: Species is monoecious; male flowers are yellow-green long catkins (3 to 4 inches long); females are green to reddish, very small in leaf axils, appearing with the leaves.
Fruit: Acorn, nut 1/2 to 1 inch long, broadest below the middle, thin bowl-shaped cap covers about 1/3 of acorn and forms a tattered fringe on the margin of cap, dark brown when mature.
Twig: Slender to moderate, orange-brown, buds cluster at branch tips, terminal buds 1/8 inch long, pointed, chestnut brown, individual scales with frosted edges.
Bark: Thin, light gray, rough and flaky.
Form: Medium sized tree to 60 feet, with a rounded crown.

Notes:

Leaf: Alternate, simple, 5 to 8 inches long, oblong in shape with 7 to 11 bristle-tipped lobes, sinuses extend 1/3 to 1/2 of the way to midvein, generally very uniform in shape, dull green to blue-green above and paler below.
Flower: Species is monoecious; males in yellow-green slender, hanging catkins, 2 to 4 inches long; females are borne on short axiliary spikes, appearing with the leaves in spring.
Fruit: Acorns are 3/4 to 1 inch long and nearly round; cap is flat and thick, covering about 1/4 or less of the acorn, resembling a beret; matures in 2 growing seasons, in late summer and fall.
Twig: Quite stout, red-brown and glabrous; terminal buds multiple, quite large, conical, and covered with red-brown, mostly hairless scales but terminal scales may bear some frosty pubescence.
Bark: On young stems, smooth; older bark develops wide, flat-topped ridges and shallow furrows. The shallow furrows form a pattern resembling ski tracts.
Form: A medium sized to large tree that reaches up to 90 feet tall, develops a short trunk and round crown when open grown, straight with a clear, long bole when grown with competition.

Notes:

Leaf: Alternate, pinnately compound, 12 to 24 inches long with 10 to 24 leaflets (poorly formed or missing terminal leaflet), leaflets are ovate-lanceolate, finely serrate, and 3 to 3 1/2 inches long, rachis is stout and somewhat pubescent; yellow-green to green above, slightly paler below.
Flower: Species is monoecious; males are single-stemmed catkins, 2 1/2 to 5 1/2 inches long; females on short spikes near twig end, yellow-green in color, appearing in late spring.
Fruit: Round, 2 to 2 1/2 inches across, with a thick, green indehiscent husk. The husk contains an irregularly furrowed, hard nut that contains sweet, oily meat (edible), mature in late summer to fall.
Twig: Stout, light brown, with a buff-colored chambered pith; buds are tan, and large with a few pubescent scales; leaf scars are 3-lobed, resembling a "monkey face".
Bark: Brown on surface, darker brown when cut, ridged and furrowed with a rough diamond pattern.
Form: A medium to large tree up to 100 feet in height that developes a straight, clear bole with a narrow crown under competition, twigs and branches quite stout.

Notes:

Leaf: Alternate, simple, elliptical, 3 to 5 inches long, pinnately veined, entire margin that may be somewhat ciliate, strong, spicy odor when crushed, green above and slightly paler below.
Flower: Species is dioecious; small, but due to large numbers they can be showy, yellow, appearing in axillary clusters before the leaves in early spring.
Fruit: A bright red drupe when ripe (green before ripening), 3/8 inch long with a large seed and a peppery taste and scent, maturing in fall.
Twig: Slender, olive-green to brown in color, numerous light lenticels, with distinctive, stalked globose buds covered with 2 to 3 yellow-green to brown scales; when broken, a spicy, peppery smell is obvious.
Bark: Brown to gray-brown and speckled with light colored lenticels.
Form: A large shrub with several stems, usually rounded in outline up to 15 feet tall.

Notes:

Leaf: Alternate, simple, elliptical or ovate, 6 to 10 inches long, pinnately veined, entire margin, acuminate tip, dark green above and paler, whitened below.
Flower: Species is monoecious; 2 1/2 to 3 inches long, high in the tree, green to greenish-yellow, appearing in late spring or early summer.
Fruit: An aggregate of follicles, 2 to 3 inches long, cylindrical, initially green (cucumber-like), then red, and later dark brown; seeds inside follicles are 1/2 inch long, nearly round, red when mature in the fall.
Twig: Moderately stout, red-brown, light lenticels; large, silky, white terminal bud, stipule scars encircle the twig. Twigs have a spicy-sweet smell when broken.
Bark: Light gray-brown and flaky, quite soft (can dent with thumbnail), much darker reddish brown when flaked away.
Form: Pyramidal when young, developing a straight trunk and a rounded crown reaching up to 80 feet tall.

Notes:

Leaf: Opposite, pinnately compound with 7 serrate to entire leaflets that are ovate to somewhat lanceolate, 8 to 12 inches long, essentially hairless, green above and slightly paler below.
Flower: Species is dioecious; light green to purplish, both sexes lacking petals, females occuring in loose panicles, males in tighter clusters, appear after the leaves unfold.
Fruit: A one-winged, dry, flattened samara with a full, rounded, seed cavity, maturing in fall and dispersing over winter.
Twig: Stout, gray-olive-green, hairless, leaf scars round at the bottom, notched at the top, with lateral buds in the notch; terminal bud is large, brown, with leathery scales and flanked by two lateral buds.
Bark: Ashy gray to brown in color, with interlacing corky ridges forming obvious diamonds; older trees may be scaly.
Form: A large tree up to 80 feet tall that typically develops a straight, clear bole (particularly on good sites), usually with a narrow oblong crown.

Notes:

Leaf: Evergreen needles, 1 1/2 to 3 inches long, with 2 yellow-green, twisted, somewhat divergent needles per fascicle.
Flower: Species is monoecious; males cylindrical, yellow, near branch tip; females yellow to red, curved prickle present.
Fruit: Conical to ovoid cones are 1 1/2 to 2 1/2 inches long, sessile and persistent, with red-brown scales and an umbo armed with a sharp, needle-like prickle, maturing in the fall.
Twig: Slender, green changing to purple-green with a glaucous bloom; buds gray-brown, narrowly ovoid.
Bark: Orange-brown and scaly on young trees; older stems develop thin, small, scaly plates, cinnamon colored patches often on upper parts of trunk.
Form: A small to medium sized tree reaching up to 70 feet tall, eventually develops a flat top sparse crown; dead, gray (sharply angled upwards) branch stubs are almost always present along the trunk.

Notes:

Leaf: Alternate, simple, heart-shaped to ovate with a finely serrated margin, 2 to 3 inches in length, shiny green above, paler and dull below.
Flower: Large (2 to 4 inches across) clusters of showy white flowers each 1/2 to 3/4 inch across, appearing before or with the leaves; often so densely flowering that the entire tree appears white.
Fruit: Small (1/2 inch diameter), round, brown pome, very bitter.
Twig: Glossy brown to reddish brown, medium in texture, spur shoots present; terminal buds are large (1/4 to 1/2 inch long), ovate, and covered in light brown wooly hairs.
Bark: At first smooth with numerous lenticels, light brown to reddish brown, becoming grayish brown with shallow furrows and scaly ridges.
Form: Typically quite upright and conical with very narrow branch angles. May reach 60 feet in height.

Notes: