MEDULLARY RAYS

CONDUCT FOOD AND WATER RADIALLY, SERVE IN FOOD STORAGE

PITH

ANNUAL RINGS

INDICATE GROWTH, NORMALLY ONE RING PER YEAR

LEAVES

THE AIR SUPPLIES CARBON, THE PRINCIPAL FOOD OF THE TREE, WHICH IS TAKEN IN ON THE UNDER SURFACE OF THE LEAVES.

HEARTWOOD (INACTIVE CELLS)

ADDS STRUCTURAL SUPPORT

SAPWOOD

CARRIES FOOD AND WATER UPWARD

CAMBIUM

GROWING LAYER, CELLS DIVIDE HERE TO FORM BOTH BARK AND WOOD.

INNER BARK

CARRIES FOOD MADE IN THE LEAVES DOWNWARD TO CAMBIUM AND STORAGE CELLS.

OUTER BARK

INACTIVE CELLS FORM PROTECTION FOR INNER BARK

SOIL

BACTERIA AND FUNGI MAKE AVAILABLE SOIL NUTRIENTS

ROOTS

ABSORB FOOD ELEMENTS THROUGH THE TINY ROOT HAIRS, ALSO PROVIDE ANCHORAGE

FOREWORD

The purpose of this booklet is to make the reader’s life more enjoyable by being able to identify, through leaf, twig and bark characteristics, the important trees of Pennsylvania at various seasons of the year.

Today, more than ever before, trees play an increasingly important part in our lives.

Trees produce wood, one of the essentials of our everyday life. The uses for wood are rapidly increasing.

Trees provide shade and solace for man; they help to beautify the places where we live; help purify the air we breathe and the water we drink; enrich the soil and retard the earth from sliding into our streams, and provide food and shelter for wildlife.

In a few words: Trees live to give.

We sincerely hope the brief study of tree features described in this publication will help you to develop a closer feeling for our mutual friends of the plant kingdom—the trees of our land.

COMMONWEALTH OF PENNSYLVANIA
Department of Environmental Resources
Harrisburg, 1971

INTRODUCTION

Pennsylvania, with its unique geographical position, has 102 kinds of trees native to the State, although there are numerous introduced species growing and thriving in this latitude and climate. In addition, at least 21 large native shrubs sometimes grow to tree size and form.

Less than half of these native trees are presently classified as important timber species. But research in wood uses is rapidly progressing and some of the so-called “weed trees” may assume considerable importance in the future.

The selection of 50 native trees and 4 introduced species described in this booklet was based chiefly on numerical occurrence and value for timber, shade or ornamental purposes.

The first two plates (pages iv and v) show the types and arrangements of leaves. Outstanding features of individual trees are described in simplified wording and illustrated by accompanying sketches.

Interesting is the fact that pine cones and acorns of the “red or black” oaks ripen in two seasons while fruit from all other trees discussed herein mature in one season.

It is commonly known that no two persons are exactly alike in physical makeup. This is also true of trees since there is some variation in the features within each species.

EXPLANATION OF WORDS, TERMS AND SIGNS
WHICH MAY BE UNFAMILIAR TO READERS

Common and scientific names are from “Standardized Plant Names, 1942.”

Capsule. A dry fruit which contains more than one seed and splits open when ripe.

Catkin. A compound bloom consisting of scaly bracts and flowers usually of one sex.

Downy. With very short and weak soft hairs.

Drupe. A fleshy one-seeded fruit, with the seed enclosed by a hard covering.

Evergreen (leaves). Remaining green throughout the year (older leaves die after 2-15 years).

Fissure. Furrow. A groove or crack.

Leaflet. A leaflike part or blade of a compound leaf.

Leaf Scar. A mark or impression at the point where a leaf had been attached.

Lenticel. A pore on young trunks and branches through which air passes to interior cells.

Lobe (of a leaf). A division or projecting part.

Pith. The spongy material in the center of twigs and young trunks.

Stalked. Having a stem.

Witches’-broom. Abnormal bushy growth of small branches.

Whorl. Three or more leaves or other parts encircling a stem at about the same point.

Small-sized tree. Usually not over 40′ in height when mature.

Medium-sized tree. Usually not over 60′ in height when mature.

Large-sized tree. Usually over 60′ in height when mature.

″ Inch or inches.

′ Foot or feet.

NON-EVERGREEN

SIMPLE

ALL SPECIES INCLUDED IN TEXT, AND NOT LISTED ON THIS PLATE, HAVE SIMPLE LEAVES

COMPOUND

ASH, BLACK

ASH, WHITE

BUTTERNUT

HICKORY, BITTERNUT

HICKORY, MOCKERNUT

HICKORY, PIGNUT

HICKORY, SHAGBARK

HICKORY, SHELLBARK

HONEYLOCUST, COMMON

LOCUST, BLACK

WALNUT, EASTERN BLACK

PALMATELY COMPOUND

HORSECHESTNUT, COMMON

EVERGREEN

HEMLOCK, EASTERN

LARCH, EASTERN (Non-evergreen, single needles arranged in spirals.—See text.)

SPRUCE, NORWAY

SPRUCE, RED

REDCEDAR, EASTERN

PINE, RED

PINE, VIRGINIA

PINE, PITCH

PINE, EASTERN WHITE

OPPOSITE

ASH, BLACK

ASH, WHITE

DOGWOOD, FLOWERING

HORSECHESTNUT, COMMON

MAPLE, NORWAY

MAPLE, RED

MAPLE, SILVER

MAPLE, SUGAR

ALTERNATE

ASPEN, BIGTOOTH

ASPEN, QUAKING

BEECH, AMERICAN

BIRCH, GRAY

BIRCH, PAPER

BIRCH, RIVER

BIRCH, SWEET

BIRCH, YELLOW

BLACKGUM

BUTTERNUT

CHERRY, BLACK

ELM, AMERICAN

ELM, SLIPPERY

HACKBERRY, COMMON

HICKORY, BITTERNUT

HICKORY, MOCKERNUT

HICKORY, PIGNUT

HICKORY, SHAGBARK

HICKORY, SHELLBARK

HONEYLOCUST, COMMON

LINDEN, AMERICAN

LOCUST, BLACK

MAGNOLIA, CUCUMBERTREE

OAK, BLACK

OAK, CHESTNUT

OAK, EASTERN RED

OAK, PIN

OAK, SCARLET

OAK, WHITE

PAWPAW, COMMON

PERSIMMON, COMMON

PLANETREE, AMERICAN

SASSAFRAS, COMMON

TULIPTREE

WALNUT, BLACK

WILLOW, BLACK

WHORLED

CATALPA, NORTHERN

Leaves: Evergreen needles occur singly, spirally arranged on twigs but appear 2-ranked; flattened, about ½″ long; dark green, glossy and often grooved above: light green with 2 white lines below.

Twigs: Slender, rough, yellowish brown to grayish brown. Buds egg-shaped, ¹/₁₆″ long, reddish brown.

Fruit: A cone, ¾″ long, egg-shaped; hangs singly from the tips of the twigs; usually remains attached all winter after ripening in the fall. Under each rounded scale are 2 small winged seeds.

General: Bark on young trees flaky, thick and roughly grooved when old, grayish brown to reddish brown; used in tanning; inner bark cinnamon-red. A large tree, long-lived; shade-enduring. Wood is important for construction lumber.

The Eastern Hemlock is the official State Tree of the Commonwealth of Pennsylvania.

Leaves: Evergreen needles in clusters of 5, soft, flexible, 3-sided, 2½″-5″ long, bluish green in appearance due to whitish lines. This is the only 5-needle pine native to Pennsylvania.

Twigs: Slender, flexible, with rusty hairs when young, finally smooth. Buds egg-shaped, usually less than ½″ long; gray-brown.

Fruit: A cone, 5″-8″ long, about 1″ thick, no prickles, stalked, drooping, slightly curved, resinous, remains attached for one to several months after ripening in autumn of second season. Each scale usually bears 2 winged seeds which is characteristic of all native pines.

General: Bark on young trees and branches greenish brown and smooth, later darker, grooved and scaly. Produces one whorl of about 3 to 7 side branches each year, a feature which is useful in estimating age. A large and very important timber tree. Wood probably has more uses than that of any other species.

Leaves: Evergreen needles in clusters of 3, stiff, 2½″-5″ long, yellowish green.

Twigs: Stout, brittle, rough, angled in cross-section, golden-brown. Buds egg-shaped, about ½″ long, resinous, red-brown.

Fruit: A cone, 1½″-3½″ long with short stiff prickles, nearly stalkless, often remains attached for 5 years or more after ripening.

General: Thick, rough, grayish brown bark on older trees. A medium-sized tree. Common on poor, sandy soils and areas where forest fires have killed most other trees. Wood used chiefly for railroad ties, mine props, construction lumber, posts and fuel.

Leaves: Evergreen needles in clusters of 2, twisted, stout, relatively short (1½″-3″ long), not numerous on twigs.

Twigs: Slender, curved, flexible, brown to purple with bluish white coating. Buds egg-shaped, usually less than ½″ long, brown, resinous.

Fruit: A cone, 2″-3″ long, prickles small but sharp, edge of scales with darker bands; usually without a stalk; remains attached for 3 or 4 years.

General: Smooth, thin, reddish brown, scaly bark. A small tree; able to grow on poor, dry soils. Common on abandoned farm lands where shale soils predominate. Usually grows in dense pure stands. Often called scrub pine. Wood used chiefly for paper pulp, fuel and mine props.

Leaves: Evergreen needles in clusters of 2, slender, 4″-6″ long, dark green, borne in dense tufts at the ends of branchlets; snap easily when bent double.

Twigs: Stout, ridged, yellow-brown to red-brown. Buds egg-shaped, about ½″ long, brown at first and later silvery.

Fruit: A cone, about 2″ long, without prickles, nearly stalkless, remains attached until the following year.

General: Comparatively smooth, reddish brown bark. Like white pine, it develops one horizontal whorl of side branches each year. A medium to large-sized tree. Valuable timber tree in the northern part of the State; wood used chiefly for construction lumber.

Leaves: Evergreen needles occur singly, spirally arranged on twigs, sharp-pointed, four-sided, usually ¾″ long, dark green.

Twigs: Bright, golden-brown. Buds egg-shaped, darker than twigs.

Fruit: A cylindrical cone, 4″-7″ long, light brown; scales with finely toothed margin, broader than long.

General: Bark relatively thin, reddish brown, scaly, becoming gray-brown but seldom furrowed on old trees. Branchlets on older trees droop. A large tree with a dense, conical crown. A European species that has become a valuable naturalized member of our forests, and extensively planted as an ornamental. Wood used chiefly for paper pulp, boxes, crates and lumber.

Leaves: Evergreen needles occur singly, spirally arranged on twigs, stiff, four-sided, usually ½″ long, dark green; less sharp than Norway spruce.

Twigs: Orange-brown with very fine hairs. Buds egg-shaped, about ⅓″ long, red-brown.

Fruit: A cone, 2″ or less in length, reddish brown, remains attached for one to several months after ripening in the fall.

General: Bark red-brown, rough, scaly. A medium to large-sized tree. Wood used chiefly for paper pulp, boxes, crates and lumber. Frequents swamps; chiefly in northeastern parts of the State. Black spruce (P. mariana) is a similar but smaller native tree.

Leaves: Needles not evergreen; occur singly near the ends of the twigs, elsewhere in clusters of 10 or more; about 1″ long, pale green, turning yellow and falling from the tree during the autumn.

Twigs: At first covered with a bluish white coating, becoming dull brown and with numerous short spurs. Buds round, small, ¹/₁₆″ long, dark red.

Fruit: A cone, about ¾″ long, egg-shaped, upright, often remains attached for several years after ripening in the fall.

General: Bark smooth at first, later becoming scaly, dark brown. A medium-sized tree. Only cone-bearing tree native to Pennsylvania that loses its needles annually. Found locally in moist situations. Wood used chiefly for paper pulp, lumber, posts and railroad ties. European larch (L. decidua) and Japanese larch (L. leptolepis) are more commonly planted in the State. Eastern larch is also known as tamarack.

Leaves: Evergreen, opposite, two types (often on the same tree): the older more common kinds are scale-like and only ¹/₁₆″-³/₃₂″ long, while the young sharp-pointed ones may be up to ¾″ in length; whitish lines on the upper surface.

Twigs: Slender, usually 4-sided, becoming reddish brown. Buds small and not readily noticeable.

Fruit: Bluish berry-like, covered with a whitish powder, about ¼″ in diameter; flesh sweet and resinous: contains 1-2 seeds. Ripens the first year.

General: Bark reddish brown, peeling off in stringy and flaky strips. Usually has a conical crown. Prefers limestone and shale soils. A small to medium-sized tree. Wood used chiefly for fence posts and “cedar chests.” Slow of growth; long-lived.

Leaves: Simple, alternate, 6″-9″ long, 5-9 rounded lobes, not bristle-tipped, smooth above and below. Violet-purple in autumn.

Twigs: Red-gray, often with a grayish coating. Buds rounded, reddish brown, smooth, small; end bud about ⅛″ long, often with gray margins on the scales.

Fruit: A sweet acorn, ¾″-1″ long; cup bowl-like, enclosing ¼ of the nut; cup scales warty.

General: Bark gray, usually with shallow fissures and flat scaly ridges but occasionally roughly ridged without scales. A large and valuable tree. Wood uses similar to those of red oak; in addition, used extensively for liquid containers, including whiskey barrels.

Leaves: Simple, alternate, 4″-8″ long, thick; large rounded teeth, decreasing in size toward the leaf tips; dark green and smooth above, paler and occasionally downy beneath.

Twigs: Orange-brown to red-brown. Buds light brown, edges of scales lighter colored, sharp-pointed, ¼″-½″ long.

Fruit: An acorn, 1″-1½″ long. Cup thin, enclosing ⅓ of the shiny nut; cup scales knobby. Kernel moderately sweet.

General: Bark at first gray and smooth, later brownish gray to dark gray, thick, tough, deep-fissured; rich in tannin. A medium-sized tree, found mainly on poorer soils of hillsides and rocky ridges. Wood of better-formed trees has same uses as the other oaks. Also known as rock oak.

Leaves: Simple, alternate, 5″-8″ long, 7-11 lobes, bristle-tipped; smooth above and below, but occasionally with small tufts of reddish brown hair beneath.

Twigs: Greenish brown to reddish brown. Buds pointed, light brown, smooth.

Fruit: An acorn, ¾″-1¼″ long; cup usually saucer-shaped, about an inch in diameter, covers only ¼ of the nut; cup scales reddish brown, narrow, tight, sometimes fuzzy on the edges. Kernel bitter as is true of the next 3 species of oaks.

General: Bark brown and gray, with smooth flat-topped ridges separated by shallow fissures when older. A large and rapid-growing tree. Often planted for shade. Wood has many uses; principally utilized for flooring, railroad ties and construction lumber.

Leaves: Simple, alternate, 4″-7″ long, 7-9 rather narrow, bristle-tipped lobes; smooth except for small tufts of hair beneath. Very deep spaces between lobes. Generally turn scarlet in autumn.

Twigs: Reddish brown, smooth when mature. Buds blunt-pointed, usually round in cross section, dark reddish brown; upper half wooly.

Fruit: An acorn, ½″-1″ long, kernel white; cup thin, bowl-like, covering about ½ of the nut; cup scales sharp-pointed, smooth, tight.

General: Bark on young trees, smooth, light brown; on older trunks ridged, darker. Inner bark reddish. Drooping dead lower branches persist for many years. A medium to large-sized tree, commonly found on dry soils. Wood inferior to red oak, but often sold under that name.

Leaves: Simple, alternate, 5″-9″ long, 5-7 lobes, bristle-tipped; dark green and usually shiny above; paler, more or less covered with rusty-brown fuzz beneath. Yellowish brown in autumn. Often confused with those of scarlet oak.

Twigs: Reddish brown, usually fuzzy. Buds blunt-pointed, ridged, yellow-gray, wooly.

Fruit: An acorn, about ¾″ long, kernel yellow; cup bowl-like, covering from ⅓ to ½ or more of the nut; cup scales sharp-pointed, form a loose fringe at the rim, covered with whitish wooly hairs.

General: Bark on young stems smooth, dark brown; on older trunks dull black, furrowed, forming irregular blocks. Inner bark orange-yellow. A medium to large-sized tree. Wood has the same uses as that of red oak.

Leaves: Similar to those of scarlet oak but generally smaller, fewer-lobed, with more narrow and deeper spaces between lobes. Smooth on both surfaces.

Twigs: Dark red-brown, shiny, slender, often thorn-like. Buds rounded, smooth, smaller than those of scarlet oak.

Fruit: An acorn, about ½″ long, often striped with dark lines; cup thin, saucer-shaped, encloses about ⅓ of nut; cup scales tight, dark-margined.

General: Bark grayish brown, rather smooth for many years; old trunks with shallow fissures and narrow flat ridges. Medium-sized and highly valued street tree. Frequents wet woodland sites. Has the smallest leaves, buds and acorns of all native oaks. Drooping dead lower branches persist for many years. Wood has same uses as red oak but is less desirable because of numerous branch knots.

Leaves: Simple, alternate, 3″-4″ long, sharp-toothed, leathery; light green and glossy above, yellow-green with silky hairs below; veins prominent, parallel. Some leaves often cling to the branches all winter.

Twigs: Slender, brownish gray. Buds reddish brown, sharp-pointed, cigar-shaped; end bud ¾″-1″ long.

Fruit: A shiny brown triangled nut, ½″-¾″ long, usually two enclosed in a stalked prickly bur which splits into 4 parts when ripe; edible.

General: Bark smooth, never furrowed, bluish gray throughout life, with dark blotches when older. A large tree. Most numerous in the northern part of the State. Wood used mainly for railroad ties, paper pulp, boxes, furniture and flooring.

Leaves: Simple, opposite, 5-lobed, about 4″ in diameter; smooth, bright green, paler below; margin with few large teeth.

Twigs: Reddish brown to light brown. Buds brown, sharp-pointed; narrowly cone-shaped.

Fruit: Consists of 2 winged seeds on a stalk; borne in clusters, brown, seed wings ½″ to 1″ long, almost parallel to each other; matures in autumn. Fruit stalks and sometimes the seeds persist into the winter.

General: Bark grayish, on older trunks ridged or with long, thick, curled plates. A large, long-lived, desirable timber and shade tree. Wood used for furniture, flooring; “tapped for sap for making maple syrup.” Often called hard maple.

Leaves: Simple, opposite, generally 3-lobed; about 4″ in diameter; margin with many small teeth.

Twigs: Shiny, green when young, becoming red, with numerous light spots (lenticels). Leaf buds dark red, blunt-pointed; flower buds round, clustered.

Fruit: Paired winged seeds suspended on a slim stem; reddish brown; wing 1″ or less in length; matures in late spring.

General: Bark on young trees gray and smooth, on older trees becoming darker and with long scaly ridges. A medium-sized tree. Common on both swampy and dry sites. A showy tree, usually with reddish flowers and reddish fruit in the spring, and crimson leaves in autumn. Wood has uses similar to those of sugar maple except where strength and hardness are of importance. Often called soft maple.