Leaves: Simple, opposite, 5-lobed, very deep spaces between lobes, teeth coarse; about 5″ in diameter, silvery below.

Twigs: Green in early spring, turning orange-brown, with many light colored dots (lenticels). Distinctive odor when broken. Buds of two distinct types: the small pointed leaf buds toward end of twig, and rounded, clustered flower buds below. Lower branches with up-turned tips.

Fruit: Largest of the native maples; wings may be 2″ long, curving inwards; matures in spring.

General: Bark on young trees smooth and gray; on older trees broken into long, narrow loose strips. A medium-sized tree usually found along streams. Sometimes planted as a shade tree. Wood has uses similar to those of red maple. This species is classed as a soft maple.

Leaves: Simple, opposite, generally 7-lobed, 4½″-5″ in diameter. Milky sap is evident after breaking the leaf stem. Leaves are heavier and thicker than those of sugar maple.

Twigs: Stout, reddish brown. Buds red and green, blunt; end bud much larger than side ones; bud scales with keel-like ridges.

Fruit: Wings wide-spreading, larger than those of sugar maple. Matures in autumn.

General: Bark on young tree light brown, smooth; on older trees it becomes closely fissured but not scaly, dark in color. A tree of medium-size. Imported from Europe and planted extensively as a street tree. The leaves are often attacked by an aphid insect which produces quantities of a sticky substance, spotting vehicles and sidewalks. This species is classed as a soft maple.

Leaves: Compound, alternate; leaflets 11 to 17, each 3″-5″ long, small-toothed; dark yellow-green above, paler, hairy below. End leaflet same size as side leaflets. Main leaf-stem with conspicuous sticky hairs. One of the last trees to unfold its leaves in spring, and the first to shed them in autumn.

Twigs: Stout, greenish-gray to tan, rough, brittle. Pith chocolate-brown, chambered. Buds light brown, hairy, not covered with scales; end bud ½″-¾″ long, side buds smaller. Fringe of short hairs between leaf-scar and bud.

Fruit: An oblong nut, 1½″-2½″ long, covered with a hairy, sticky husk. Nut pointed at one end, shell rough, oily kernel sweet.

General: Bark on young trunks rather smooth, light-gray; later darker, deeply furrowed with wide, smooth, flat-topped ridges. A small to medium-sized tree. Wood used chiefly for furniture, instrument cases, and boxes. Also called white walnut.

Leaves: Compound, alternate; leaflets 15 to 23, each 3″-4″ long, small-toothed; dark yellow-green above, paler, hairy below. End leaflet absent or very small. Main leaf-stem with very fine hairs.

Twigs: Stout, orange-brown to dark brown, roughened by large leaf scars, easily broken; pith pale brown, chambered. Buds gray, downy; side buds ⅙″ long, end bud larger.

Fruit: A round nut, 1″-2″ in diameter, shell rough, covered with a thick, almost smooth, green spongy husk; oily kernel sweet. Flowers in drooping green catkins, appearing with the unfolding leaves, which is also true of butternut.

General: Bark dark brown to gray-black, with narrow ridges. A large-sized tree, found locally on rich soils mainly in the southern part of the State. Wood valuable for quality furniture, veneer, gun stocks and musical instruments.

Leaves: Compound, alternate; leaflets usually 5, each 4″ to 7″ long, the lower pair smallest, margins fine-toothed; fragrant when crushed. Larger than those of pignut hickory, with which it is sometimes confused.

Twigs: Stout, often hairy, gray-brown to reddish brown, with numerous light spots (lenticels). Buds large, with 3-4 outer dark brown, loosely fitting, nearly smooth scales; inner scales velvety; end buds ½″-¾″ long.

Fruit: Nearly round, 1″-2½″ in diameter; husk thick, splits into 4 pieces when ripe; nut white, 4-ridged, pointed at one end, usually thin-shelled; kernel sweet.

General: Bark at first smooth and gray, soon breaking into long and loosely-attached plates that gives the trunk a shaggy appearance. A medium-sized tree found on a variety of sites but most common on good soils; grows slowly. Wood used principally for tool handles. The wood of all hickories is valuable to the farmer for fuel and smoking meat.

Leaves: Compound, alternate; leaflets usually 7, each 4″-7″ long, hairy beneath, margins fine-toothed. Dried leaf-stems often cling all winter.

Twigs: Somewhat stouter than shagbark hickory, usually hairy, often angled, orange-brown, with numerous orange spots (lenticels). Buds very large, with 6-8 outer dark brown, loosely fitting keeled scales; end buds ¾″-1″ long. Prominent orange-colored leaf scars.

Fruit: Nearly round to almost egg-shaped, 1¾″-2¾″ long; husk thick, splits into 4 pieces when ripe; nut yellowish white to reddish brown, 4- to 6-ridged, pointed at both ends, usually thick-shelled; kernel sweet. Flowers appear in catkins, as do all the hickories, when leaves are mature.

General: Bark like that of shagbark hickory but often with straighter plates (less shaggy). A medium-sized tree that prefers wet soils. Wood has same uses as shagbark hickory.

Leaves: Compound, alternate; leaf-stems with fine hairs; leaflets 7 to 9, each 4″-8″ long, margins finely to coarsely toothed; golden glandular dots beneath; very fragrant when crushed.

Twigs: Stout, hairy, reddish brown to brownish gray, with numerous pale spots (lenticels). Buds large, egg-shaped, with 3-5 outer yellowish brown, densely hairy scales; end buds ½″-¾″ long. Leaf scars distinctly 3-lobed.

Fruit: Nearly round to egg-shaped, 1½″-2″ long; husk thick, splits into 4 pieces when ripe; nut reddish brown, slightly ridged, thick-shelled; kernel sweet.

General: Bark gray to dark gray, tight; irregularly shallow-fissured when older. A medium-sized tree found mostly in the southern part of the State. Wood has same uses as shagbark hickory.

Leaves: Compound, alternate; leaflets usually 5, each 3″-6″ long; margins fine-toothed. Entire leaf smooth. Averages smaller than shagbark hickory.

Twigs: Medium-stout, not hairy, reddish brown, with numerous pale spots (lenticels). Buds egg-shaped and pointed, smallest of the native hickories, with more than 6 scales; outer scales often fall off during the winter, end buds ¼″-½″ long.

Fruit: Usually pear-shaped, 1″-2½″ long; husk thin, remains closed or splits partly when ripe; nut brownish white, not ridged, usually thick-shelled; kernel sweet but with bitter after-taste.

General: Bark gray to dark gray, usually tight; shallow fissured when older. A medium-sized tree of drier locations. Wood has same uses as shagbark hickory.

Leaves: Compound, alternate; leaf-stem slender, somewhat downy; leaflets 7-11, each 3″-6″ long, narrow margins finely to coarsely toothed.

Twigs: Medium-stout, smooth, orange-green to gray-brown, with numerous pale spots (lenticels). Buds covered with 4 sulphur-yellow, gland-dotted scales, end buds ⅓″-¾″ long, flattened.

Fruit: Nearly round, ¾″-1½″ in diameter; husk thin, yellowish gland-dotted, splits about to the middle into 4 sections when ripe; nut light reddish brown or gray-brown, not ridged, thin-shelled; kernel with red-brown skin, bitter.

General: Bark gray, tight; remains rather smooth for many years; with narrow ridges when older. A medium-sized tree, usually found near streams; grows more rapidly and its wood is lighter than any of the other native hickories. Wood has same uses as shagbark hickory.

Leaves: Simple, alternate, about 3½″ long, unevenly saw-toothed; dull green above, yellow-green beneath, with some white hairs at the points where veins join; usually heart-shaped at the base.

Twigs: Green and somewhat downy when young, becoming red-brown, smooth and shiny. Strong wintergreen flavor. Buds reddish brown, sharp-pointed, shiny.

Fruit: A very small winged nut. These nuts, together with small scales, form a cone-like structure about 1½″ long. Sketch shows twig in spring with male and female flowers. All birches have similar fruiting structures.

General: Bark on young trees dark reddish brown, tight, marked with pale horizontal lines (lenticels), resembling bark of young black cherry; becoming black and breaking into large plates. Medium-sized tree. Wood used chiefly for furniture, boxes, and other containers. Distillation of the bark and twigs produces “oil-of-wintergreen.” Also known as black birch.

Leaves: Simple, alternate; similar to sweet birch but base usually rounded.

Twigs: Like sweet birch but paler, and more downy when young. Wintergreen flavor faint. Buds slightly downy, dull, yellowish brown. Sketch shows winter twig with lateral buds and partially grown female flowers.

Fruit: Similar to sweet birch.

General: Bark on very young trees golden gray, shiny; later yellow, forming ragged ends which curl and can be readily peeled in thin, narrow strips, highly inflammable, and ideal to start a fire under wet conditions. On very old trunks bark becomes darker, coarse and platy. A medium to large tree. Found mostly in the northern part of the State. Wood principally used for furniture, interior finish, boxes and other containers.

Leaves: Simple, alternate, 1½″-3″ long, dark green above, yellow-green below, wedge-shaped at the base, margins usually with large teeth.

Twigs: Slender, at first greenish and hairy, later turning reddish brown, smooth; with pale horizontal lines (lenticels). Buds sharp-pointed and shiny, smooth or slightly fuzzy.

Fruit: Similar to sweet birch.

General: Bark reddish brown or cinnamon, peeling off in curled, shaggy strips; on older trunks becoming dark colored and rough. Medium-sized tree; found almost entirely along the lower reaches of our larger streams. Wood lighter, softer, and less valuable than sweet birch and yellow birch.

Leaves: Simple, alternate, 2″-3″ long, oval, sharply toothed, dark green above, lighter below.

Twigs: At early age greenish and fuzzy, later turning dark gray; irregularly marked with raised orange colored dots (lenticels). Buds dark brown, sticky. Immature male catkins at the ends of the twigs in autumn and winter, as is true of all the birches.

Fruit: Similar to sweet birch. Mature in July.

General: Bark creamy, to chalky white, peeling easily. Once the bark is removed, it is not renewed. A small to medium-sized tree. Often found with several stems growing together, occurring naturally only in the northern part of the State. Also called canoe birch and white birch. Wood has uses similar to those of yellow birch, but principally used for spools, clothes-pins, toothpicks and paper pulp.

Leaves: Simple, alternate, triangular in shape, with long tapering point, 2½″-3″ long, smooth above and below, tremulous. Leaf-stems very slender. Turn yellow in autumn, as is true of all birches.

Twigs: Slender, greenish brown, rough due to small warty glands. Buds sharp-pointed, gummy.

Fruit: Similar to sweet birch but shorter (¾″ long).

General: Bark dull white, not peeling into thin paper-like layers as is the case with paper birch; dark colored on the branches; orange inner bark. Usually with triangular-shaped black patches on the trunk. A small short-lived tree, usually growing in clumps. Occurs chiefly in the northeastern counties. Wood of little commercial value; chiefly used for fuel.

Leaves: Compound, alternate; leaflets 1″-2″ long, margins smooth.

Twigs: Angled, somewhat zigzag, brittle, with short stout prickles; no end bud, side buds small and hidden in winter.

Fruit: A thin, flat pod, 2″-4″ long; usually with 4-8 seeds; splits into halves when ripe. Flowers white, showy, very fragrant in drooping clusters, appearing in May and June.

General: Bark rough, furrowed, thick. A medium-sized tree. Often seen along farm fences and roads. Wood is durable in contact with the soil and in demand for posts, poles, railroad ties, and mine timbers. Unfortunately, several insects and wood rots often cause heavy damage, especially to trees on poor soils.

Leaves: Compound and doubly-compound, alternate; leaf-stem grooved above, hairy; leaflets 1″ long, usually fine-toothed on margins.

Twigs: Medium stout, shiny, greenish brown to reddish brown, zigzag, smooth, often with long branched thorns; no end bud, very small side buds.

Fruit: A leathery pod, 10″-18″ long, flat, usually twisted, with numerous seeds; often of high sugar content; eaten by some animals. Does not split into 2 halves, as does the pod of black locust.

General: Bark on young trees greenish brown with many long, raised, horizontal lines (lenticels); later brown to nearly black, fissured and with thick plates. A medium-sized tree; usually found as a native near streams; also planted as a shade tree. Branched thorns on the trunk and limbs make it easy to identify in winter. There is a thornless variety. Wood is mainly used for fence posts, general construction, and furniture.

Leaves: Compound, opposite; leaflets 5-9, each 3″-5″ long, stalked, somewhat silvery beneath; margins entire or with few rounded teeth toward the tip.

Twigs: Stout, usually smooth, gray-brown, with few large pale spots (lenticels). Buds blunt, dark brown. Leaf scars half-circular but notched at top.

Fruit: A winged seed, 1″-2″ long, ¼″ wide, shaped like a canoe paddle, in hanging clusters which often remain attached for several months after ripening in autumn.

General: Bark gray-brown, with diamond-shaped fissures when older. A large tree; trunk usually long and straight; commonly occurring on rich soils. Wood important for such special uses as handles, vehicle parts and athletic equipment (practically all baseball bats); valuable for curved parts in furniture.

Leaves: Compound, opposite; leaflets 7-11, each 3″-5″ long, not stalked except end one, dark green above, lighter green beneath with some rusty hairs; margins saw-toothed.

Twigs: Stout, at first somewhat hairy, becoming smooth, gray or red-brown, with many large pale spots (lenticels). Buds dark brown to black, end bud pointed. Leaf scars nearly circular, with raised margins; not notched at the top.

Fruit: Resembles that of white ash but is usually smaller (1″-1¾″ long and ⅜″ wide).

General: Bark grayish, when older becoming corky-ridged or scaly; knobs frequent on the trunk. A medium-sized tree that prefers cool, swampy sites. Wood is generally lighter in weight and weaker than white ash but used for the same purposes.

Leaves: Simple, alternate, 4″-6″ in diameter, generally 4-lobed, bright green, turning yellow in autumn.

Twigs: In spring and summer, green, sometimes with purplish tinge; during winter reddish brown, smooth, shiny. Buds large, smooth, flattened, “duck-billed.”

Fruit: At first green, turning light brown when ripe in autumn; cone-like, 2½″-3″ long, made up of winged seeds. Greenish yellow tulip-like flowers in May or June.

General: Bark at first dark green and smooth; whitish vertical streaks soon appearing; later dark gray and furrowed. A large tree, the tallest of the eastern hardwoods. It grows rapidly and is an important timber and shade tree. The wood is valuable for veneer and many other uses. Also known as tulip poplar.

Leaves: Simple, alternate, 4″-12″ long, smooth above, downy beneath; margins smooth or sometimes wavy.

Twigs: Reddish brown, shiny, with peppery smell and taste. Buds covered with greenish white silky hairs; end buds ½″-¾″ long. Leaf scars horseshoe shaped.

Fruit: When young, like a small green cucumber. When mature in autumn, 3″-4″ long, a cluster of small red pods, each containing two scarlet seeds; often remains attached all winter. Flowers large (3″ long), greenish yellow, single, upright; appear from April to June.

General: Bark gray-brown to brown, developing long narrow furrows and loose scaly ridges. A medium-sized tree, found mainly in the western half of the State. Wood used mainly for interior finish, furniture and containers.

Leaves: Simple, alternate, 4″-6″ long, unequal at the base, rather rough on the upper surface; usually soft-hairy below; veins prominent; margin coarsely toothed. Leaf-stem short.

Twigs: Slender, zigzag, brown, smooth or slightly hairy. Leaf buds ⅛″-¼″ long, flattened. Flower buds larger, below leaf buds. Bud scales red-brown, smooth or downy; margins dark.

Fruit: A seed surrounded by an oval, thin papery wing, ½″ long, deeply notched at the tip; ripening in spring and borne in clusters; wing with scattered hairs along margin. Flowers and fruit appear before the leaves, as is true of slippery elm.

General: Bark dark gray to gray-brown, with long corky ridges; on older trees separated by diamond-shaped fissures. A large and highly prized shade tree. The drooping crown often gives it a vase-shaped appearance. Found locally throughout Pennsylvania, mainly on moist areas. The hard, tough wood has many uses, including the manufacture of boxes, barrels and furniture.

Leaves: Simple, alternate, 5″-7″ long; usually larger than those of American elm, rough on both sides or soft-hairy below; margin coarsely toothed. Leaf-stem short.

Twigs: Stouter than on American elm, grayish and rather rough. Buds slightly larger than those of American elm, and more round—seldom flattened. Bud scales brown to almost black, rusty-haired.

Fruit: Like that of American elm but somewhat larger (¾″ long); wing margin not hairy and slightly notched at the tip.

General: Bark similar to American elm but of lighter color, softer, and fissures not diamond-shaped in outline. Inner bark sticky and fragrant. A medium-sized tree usually found near streams. Crown does not droop like that of American elm. The wood is commonly marketed with the preceding species.

Leaves: Simple, alternate, 2″-4″ long, slender pointed; margin sharp toothed; base unequal; often rough above, slightly hairy and veins prominent on undersides; 3-veined at base. Leaf-stem somewhat downy and grooved; fairly long (compared to elm).

Twigs: Slender, reddish brown, with chambered white pith. Buds small, sharp-pointed, closely pressed to the twig.

Fruit: Resembles a cherry, dark purple in color, ¼″-½″ diameter, sweet but with very little flesh covering the pitted stone; borne singly on a long slender stem; ripens in autumn.

General: Bark gray-brown with characteristic warty projections or irregular ridges. A small tree. “Witches-brooms” are common. Most common on limestone soils in moist locations. Sometimes mistaken for elm. Wood used principally for furniture, boxes and other containers.

Leaves: Simple, alternate, 1½″-3″ in diameter, light green, smooth above and below, nearly circular; margins with fine teeth; leaf-stems thin and flattened, causing the leaves to tremble in the slightest breeze. Yellowish-green when unfolding in spring.

Twigs: Slender, reddish brown, smooth, shiny. Pith star-shaped, white. Buds sharp-pointed, smooth, shiny, often curved inward.

Fruit: A small (¼″ long) capsule containing 10-12 seeds; capsules spirally arranged on a 4″ long drooping stalk, maturing in early summer. Each tiny cottony seed surrounded by long silky threads.

General: Bark thin, pale yellow-green to silvery gray when young, eventually becoming dark brown or gray and rough. A small to medium-sized tree, of rapid growth but short-lived. Often one of the first forest trees to become established on recently burned areas; the most widely distributed tree of North America. Most common in northern Pennsylvania. Wood used chiefly for paper pulp.

Leaves: Simple, alternate, 3″-4″ long, dark green above, paler below, margins with coarse teeth; leaf-stems flattened; silvery when unfolding in spring.

Twigs: Rather stout, brownish gray, sometimes with a coating of pale, wooly down. Buds blunt-pointed, dull, seldom curved, often wooly.

Fruit: Similar to quaking aspen. Flowers, in the form of hanging catkins, appear before the leaves in the spring, as is the case with quaking aspen.

General: Bark similar to that of quaking aspen, but usually darker. A small to medium-sized tree; short-lived. Most common in southern Pennsylvania. Wood used chiefly for paper pulp.

Leaves: Simple, alternate, long and narrow, short-stemmed, sharp pointed, fine teeth on the margin, average length 3″; dark green above, much lighter below. The stipules (“small leaves” at the base of leaf-stems of the main leaves) remain through most of the summer.

Twigs: Slender, brittle at the base, bright reddish brown to orange-green. Buds covered by a single scale, small, cone-shaped, sharp-pointed.

Fruit: Small brown capsule, ¼″ long, borne in long hanging clusters; ripens in May or June. Each tiny seed surrounded by tufts of long silky hair.

General: Bark thick, dark brown, separating into broad, flat plates or ridges as the tree grows older. A small to medium-sized tree. Only native willow which grows to a fair size. Found mainly in moist situations. Often several trunks arise from the same root system. Weeping willow (S. babylonica) and brittle willow (S. fragilis) are introduced trees often planted for ornamental purposes.

Leaves: Simple, alternate, narrow, with tapering tip, shiny above, paler below and usually with reddish brown hairs near the base; 2″-5″ long, margins with short incurved teeth.

Twigs: Smooth, reddish brown, often covered with a thin gray coating which peels or rubs off easily; bitter when chewed; with minute, rounded gray lenticels. Buds smooth, shiny, sharp-pointed, same color as twigs but often tinged with green.

Fruit: Round, black with a purplish tint, ⅓″-½″ in diameter, containing a single round, stony seed. Arranged in hanging clusters. Flowers white, in 4″-long upright clusters in June.

General: Bark on young trunks smooth, dark red-brown, marked with numerous raised horizontal lines (lenticels), somewhat resembling that of sweet birch; later breaking into thick irregular plates with upturned edges. A large tree in the northern part of the State; medium-sized in the southern counties. Wood used chiefly for quality furniture and interior finish.